Khảo sát hàm lượng chất chống Oxy hóa - Ethoxyquin có trong tôm ở một số chợ trên địa bàn Thành phố Cần Thơ

7/26/2019 Kho st hm lng cht chng Oxy ha - Ethoxyquin c trong tm mt s ch trn a bn Thnh ph Cn Th

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TRNG I HC CN TH

KHOA S PHM

ti

KHO ST HM LNG CHT CHNG OXY

HA - ETHOXYQUIN C TRONG TM MT

S CH TRN A BN THNH PH CN TH

Lun vn Tt nghip

Ngnh: S PHM HA HC

Gio vin HD: Sinh vin thc hin:

TS. Nguyn Th Thu Thy Tn:V Th Thy An

Th.S L Bo Ngc MSSV:2091948

Lp: S phm Ha Hc K35

Cn Th 5/2013

WW.DAYKEMQUYNHON.UCOZ.COM WWW.FACEBOOK.COM/DAYKEM.QUYNHON

WWW.BOIDUONGHOAHOCQUYNHON.BLOGSPOT.COMng gp PDF bi GV. Nguyn Thanh T


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Lun vn tt nghip SVTH: V Th Thy An

LI CM N----- ------

Trong sut thi gian thc hin ti lun vn tt nghip, ti gp khng t

kh khn. Ngoi s n lc, phn u ca bn thn trong vic tm ti, hc hi v nghin

cu th chnh s quan tm, ng vin v gip ca gia nh, thy c, bn b l ng

lc ti vn ln v t c kt qu tt nht. Ti xin gi li cm n chn thnh

n:

C Nguyn Th Thu Thy B mn S Phm Ha Hc Khoa S Phm

trc tip hng dn ti. C tn tnh gip , quan tm, ng vin v to mi

iu kin thun li nht ti hon thnh ti tt nghip. C L Bo Ngc Gim c Trung Tm Dch V Phn Tch Th Nghim

TP.HCM chi nhnh Cn Th gip ti v to iu kin thun li v trang

thit b, dng c, ha cht ti hon thnh ti.

Tp th cc thy c B mn Ha - Khoa S Phm truyn th nhng kin

thc, kinh nghim trong sut bn nm i hc.

Cc anh ch lm vic ti Trung Tm Dch V Phn Tch Th Nghim TP.HCM

chi nhnh Cn Th, c bit l cc anh trong phng Sc K nhit tnh gip

v chia s nhng kinh nghim b ch trong qu trnh thc hin phn tch mu.

Gia nh v tp th cc bn lp S phm ha kha 35 lun bn cnh, ng h

v chia s nhng kh khn, vt v trong sut thi gian qua.

Xin chn thnh cm n!

Cn Th, thng 05 nm 2013

Sinh vin thc hin

V Th Thy An




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ii

TRNG I HC CN TH CNG HA X HI CH NGHA VIT NAMKHOA S PHM c lp T do Hnh phcB MN HA HC

NHN XT V NH GI CA CN B HNG DN

1. Cn b hng dn: Ts. Nguyn Th Thu Thy

2. Tn ti: Kho st hm lng cht chng oxy ha- ethoxyquin c trong tm

mt s ch trn a bn thnh ph Cn Th3. Sinh vin thc hin: V Th Thy An MSSV: 2091948

Lp S phm Ha hc K35

4. Ni dung nhn xt:

a. Nhn xt v hnh thc LVTN:

...............................................................................................................................................

...............................................................................................................................................

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...............................................................................................................................................

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b. Nhn xt v ni dung ca LVTN:

- nh gi ni dung thc hin ti:

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................-Nhng vn cn hn ch:

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

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iii

c. Nhn xt i vi tng sinh vin tham gia thc hin ti (ghi r tng ni dung

chnh do sinh vin no chu trch nhim nu c):

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

d. Kt lun, ngh v im:

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

Cn Th, ngy....thng.nm 2013

Cn b hng dn

Ts. Nguyn Th Thu Thy




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TRNG I HC CN TH CNG HA X HI CH NGHA VIT NAMKHOA S PHM c lp T do Hnh phcB MN HA HC

NHN XT V NH GI CA CN B PHN BIN

1. Cn b phn bin:Phan Thnh Chung

2. Tn ti:Kho st hm lng cht chng oxy ha - ethoxyquin c trong tm

mt s ch trn a bn thnh ph Cn Th.3. Sinh vin thc hin:V Th Thy An MSSV:2091948

Lp S phm Ha hc K35

4. Ni dung nhn xt:

a. Nhn xt v hnh thc LVTN:

ti gm55 trang k c phn ph lc v ti liu tham kho. Vn bn c in

n p v ng qui cch.

Tuy nhin cn sa cha: Vit thm phn tm tt ti. Trong phn ny cn nu

mt cch tm lc mc ch v gii hn, ni dung v kt qu, kt lun ca ti.

b.Nhn xt v ni dung ca LVTN:

-nh gi ni dung thc hin ti:

Trong phn m u, tc gi nu r v c th mc tiu v gii hn ca ti,

phng php v phng tin nghin cu.

ti chn phng php sc k lng ghp khi ph (LC/MS/MS) xcnh

d lng Ethoxyquin l cht ph gia chng oxy ha cho thc n chn nui ni chung

v nui trng thy sn ni ring m d lng ca n trong cc sn phm thy sn

c qui nh nghim ngt. Cc kt qu phn tch trn mt s mu tm th trngthnhph Cn Th cho thy d lng Ethoxyquin vt mc qui nh chim mt t l

kh ln. Phng php nh lng d lng Ethoxyquin s dng l mt phng

php phn tch vi phng tin hin i nn kt qu c th tin cy c. y l mt

thng tin c gi tri vi ngi tiu dng a phng thnh ph Cn Th trong vic

s dng tm lm thc phm v cc c s nui tm v xut khu tm cn quan tm

ng mc.

-Nhng vn cn hn ch:




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Tc gi cha nu c cc kt qu ca cc nghin cu trc y v s dn g

phng php sc k lng ghp khi ph (LC/MS/MS) xc nh d lng

Ethoxyquin chng minh rng phng php ny l la chn thch hp.

c. Nhn xt i vi tng sinh vin tham gia thc hin ti (ghi r tng ni

dung chnh do sinh vin no chu trch nhim nu c):

...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

d. Kt lun, ngh v im:

Nhn chung, tc gi hon thnh c bn mc tiu ca ti ra.

Cn Th, ngy.... thng .nm 2013

Cn bphn bin

Phan Thnh Chung




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MC LC----- -----

TrangMC LC ....................................................................................................................... i

DANH MC VIT TT ............................................................................................... iv

DANH SCH HNH ...................................................................................................... v

DANH SCH BIU BNG ......................................................................................... vi

TM TT NI DUNG ............................................................................................... vii

Phn 1: M U ........................................................................................................... 1

Phn 2: NI DUNG ....................................................................................................... 3

A. L THUYT............................................................................................................... 3

I. I CNG V PHNG PHP PHN TCH SC K .................................. 3

I.1. Lch spht hin sc k ...................................................................................... 3

I.2. Phn loi phng php sc k ............................................................................ 3

I.3.1. Phn loi sc k theo bn cht ca hai pha sdng.................................. 3

I.3.2. Phn loi sc k theo bn cht ca hin tng xy ra trong qu trnh tch

cht ..................................................................................................................... 4

I.3.3. Phn loi sc k theo cu hnh ................................................................... 4

I.3. Mt si lng c trng cho phn tch sc k ................................................ 4

I.3.1. H s phn b ( Partition coefficient) ......................................................... 4

I.3.2. Thi gian lu ( Retention time) ................................................................... 5

I.3.3. H s dung lng k (Capacity factor) ....................................................... 6

I.3.4. S a l thuyt............................................................................................ 6I.3.5. chn lc ................................................................................................. 7

I.3.6. phn gii ................................................................................................ 7

II. H THNG MY SC K LNG GHP KHI PH (HPLC/MS/MS)............. 8

II.1. S lc v h thng sc k lng (HPLC) ........................................................... 8

II.1.1.Bnh cha pha ng.................................................................................... 9

II.1.2.B kh kh Degases ..................................................................................... 9

II.1.3.Bm cao p................................................................................................ 10




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II.1.4.B phn tim mu...................................................................................... 10

II.1.5. Ct sc k .................................................................................................. 10

II.1.6.u d ....................................................................................................... 11

II.1.7.B phn ghi nhn tn hiu ......................................................................... 11

II.1.8.In d liu ................................................................................................... 11

II.2. u d khi ph - u d MS ba t cc .......................................................... 12

II.2.1.Mt s vn chung v u d khi ph.................................................. 12

II.2.2. Cu to u d khi ph ba t cc ........................................................... 13

II.2.3.Mt s k thut ghi ph trong u d khi ph........................................ 17

III. Tng quan v gc t do v cht chng oxy ha trong thc phm ......................... 18

IV.Gii thiu v ethoxyquin ......................................................................................... 19IV.1. Cng thc cu to v mt s tnh cht ca Ethoxyquin............................ 19

IV.2. ng dng v nh hng ca Ethoxyquin ................................................. 19

IV.3. Gii hn cho php ..................................................................................... 20

IV.4. Mt s nghin cu v ethoxyquin............................................................. 20

IV.4.1.Nghin cu trn ng vt.......................................................................... 20

IV.4.2.Nghin cu trn thc vt........................................................................... 21

V. Cc phng php xc nh hm lng ethoxyquin ............................................... 22

V.1. Phng php tham kho AOAC 2007.01 .......................................................... 22

V.2. Phn tch d lng ethoxyquin bng my HPLC............................................. 23

V.3. Phn tch d lng ethoxyquin bng my HPLC/MS/MS ................................ 23

B. THC NGHIM .................................................................................................... 24

I. Cc thit b, dng c v ha cht ............................................................................ 24

I.1. H thng my LC/MS/MS ................................................................................ 24I.2. Cc thit b v dng c ...................................................................................... 24

I.3. Ha cht ............................................................................................................. 24

II. Chun b cc dung dch chun ................................................................................ 25

II.1. Dung dch chun gc ......................................................................................... 25

II.2. Dung dch chun trung gian .............................................................................. 25

II.3. Dung dch chun lm vic ................................................................................. 25

III. Chn lc cc yu t trong phn tch ....................................................................... 26

III.1. Kho st khong tuyn tnh ........................................................................ 26




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III.2. Kho st chnh xc ca phng php ................................................... 26

III.2.1.Chun b mu kim sot............................................................................ 27

III.2.2.X l mu ................................................................................................... 28

III.2.3.Cc thng s ci t ca my HPLC/MS/MS........................................... 28

III.2.4.Cng thc tnh ton kt qu ..................................................................... 29

III.2.5.Kt qu kho st chnh xc ca phng php ..................................... 30

IV. Thu mua mu .......................................................................................................... 31

V. Kt qu phn tch .................................................................................................... 31

V.1. Kt qu phn tch d lng cht chng oxy ha - ethoxyqiun trn nn mu tm

s ........................................................................................................................... 32

V.2. Kt qu phn tch d lng cht chng oxy ha ethoxyqiun trn nn mu tmth ........................................................................................................................... 33

Phn 3: KT LUN V NGH ............................................................................. 35

I. KT LUN ............................................................................................................. 35

II. NGH ................................................................................................................ 36

PH LC ..................................................................................................................... 37

TI LIU THAM KHO ............................................................................................ 54




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DANH MC VIT TT

AOAC

Association of Offical Analytical Chemists - Hip hi cc nh

phn tch Ha hc

APCIAtmospheric Pressure Chemical Ionization - Ion ha ha hc

p sut kh quyn

ESI Electrospray Ionization - Ion ha bng cch phun ion

EU European - Lin minh Chu

FDAAmerica Food and Drug Administration - Cc qun l thc phm

v dc phm

HPLCHigh Performance Liquid Chromatography - Sc k lng hiu

nng cao

LOD Limit of detection - Gii hn pht hin

LOQ Limit of quantitation - Gii hn nh lng

Ppb Parts per billion

Ppm Parts per million

PSA Primary secondary amine

MRL Maximum Residue LimitsGii hn cho php

MS Mass spectroscopy - Khi ph

SPE Solid phase extraction - Chit pha rn

UV Ultra Violet - Cc tm




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DANH SCH HNH

Trang

Hnh 1.Thi gian lu ca cu t phn tch ..................................................................... 5Hnh 2.Peak sc k .......................................................................................................... 7

Hnh 3.S h thng HPLC ......................................................................................... 8

Hnh 4. Nguyn l hot ng ca u d MS/MS ........................................................... 13

Hnh 5.Cu to u d khi ph ba t cc ca hng Agilent ......................................... 14

Hnh 6.S to ion dng bng ngun ESI ................................................................. 15

Hnh 7.B ion ha ha hc ............................................................................................. 16

Hnh 8.Hthng u d tcc ....................................................................................... 17Hnh 9.Cc cht chuyn ha ca ethoxyquin l ........................................................... 22

Hnh 10. ng chunEthoxyquin ................................................................................. 26




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DANH SCH BIU BNG

Bng 1.Phn loi sc k theo bn cht ca hai pha sdng ............................................. 3

Bng 2.Gii hn cho phpca ethoxyquin trong mt s thc phm ............................... 20

Bng 3. Kt qu dng ng chun Ethoxyquin ............................................................. 26

Bng 4.Kt qu kho st ngca phng php ........................................................ 30

Bng 5.Kt qu kho st chm ca phng php ....................................................... 30

Bng 6.S lng mu thu mua cc ch trn a bn thnh ph Cn Th.................... 31

Bng 7.Kt qu phn tch tng hp d lng cht chng oxy ha ethoxyqiun trn c

hai nn mu tm sv tm th .......................................................................................... 32Bng 8. Kt qu phn tch d lng cht chng oxy ha ethoxyqiun trn nn mu tm

s ........................................................................................................................................ 32

Bng 9.D lng ca mt s mu nhim ethoxyquin trn nn mu tm s.................... 33

Bng 10.Kt qu phn tch d lng cht chng oxy ha ethoxyqiun trn nn mu

tm th ............................................................................................................................... 33

Bng 11.Kt qu phn tch d lng cht chng oxy ha ethoxyqiun trn nn mu

tm th ............................................................................................................................... 34




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TM TT NI DUNG

Nht Bn l th trng tiu th tm hng u ca Vit Nam. Tuy nhin, vic

xut khu tm sang Nht Bn vi nm tr li y gp khng t kh khn. Nm 2012

va qua, Nht Bn cho kim tra hm lng cht chng oxy ha Ethoxyquin c trongtm ca Vit Nam. Mc d, Ethoxyquin vn cha c nghin cu trn ngi nhng

c mt vi nghin cu trn vt nui cho thy Ethoxyquin c nh hng n sc

khe vt nui, iu cho thy kh nng Ethoxyquin nh hng n sc khe con

ngi cng rt cao. Nu ngi tiu dng s dng lu ngy cc loi tm c cha cht

bo qun ni chung v Ethoxyquin ni ring th s rt c hi cho sc khe v c th

gy ra mt s bnh ngi, vic tm hiu nguyn nhn ca cc bnh ny th rt kh

khn. y cng l mt vn gy nhiu bc xc hin nay.

ti Kho st hm lng cht chng oxy ha - ethoxyquin c trong tm

mt s ch trn a bn thnh ph Cn Th c thc hin vi mc chnhgi c phn no d lng ca cht chng oxy ha ethoxyquin c trong tm mt

s ch thuc a bn thnh ph Cn Th v gip cc nh sn xut nng cao cht lng

tm cung cp cho th trng trong nc v ngoi nc. Do thi gian v iu kin

thc hin nn gii hn ca ti l ch kho st nhng mu tm nguyn liu (tm sv tm th) th trng Thnh ph Cn Th. Ni dung thc hin:

Bc 1: Chn lc cc yu t phn tch.

Bc 2: Thu mua mu mt s ch trn a bn Thnh Ph Cn Th.

Bc 3: X l mutheo nguyn tc: mu sau khi c ng nht, chitxut bng ACNv lm sch bng phng php QuEChERS.

Bc 4: Phn tch mu bng my LC/MS/MS v x l kt qu.

Sau thi gian thc hin ti xy dng cc thng s, chn lc iu kin tiu cho qu trnh thc nghim. Kt qu ph hp vi tiu chun ca AOAC:

Gii hn pht hin LOD = 3ppb.

ng chun tuyn tnh trong khong nng 116ppb.

Hiu sut thu hi nm trong khong t 60 115%.

Thu mua v phn tch 56 mu tm, c 22/56 mu pht hin d lng

ethoxyquin. Trong c 12/22 mu c d lng cao hn MRL, 10/22 mu c dlng thp hn MRL.




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T kt qu thu c ta thy:

T l mu c d lng ethoxyquin vt mc cho php vn cn cao.

Vic s dng ethoxyquin nh mt cht chng oxy ha vn cn rt ph

bin.




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Phn 1: M U

I. L DO CHN TI

Vit Nam, ngnh nui tm c pht trin t rt lu, tp trung ch yu

vng chu th sng Hng, sng Cu Long v vng Duyn Hi. Tuy nhin, giai onu din tch nui tm cn hn ch cho n cui th k XX, khi nhu cu tm cung cp

cho th trng, cc nh hng, nh my ch bin thy sn,... tng cao th c s pht trin

nhanh chng v din tch nui tm. Ngnh nui tm pht trin ngy cng mnh, tm

khng ch cung cp cho th trng trong nc m dn tin ra th trng nc ngoi

nh Nht Bn, EU, Mv tr thnh mt trong nhng mt hng xut khu ch lc

ca Vit Nam.

Nhiu nm qua, Nht Bn l th trng tiu th tm hng u ca Vit Nam.

Tuy nhin, vi nm gn y vic xut khu tm sang Nht Bn gp khng t kh khn

do Nht Bn lin tip a ra nhng ro cn k thut i vi tm ca Vit Nam. C th

l nm 2010, Nht Bn cho kim tra hm lng Trifluralin i vi tt c cc sn phm

tm t Vit Nam. Nm 2011, d lng Enrofloxacin tr thnh vn ln i vi cc

doanh nghip xut khu tm sang Nht Bn. n nm 2012, Nht Bn li kim tra

hm lng Ethoxyquin (cht c s dng lm cht chng oxy ha trg thc n chnnui) i vi cc l tm nhp khu t Vit Nam. Vic Nht Bn xy dng mt ro cn

k thut mi gy khng t tr ngi cho ngi nui cng nh cc doanh nghip xut

khu tm Vit Nam.

Xut pht t thc trng ny, chng ti tin hnh ti: KHO ST HM

LNG CHT CHNG OXY HA - ETHOXYQUIN C TRONG TM

MT S CH TRN A BN THNH PH CN TH. ti c tin hnh

ti TRUNG TM DCH V PHN TCH TH NGHIM TP HCM - CHI NHNH

CN TH .

II.

MC CH CA TI

ti c thc hin nhm mc chnh gi c phn no d lng ca

cht chng oxy ha ethoxyquin c trong tm mt s ch thuc a bnthnh ph

Cn Th. ng thi, gip cc nh sn xut nng cao cht lng tm cung cp cho

th trng trong nc v ngoi nc.

III. MC TIU CA TI




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c ti liu tm hiu v phng php sc k, cht chng oxy ha ethoxyquin v

cc thng tin c lin quan n ti.

Chn phng php thc hin ti.

Tin hnh thu mu tm i din ti cc ch trn a bn thnh ph Cn Th.

Tin hnh x l mu v phn tch hm lng ca cht chng oxy ha -

ethoxyquin c trong mu thu mua bng phng php sc k lng ghp khi

ph.

So snh hm lng ethoxyquin phn tch c vi gii hn cho php v a ra

kt lun.

IV. I TNG NGHIN CU

ti c tin hnh trn nn mu l tm s v tm th (tm nguyn liu).

V.

PHNG PHP NGHIN CU

iu tra: thu mu ngu nhin trn th trng.

Tng kt kinh nghim: c, tham kho ti liu t cc nghin cu trc.

Thc nghim trong phng th nghim: phng php sc k lng ghp khi ph.

VI. GII HN TI

Ch kho st nhng mu tm nguyn liu th trng thnh ph Cn Th.

VII. CC BC THC HIN TI

Giai on 1: Nhn ti, tm ti liu c lin quan n ti, vit cng.

Giai on 2: Thc hin ti.

Giai on 3: Thu thp kt qu, x l s liu, vit bi, bo co.

Ni thc hin ti:PTN Trung Tm Phn Tch Dch V Th Nghim TP H Ch

Minh chi nhnh Cn Th (Case Cn Th).




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Phn 2: NI DUNG

A. L THUYT

I. I CNG V PHNG PHP PHN TCH SC K[1], [4], [5], [7], [12]

I.1.

Lch spht hin sc k

Sc k l mt k thut c ng dng trong nhiu ngnh khoa hc. Nh thc

vt hc ngi Nga Mikhail Tswett pht minh ra k thut sc k vo nm 1903. Cc

cht c Tswett nghin cu l cc sc t thc vt v phng php c ng s dng

l sc k ct vi pha tnh l canxi cacbonat, cn ete du m c dng lm pha di

ng. ng t tn cho k thut ny l chromatography. Tn ny c ghp bi hai

t Hy Lp chroma c ngha l mu v graphein ngha l vit. Trong my thp

k tip theo, nghin cu v l thuyt v ng dng ca sc k pht trin rt mnh

m.

Tt c cc loi hnh sc k u c nguyn l tch ging nhau: mu phn tch

c ha tan trong mt pha ng, pha ny c th l mt cht kh, cht lng hoc cht

lng siu ti hn.Pha tnh c c nh trong ct hay trn b mt vt rn. Cho pha

ng di chuyn qua pha tnh mt cch lin tc v khng ha ln vi n, khi , cc

cht tan l thnh phn ca mu s di chuyn qua ct theo pha ng vi tc khcnhau ty thuc vo tng tc gia pha tnh, pha ng v cht tan. Nh tc di

chuyn khc nhau, cc thnh phn ca mu s tch ring thnh di, lm c s cho phn

tch nh tnh v nh lng.

I.2. Phn loi phng php sc k

Ngi ta phn bit nhiu loi kthut sc k khc nhau da vo bn cht ca

hai pha sdng hoc da vo bn cht ca cc hin tng xy ra trong qu trnh tch

cc cht.

I.3.1.

Phn loi sc k theo bn cht ca hai pha sdng

Pha ng Pha tnh Tn gi ca k thut sc k

Cht lng Cht rn Sc k lng-rn (sc k ct, sc k lp mng).

Cht lng Cht lng Sc k lng-lng (Sc k HPLC vi ct nhi pha o C-18).

Cht kh Cht rn Sc k kh-rn (gi chung l sc k kh)

Cht kh Cht lng Sc k kh-lng (gi chung l sc k kh)

Bng 1. Phn loi sc k theo bn cht ca hai pha sdng




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I.3.2.

Phn loi sc k theo bn cht ca hin tng xy ra trong qu trnh tch

cht

Phn loi sc k theo bn cht ca hin tng xy ra trong qu trnh tch cht

gm cc loi sau:

+ Sc k hp phhay sc k lng rn (adsorption/liquid chromatography).

+

Sc k phn b (partition chromatography).

+

Sc k ion (ion chromatography).

+

Sc k ry phn t (size exclusion/gel permeation chromatography).

Trong , sc k phn b (SKPB) c ng dng nhiu nht v c th phn tch

c nhng hp cht t khng phn cc n nhng hp cht rt phn cc v hp cht

ion c khi lng phn t khng qu ln (


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5

Hng s cn bng K cho cn bng ny c gi l t l phn b hay hng s

phn b v c tnh nh sau:

M

S

C

CK

Vi CS: nng cu t trong pha tnh.

CM: nng cu t trong pha ng.

Tr s K cng ln, s di chuyn ca cht tan qua pha tnh cng chm. Nu cc

cht trong hn hp c hng s K khc nhau cng nhiu, th kh nng tch din ra cng

d dng. H s K ty thuc vo bn cht pha tnh, pha ng , cht phn tch v nhit

.

I.3.2.

Thi gian lu ( Retention time)Cc cht tan trong hn hp mu phn tch khi c np vo ct sc k th

chng sblu gitrn pha tnh trong mt thi gian nht nh gi l thi gian lu.

Thi gian lu ny c tnh tlc np mu vo ct tch sc k cho n lc cht tan

c ra gii hon ton ra khi ct, ti thi im cht phn tch c nng cc

i.

Hnh1. Thi gian lu ca cu t phn tch

0' ttt RR

tR: thi gian lu ca mt cu t t khi vo ct n khi tch ra khi ct.

tO: thi gian cho nhng chtkhng c i lc vi pha tnh i qua ct, cng

l thi gian pha ng i t u ct n cui ct v cn gi l thi gian lu

cht.

tR': thi gian lu tht ca mt cu t.




20/69


6

I.3.3.H s dung lng k (Capacity factor)

H s kl mt thng s quan trng m t tc di chuyn ca cht phn tch

qua ct. H s kcn c gi l h s phn b khi lng gia hai pha:

M

S

MM

SS

V

V

KVC

VC

k .

.'

Hayo

oR

t

ttk

'

Vi VS : th tch pha tnh.

VM: th tch pha ng.

Nu tR tO th k 0: cht ra rt nhanh, ct khng c kh nng gi cht li.

Nu k cng ln (tR cng ln): cht trong ct cng lu, thi gian phn tchcng lu, mi c kh nng b t.

Khong k l tng l t 1-5, nhng khi phn tch mt hn hp phc tp, k c

th chp nhn trong khong rng t 1-20.

I.3.4.

S a l thuyt

S a l thuyt N ca ct c trng cho kh nng tch mi sc k ca cc cu

t trn ct. N cng ln, hiu nng tch cng cao .

S a l thuyt c th o trn sc k . Ngi ta chng minh c:

2

2/1

54.5

W

tN

R

Hay

2

16

W

tN

R

Vi tRl thi gian lu

W1/2 l chiu rng mi sc k v tr chiu cao mi.

W l chiu rng mi sc k v tr y mi.




21/69


7

Hnh 2. Peak sc k

Sa l thuyt cng ln v brng W cng nhth mi sc k cng nhn.

Khi chiu cao ca ct khng i, sa l thuyt tng th hiu nng tch ca ct cng

cao.

I.3.5. chn lc

chn lc l i lng c trng cho kh nngtch cc cu t khc nhau ca

ct.

'

1

'

2

k

k

Nu cng ln hn 1 th hai cht cng d tch ra khi nhau, thng chn

dao ng trong khong 1,052. Nu ln qu thi gian phn tch s ko di.

I.3.6.

phn gii

phn gii (R) c dng nh gi khnng tch hai mi sc k gn

nhau. y l i lng biu th r c ba kh nng ca ct sc k: s gii hp, s chn

lc v hiu qu tch. N c xc nh thng qua phng trnh sau:

)(2

1

)(

12

12

ww

ttR

RR

S

Hay Nk

kRS

)1(

141

'

'

Thi gian

W

tR

W1/2

h

Nng




22/69


8

Vi tR1: thi gian lu ca cu tthnht

tR2: thi gian lu ca cu tthhai

W1: brng y ca mi sc k thnht

W2: brng y ca mi sc k thhai.

: chn lc ca ct sc k cho hai cu t1 v 2.

N: l s a l thuyt.

RS 0,75: Hai peak cha tch nhau.

RS= 1: Hai peak cha tch hn, ch phn tch khi nhau khong 95%.

RS 1.5: Sphn gii c coi l hon ton (99.7%).

II.

H THNG MY SC K LNG GHP KHI PH(HPLC/MS/MS)

II.1. S lc v h thng sc k lng (HPLC)[1], [2], [5], [11]

Nguyn tc hot ng ca my HPLC: mu sau khi c tim vo ct s c

pha ng ko qua ct. Da vo kh nng tng tc gia cc cht c trong nn mu vi

pha tnh v pha ng m chng c tch khinhau. Sau khi ra khi ct, dung dch

mu phn tch s i qua mt ng dn n u d.

H thng sc k lng hiu nng cao gm c cc b phn c bn nh sau:

Hnh 3. S h thng HPLC

Trong :

1: Bnh cha pha ng.2: B phn kh kh

Khkh

Ct

u d

Timmu




23/69


9

3: Bm cao p

4: B phn tim mu

5: C sc k (pha tnh)

6: u d

7: H thng my tnh c phn mm ghi nhn tn hiu, x l d liu v iu

khin h thng.

8: In d liu.

II.1.1.Bnh cha pha ng

H thng pha ng thng c 4 ng dung mi vo u bm cao p cho php

chng ta s dng 4 bnh cha dung mi cng mt ln ra gii theo t l mong mun

v tng t l ca 4 ng l 100%. Trc khi s dng, cn lc (mng lc 0,45m) vui kh ha tan trong pha ng v kh ha tan c th lm bin dng peak, gim hiu

lc ct, lm nhiu ng nn. C th loi kh ha tan bng cch: chy siu m, sc kh

tr nh: heli

C hai cch dng pha ng ra gii:

- ng dng (isocratic): thnh phn pha ng khng thay i trong qu trnh

sc k.

- Gradient: Pha ng l hn hp ca nhiu dung mi, thng l 2-4 loi c

ng trong cc bnh khc nhau. T l cc thnh phn thay i trong qu

trnh sc k theo chng trnh nh (chng trnh dung mi).

Pha ng c th l nc, cc loi dung dch m (pha trong nc), metanol,

acetonnitril hoc hn hp cc loi trn.Pha ng s vn chuyn v tng tc vi cht

cn phn tch, do chng gi vai tr quan trng trng vic tch cc chtphn tch.

Lu : Tt c dung mi dng cho HPLC u phi l dung mi tinh khit sdng cho HPLC. Tt c cc ha cht dng chun b mu v pha h m u phi l

ha cht tinh khit dng cho phn tch. Vic s dng ha cht tinh khit nhm trnh

hng ct sc k hay nhiu ng nn, to nn cc peak tp trong qu trnh phn tch.

II.1.2.B kh kh Degases

Mc ch s dng b kh kh nhm lai tr cc bt khcn st li trong dung

mi pha ng, trnh xy ramt s hin tngsau:

T l pha ng ca cc ng dung mi khng ng lm cho thi gian lu

ca peak thay i.




24/69


10

Trong trng hp bt qunhiu, b kh kh khng th lai tr ht c th

bm cao p c th khng ht c dung mi, khi nh hng n p sut

v hot ng ca c h thng HPLC.

Trong cc trng hp trn udn n sai kt qu phn tch.

II.1.3.Bm cao p

Bm gip to p lc pha ng di chuyn trong h thng, to dng n nh

ngay c khi thnh phn pha ng thay i. p lc bm s dng ty thuc vo tc

dng, nht pha ng, kch thc pha tnh.

Bm phi tt c p sut cao khang 250-600bar v to dng lin tc. Lu

lng bm t 0.1 n 10ml/pht.

Bm c cu to bng cht liu c thchu ng c dung mi hu c vcc dung dch m.

II.1.4.

B phn tim mu

C 2 cch a mu vo trong ct : tim mu th cng (tim bng tay ) v tim

mu t ng (Autosample).

Tim mu t ng: mu lng hoc dung dch c tim thng vo pha ng

cao p ngay u ct (khng cn phi dng dng) bng mt van tim c vng

cha mu. Vng cha mu c dung tch khc nhau: thng dng loi 0,5-

20l. Khi dng van tim s d dng t ng ha, phn mm my tnh d

dng iu khin v kim sot h bmmu t ng. Sai s tim mu dng

van khong 0,5%.

Tim mu th cng: mu c bm bng tim qua tm m u ct. Khi

tim phi dng dng v p sut trong ct khng cao. Cch tim ny c

lp li thp, sai s ln hn nhiu so vi kh dng van tim.II.1.5.

Ct sc k

Ct pha tnh thng thng lm bng thp khng r, thy tinh hoc cht do c

chiu dit 10-30cm, ng knh trong 4-10mm, ht nhi c 5-10m, s a l thyt

dao ng t 40000-60000 a/m. Gn y, ngi ta c loi ct nh vi ng knh

trong 1-2mm, di 3-7,5cm, ht nhi c 3 hoc 5m vi s a l thuyt n 100000

a/m. u im ca loi ct ny l chy sc k t tn dung mi v t thi gian. Cht

nhi ct ph thuc vo loi ct v kiu sc k. Mt s loi cht nhi ct c s dng

nh: silica, nhm oxit, polymer xp, nha trao i ion, Trong silica c s




25/69


11

dng nhiu nht,Cc ht silica gel thng c bao ph mt lp mng hu c lin kt

(ha hc hoc vt l) vi b mt.

Ct bo v c t trc ct sc k loi cc cht c trong pha ng v mu

phn tch c kh nng lm gim tui th ca ct .

II.1.6.u d

L b phn pht hin cc cht khi chng ra khi ct v cho cc tn hiu ghi trn

sc k c th nh tnh v nh lng. Tn hiu u d thu c c th l: hp

th quang, cng pht x, cng in th, dn in, dn nhit, chit

sut,

u d trong sc k lng cn p ng cc yu cu sau:

-

p ng nhanh v lp li.- nhy cao, c th pht hin cht phn tch khi lng hoc nng

thp.

- Vn hnh n nh, s dng d dng.

- Khong hot ng tuyn tnh rng.

- t thay i theo nhit v tc dng.

Hin nay c nhiu loi u d c s dng, trong c mt s loi u d

c s dng ph bin nh:

- u d UV.

- u d hunh quang.

- u d in ha.

- u d khi ph.

II.1.7.B phn ghi nhn tn hiu

B phn ny ghi tn hiu do u d pht hin. i vi cc h thng HPLC hini, phn ny c phn mm trong h thng ghi nhn, lu cc thng s, sc k ,

cc thng s lin quan n peak nh tnh i xng, h s phn gii, ng thi tnh

ton, x l cc thng s lin quan n kt qu phn tich.

II.1.8.In d liu

Sau khi phn tch xong, d liu s c in ra qua myin kt ni vi my tnh

c ci phn mm iu khin.




26/69


12

II.2. ud khi ph- u d MS ba t cc[1], [3], [5], [14]

II.2.1. Mt s vn chung v u d khi ph

Phng php khi ph (Mass Spectrometry-MS) l phng php nghin cu

cc cht bng cch o, phn tch chnh xc khi lng phn t ca cht da trn s

chuyn ng ca cc ion nguyn t hay ion phn t trong mt in trng hoc t

trng nht nh. T s gia khi lng v in tch (m/z) c nh hng rt ln i vi

chuyn ng ny ca ion. Nu bit cin tch ca ion th ta d dng xc nh c

khi lng ca ion .

u d khi ph c ni vi u ra ca ct sc k,tuy nhin, vic ghp my

sc k lng (LC) vo my khi ph (MS) khng th thc hin trc tip c. Nguyn

nhn l do qu trnh phn tch vi u d MS i hi mc chn khng cao, nhit cao, cc cht kho st phi th kh, vn tc dng chy nh trong khi h thng my

LC li hot ng trong iu kin p sut cao, nhit tng i thp, cc cht kho

st th lng,vn tc dng chy ln.

khc phc nhng kh khn trn trong vic ghp hai loi my li vi nhau,

cn phi c mt trung gian l giao din. C nhiu loi giao din khc nhau dng cho

HPLC-MS nh: chm tia ht (PB), bn ph nhanh nguyn t dng lin tc (CF -FAB),

tia nhit (TSP), ion ha bng cch phun ion (ESI), ion ha ha hc p sut kh quyn

(APCI),Ty thuc vo khi lng phn t v c tnh (phn cc hay khng phn

cc) ca hp cht kho st m c th s dng my LC-MS vi cc k thut giao din

khc nhau.

Trong phn tch khi ph, vic xc nh chnh xc mt ion (M+ hay cc phn

mnh) rt quan trng cho vic xc nh cht c phn tch. Mt hp cht xc nh,

trong nhng u kin xc nh s cho cho cc ion xc nh trn khi ph. Tuy nhin,mt ion c s khi xc nh trn khi ph li c th xut pht t nhiu cht khc nhau.

Trong vic phn tch mu bng sc k lng ghp khi ph, nu iu kin sc k

khng m bo, cc cht tch ra khng khng hon ton dn ti khi ph thu c s

c ion ca cc phnt khc lm nh hng ti vic nhn nh kt qu. Trong trng

hp ny, vic xc nh MS thng thng (mt ln) khng cho c kt qu chnh xc.

khc phc, ngita s dng cc k thut khi ph n ln vi n thng l 2 hay i

khi hn. K thut ny c gi l MS/MS hay MSn.Nguyn tc ca k thut ny l

la chn mt ion xc nh (thng l M+ nhng cng c th l cc ion con) trong cc




27/69


13

ion con ca ln ion ha th nht v loi b tt c cc ion khc trong b phn phn tch

ion. Cc ion ny sau c cho tip xc vi mt lng nh cc kh (thng l

argon). Vi vn tc cao, cc ion ny s va p vo cc phn t kh v phn thnh cc

mnh nh hn. Cc ion sinh ra trong ln phn mnh th hai ny s c phn tch v

ghi nhn ph MS. V khi ph ghi nhn c t 1 loi ion duy nht nn khng cn b

nh hng ca cc tp cht trong mu na. Vic nhn nh kt qu trn ph MS/MS s

chnh xc hn, c bit khi hm lng cht phn tch thp v nm trong hn hp phc

tp.

Hnh 4. Nguyn l hot ng ca u d MS/MS

Cc thit b thc hin MS/MS c 2 loi chnh l: khi ph ba t cc v by

ion. Trong ti ny chng ti ch trnh by c th v khi ph ba t cc.

II.2.2.

Cu to u d khi ph ba t cc

u d khi ph c ba b phn chnh l: bung ion ha (ionizer), b tch khi

(mass analyzer) v b d ion (detector).

Ion s cp Ion th cp

B mtphoton

va chm




28/69


14

Hnh 5. Cu to u d khi ph ba t cc ca hng Agilent

a)Bung ion ha

Bung ion ha l ni mu c bin thnh cc ion i vo h thng phn tch.

i vi u d ba t cc c bn ngun to ion p sut kh quyn, l: ESI, APCI,

APPI v MMI. Chng ti ch trnh by c th v hai k thut thng dng l ESI v

APCI.

Ion ha bng cch phun ion (ESI)Trong k thut ESI, dung dch mu phn tch (gm hn hp cht phn tch v

dung mi pha ng) t h thng sc k lng c a vo mt ng mao qun lm

bng thp khng r, di nh hng ca in th cao v s h tr ca kh mang, dung

dch mu phn tch c phun sng ra khi ng mao qun vo mt in trng mnh

(in th c th dng hoc m ty thuc vo vic ngi ta mun kho st ion m hay

dng). Di nh hng ca in th, ti u mao qun, dung dch xut hin thnh

nhng git sng nh, mang in tch. Kh xung quanh cc git ny to mt nhit

nng lm bay hi dung mi ra khi git sng, cc ht mang in tch c th tch nh

dn v do s y nhau gia cc in tch cng du, s b dn thnh cc ht nh mang

in tch. Qu trnh ny c lp li nhiu ln hnh thnh nhng ht rt nh. T

nhng ht rt nh mang in tch cao ny, cc ion phn tch c chuyn thnh th kh

bi lc y tnh in ri sau i vo b phn tch khi.

Trong k thut ESI, phn t nht thit phi c bin thnh cht in ly, tan

trong dung dch dng phun sng. Cc dung mi ph hp phun sng l: etanol,

methanol, isopropanol, acetonitril, acetone, chloroform, diclorometan,




29/69


15

ESI l mt k thut ion ha c ng dng cho nhng hp cht khng bn

nhit, phn cc, c khi lng phn t ln. ESI c kh nng to thnh nhng ion a

in tch (dng hoc m, ty thuc vo p cc in th), c xem l k thut ion

ha m du hn APCI, thch hp cho phn tch cc hp cht sinh hc nh protein,

peptide, nucleotide hoc cc polyme cng nghip nh polyethylen glycol.

Hnh 6. S to ion dng bng ngun ESI

Ion ha ha hc p sut kh quyn (APCI)

Mu hp cht cn phn tch ha tan trong pha ng, sau khi ra khi ct HPLC,

c cho i ngang qua ng mao qun t nng. Khi ra khi ng, dung dch c phun

thnh dng sng. Cc git sng nh c mt dng kh dn n mt ng thch anh

un nng, gi l bung ha kh. Hp cht i theo lung kh nng (120oC) ra khi ng

n vng c p sut kh quyn, ni y s xy ra s ion ha ha hc nh vo mt

que phng in Corona, ti y c s trao i proton bin thnh ion dng (M +H)+v trao i ion hoc electron bin thnh ion m (M - H)-. Tip theo, cc ion s

i vo b phn phn tch khi.

u im ca loi giao din ny l c th chu c vn tc dng chy ca my

sc k 0,5-2 ml/ pht, cng nh bt k loi dung mi no, k c dung dch m khng

bay hi.

APCI l k thut ion ha thng c s dng phn tch nhng hp cht c

phn cc trung bnh, c phn t lng nh, d bay hi.

Ion

Ht sng mang

in tch

B gn lc

Dng kh nit kh, nng

ngphun sng




30/69


16

Hnh 7. B ion ha ha hc

b)B phn phn tch khi

Nhim v ca b phn phn tch khi l phn tch cc ion sinh ra bi b phn

ion ha thnh tng loi ring bit theo m/z a cc ion ny ti detector ghi nhn

ph.

Cu to ca b phn phn tch khi gm 3 t cc ghp ni tip vi nhau. T cc th

nht (Q1) v t cc th ba(Q3) c cu to ging nhau. Mi t cc c cu to bi 4thanh in cc song song to thnh mt khong trng cc ion bay qua. Mt trng

in t c to ra bng s kt hp gia dng mt chiu (DC) v in th tn s radio

(RF). Cc t cc c ng vai tr nh mt b lc khi. Khi mt trng in t c

p vo, cc ion chuyn ng trong n s daong ph thuc vo t s gia m/z v

trng RF. Ch nhng ion c t s m/z ph hp mi c th i qua c b lc ny.

Sau khi ra khi bung ion ha, cc ion sinh ra c tp trung v gia tc bng h

quang hc ion a vo b phn tch khi. Ti b phn tch khi, t cc th nht

(Q1) lm nhim v chn lc ion. Cc ion c chn s bay vo t cc th hai (Q2) v

va p vi dng kh tr phn mnh ion ln hai. Tt c cc ion to ra t cc th hai

(Q2) s bay vo t cc th ba (Q3) v c qut ln lt bi in trng i ti

detector v ghi nhn thnh ph.

p sut kh quyn

Gia nhit

Que phng inCorona

Dung dchphn tch

Kh phunsng

Khng khkh

Bm chn khng

B phn phntch




31/69


17

Hnh 8. Hthng u d tcc

c)B d ion (Detetor)

L ni tip nhn cc ion v bin chng thnh cc tn hiu in c ghi nhn

thnh cc tin hiu ph khi.

II.2.3. Mt s k thut ghi ph trong u d khi ph

a)

Full scanKhi thao tc vi ch scan, u d s nhn c tt c cc mnh ion cho

khi ph ton ion i vi tt c cc cht trong sut qu trnh phn tch. Thng dng

nhn danh hay phn tch khi cht phn tch c nng ln. i vi u d khi

ph ba t cc, ch SCAN thng c la chn kho st ion m.

b) SIM (Selected I on Monitor ing)

Trong ch SIM, u d MS ch ghi nhn tn hiu mt s mnh ion c trng

cho cht cn xc nh. Khi ph SIM ch cho tn hiu ca cc ion c la chn

trc , do vy khng th dng nhn danh hay so snh vi cc th vin c sn.

i vi u d khi ph ba t cc, ch SIM thng c la chn kho st

nng lng phn mnh khi bit ion m.

c)

SRM (Selected Reaction Moni tori ng) v MRM (Multiple Reaction

Monitoring)

i vi khi ph ba t cc, l my o khi ph hai ln lin tip (MS -MS), 2 k

thut ghi ph c nhy cao thng c s dng l SRM v MRM.

Ngun

Ion khng cnghng

Ion cng hng

Hiu in th mtchiuv xoay chiu

u d




32/69


18

- SRM: c lp ion cn chn, sau phn mnh ion c lp , trong cc mnh

ion sinh ra, c lp 1 mnh ion con cn quan tm v avo u d pht

hin.

- MRM: trn thc t, do yu cu v mt k thut i vi phn tch vi lng

nn cc ion con cn quan tm thng t 2 tr ln, do vy k thut ghi ph

MRM thng dng hn SRM. u tin, c lp ion cn chn (ion m) t

cc th nht, phn mnh ion c lp ti t cc th 2 (thc cht l bung

va chm) thu c cc ion con, c lp 2 (hoc nhiu) ion con cn quan tm

t cc th 3 v a vo u d pht hin.

III. Tng quan v gc t do v cht chng oxy ha trong thc phm[6], [15]

Gc t do c khi nim l nhng nguyn t, nhm nguyn t hoc phn t lp ngoi cng c nhng electron khng ghp i. Gc t do c th tn ti c lp, tuy

nhin thi gian tn ti ca gc t do rt ngn ( khong mt phn triu n mt phn

nghn giy). Cc gc t do ny c nng lng cao, rt km bn nn d dng tham gia

vo nhiu phn ng ha hc nh phn ng oxy ha, phn ng polymer ha, lm thay

i cht lng v gi tr ca thc phm.

Cht chng oxy ha lnhng cht c kh nng ngn chn hoc lm chm li

qu trnh oxy ha cht khc. Cht chng oxy ha ngn qu trnh ph hy ny bng

cch kh cc gc t do, km hm s oxy ha bng cch oxy ha chnh chng.

Trong sn xut, bo qun v ch bin thc phm, s oxy ha cht bo l nguyn

nhn ch yu gy gim cht lng thc phm, lm hn ch thi gian bo qun thc

phm. Khi b oxy ha, thc phms c mi i v mt i cc acid bo thit yu v cc

Vitamin tan trong du nh: A, D, E, carotenoids b ph hy lm gi tr dinh dng ca

thc n b gim. Do , hu ht cc sn phm thc phm v thc n chn nuiuc b sung cht chng oxy ha nhn to c ch qu trnh oxy ha. Cc cht

chng oxy ha c thm vo s gip ch cho vic bo qun gi tr dinh dng v

hng v ca thc phm, tngthi hn s dngca sn phm v lm chm qu trnh

oxy ha ca thc phm.

Hinnay, mt s ph giachng oxy ha c s dng ph bin ngn chn

qu trnh oxy ha thc phml: BHA (Butylated Hydroxyanisole), BHT (Butylated

Hydroxytoluene), TBHQ (Tert-Butyl Hydroquinone), Ethoxyquin, Propyl gallate

(PG),




33/69


19

IV. Gii thiuv ethoxyquinEthoxyquin c tn thng mi l Santoquin, santoflex hay EQ. Ethoxyquin

l mt cht chng oxy ha c FDA chp thun v cho php cs dngtrong

thc n chn nui hn 30 nm qua.IV.1. Cng thc cu to v mt s tnh cht ca Ethoxyquin[9], [16]

Cng thc cu to:

6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline

Hay 1,2-dihydro-2,2,4-trimethylquinolin-6-yl ethyl ether

CTPT: C14H19NO

Khi lng phn t: 217,31

Trng thi: cht lng mu hi nu, nht.

Nhit si: 150oC 747 mmHg.

p sut bay hi: 3,46.10-2Pa 25oC

1,18.10-1Pa 35oC

3,32.10-1Pa 45oC

thy phn 25oC:pH=5 thi gian bn hy l 3,7 ngy

pH=7 thi gian bn hy l 6,7 ngy

pH=9 thi gian bn hy l 9,3 ngy

tan (25oC): nc 170mg/l

acetonitrile 462 g/l

n-octanol 452g/lIV.2. ng dng v nh hng ca Ethoxyquin[10], [18]

Ethoxyquin c pht hin vo thp nin 50 bi Monsanto, ethoxyquin c s

dng nh mt loi chng oxi ha cht bo, cht bo qun (E324) trong thc n chn

nui nhm tng tnh n nh cc vitamin tan trong du, m bo cht lng ca thc

n chn nui. Ethoxyquin c hot tnh gip cc sn phm tri cy sau thu hoch hn

ch qu trnh mt mt hm lng carotenoid v vitamin E. Ngoi ra, ethoxyquin cn

c s dng vi mc ch bo qun mu trong sn xut bt t, cht n nh chng

phn hy trong sn xut cao su.




34/69


20

Bn cnh tc dng bo qun,ethoxyquin c ng k s dng nh mt loi

thuc tr su nhm trnh s chuyn mu khng mong mun (thng b chuyn sang

mu nu) i vi tri cy to v l, bng cch phun trc tip trc v sau khi thu

hoch.

Gn y, ti Nht Bn c mt vi nghin cu cho thy ethoxyquin c kh nng

thc yung ththn, ung thbng quang v lm tng ln ng kcc khi uddy

vt nui. Tuy nhin, hin nay cha c bngchng c th no c ghi nhn trn th

gii v kh nng gy ung th ca Ethoxyquin.

IV.3. Gii hn cho php[16], [17]

Hin nay, ty theo mc ch s dng Ethoxyquin trong thc n chn nui hay

trong thc phm m mc quy nh liu lng khc nhau.Tn khu vc/

quc giaTn nn mu Hm lng cho php

EU

Thc n chn nui 150ppm

Cc sn phm thc vt, ng vt trn

cn, lng c, b st0,05ppm

Thy sn 0,1ppm

Hoa K Thc n chn nui 150ppm

Nht BnThc n cho tm 150ppm

Cc sn phm gip xc nh: tm, cua,... 0,01ppm

Hn Quc Tm 0,01ppm

Bng 2. Gii hn cho phpca ethoxyquin trong mt s thc phm

IV.4. Mt s nghin cu v ethoxyquin[9], [15] [16]

IV.4.1.

Nghin cu trn ng vt

Nm 1969, Tchc Nng nghip v Lng thc Lin Hip Quc (FAO) v T

chc Y t Th gii (WHO) cng ban hnh 2 bn bo co (s hiu FAO/

PL:1969/M/17/1 v WHO/Food Add./70.38) v Thm nh mt sd lng thuc

trsu trong thc phm. Trong , ti Chng 159 ni vnghin cu ethoxyquin,

nhiu th nghim c phn tch rt r.

Theo , cc nghin cu trn chut v ch cho thy c xut hin tc dng c

hi trn gan v thn nng ethoxyquin trong thc n t250 ppm tr ln i vi




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chut, v t10 ppm i vi ch. nng thp (khong 50 ppm), ethoxyquin nhanh

chng bch, chut v g bi tit. Ethoxyquin dchuyn ha thnh cht ha tan v

nu qu trnh bi tit xy ra thun li, t c khnng ethoxyquin lu li trong c th.

Trong mt nghin cu khc vo thng 3/2003, Cu lc bChut M(Rat &

Mouse Club of America RMCA) ch ra mt s c tnh khng ung th ca

ethoxyquin. Ethoxyquin trong thc n ca chut c cho l c thngn nga ung th

gan do c taflatoxin gy ra. Aflatoxin l cht gy ung th tnhin phbin trong

thc phm, nht l trong ng v cc loi ht. Chut l loi dbung th nht do nh

hng ca aflatoxin. Ngoi ra, ethoxyquin trong thc n ca chut cng c cho l

yu tgp phn ngn cn stin trin ca cc khi u v.

Theo TS. W. Jean Dodds, Chtch Trung tm Th y Hemopet (M), ng vttrong phng th nghim, ethoxiquin lm tng vitamin gan A t2-5 ln, trong thc n

chn nui vi hm lng cao hn, chng lm tng nng vitamin E trong mu ln 2

ln. Ethoxyquin c nh gi l c tnh cp 3, hay nhm c tnh trung bnh. Nu

nhim phi vi nng t0,55g/kg c thgy tvong ngi.

IV.4.2.

Nghin cu trn thc vt

Ethoxyquin c s dng nh mt loi thuc tr su dng cho mt s loi tri

cy nh l, to,...Sau y l mt scht chuyn ha t ethoxyquin. (Mi tnt on

ch qu trnh trao i cht cho cc sn phm cha c c lp hoc cha c xc

nh chc chn. )




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Hnh 9. Cc cht chuyn ha ca ethoxyquin l.

V.

Cc phng php xc nh hm lng ethoxyquin[19], [20] [21]V.1. Phng php tham kho AOAC 2007.01

Phng php ny c s dng u tin vo nm 2007, p dng cho mt s

loi thuc tr su c trong nho, rau dip v cam nh: atrazine, azoxystrobin,

bifenthrin, carbaryl, chlorothalonil, lorpyrifos, chlorpyrifos-methyl, l-cyhalothrin (pht

sinh trong rau dip), cyprodinil, dichlorvos, endosulfan sulfate,ethion (pht sinh trong

cam), imazalil, Imidacloprid, kresoxim-methyl (pht sinh trong nho) v trifluralin.

Phng php ny cng c p dng cho nhng cht khc tng t nh thuc tr su

trong c ethoxyquin. Gii hn nh lng caphng php l


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Mi gam mu c ha tan vi 1ml acid acetic (1%) trong ACN v 0,5 gam

MgSO4khan/NaOAc (4:1). Cho hn hp trn vo ng nha ri lc v em li tm. Sau

khi li tm, phn dung dch chit xut (lp trn) c cho vo ng nghim c cha

mui MgSO4khan/ cht hp th PSA (3:1, vi 200mg cho 1ml dung dch chit xut),

vortex ri em li tm. Cui cng, dung dch chit xut c cho vo vial v c phn

tch bng GC/MS hoc LC/MS/MS.

V.2. Phn tch d lng ethoxyquin bng my HPLC

Mt phng php mi c pht trin xc nh d lng ethoxyquin

(EQ), QI v DM trong thc n cho c, QI v DM l snphm caqu trnh oxy ha

EQ. Mucchit xutvi hexane, sau thi kh v nh mc vi acetonitrile.

Dung dch mu c phn tch bng sc l lng hiu nng cao (HPLC) vi ct pha oC18, u d UV vi= 280nm. Pha ngc s dng l hn hpacetonitrile 0,01

M v ammonium acetate (80:20).

V.3. Phn tch d lng ethoxyquin bng my HPLC/MS/MS

Ethoxyquin trong mu c chit xut bi hexane sau c phn tch trn

my LC/MS/MS vi ct pha o C18. Pha ng l hn hp acid fomic v ammonium

acetate vi t l thch hp.Ion m c chn c m/z l 218,1 v hai ion con c chn

phn tch nh tnh v nh lng c m/z ln lt l 147,9 v 175,9. Gii hn pht

hin (LOD) l 5ppb. Khong tuyn tnh c chn l 20 200ppb.




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B. THC NGHIM[4], [5], [8], [20]

Xc nh hm lng cht chng oxy ha ethoxyquin c trong tm bng

phng php sc k lng ghp u d khi ph ba t cc (LC/MS/MS).

Nguyn tc

Mu sau khi c ng nht, chit xutbng ACN, lm sch bng phng

php QuEChERS sem phn tch trn my LC/MS/MS Aligent 6410B.

Phm vi p dng

Xc nh hm lng ethoxyquin trong thy sn vi gii hn pht hin LOD =

3ppb v gii hn nh lng LOQ = 9ppb.

I. Cc thit b, dng c v ha cht

I.1.

H thng my LC/MS/MS Bm gradient Binary pump SL.

B tim mu t ng HipALS.

H iu nhit TCCSL.

u d Triple Quad LC/MS/MS 6410B.

Ct XDBC18; 2,7m; 2,1x50 mm v ct bo v hoc tng ng.

I.2. Cc thit b v dng c

My lc STUART.

My ly tm lnh HERMLEZ.

My vortex.

Bn siu m c gia nhit ELMA.

Cn phn tch gram, chnh xc ti 0,0001g.

Cn phn tch miligram, chnh xc ti 0,001g.

Micropipet loi 20-200l v 100-1000 l.

ng nha 50ml chu c dung mi.

Giy lc = 11cm.

Bnh erlen 250ml.

Pipet 1ml, 5ml.

Bnh nh mc 10ml, 25ml,50ml.

I.3.

Ha cht Acetonitril HPLC grade ca Merck.




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Axit fomic 99%

Nc ct 2 ln khng ion.

Mui NaCl v MgSO4ca Trung Quc.

Chun Ethoxyquin ca hng Fluka. Pha ng A: Lc nc ct hai ln kh ion qua h thng lc pha ng vi giy lc

0,45m. Cho vobnh ng mi 4000ml. nh siu m 30 pht.

Pha ng B: Cho acetonitril (ACN) vo bnh cha 4000ml n y vch, nh

siu m 30 pht.

II.Chun b cc dung dchchun

II.1. Dung dch chun gc

Chun Co(100ppm): cn chnh xc 1,022mg chun ethoxyquin, nh mc thnh

10ml bng acetonitril(hm lngtinh khit ca chun gc l 97,8%). Chun lu

trong ti, nhit 4- 8oC, bn trong mt thng.

II.2. Dung dch chun trung gian

Chun trung gian 1 (10ppm): ly 1ml chun Co cho vo bnh nh mc thnh

10ml bng acetonitril. Chun lu trong ti, nhit 4- 8oC, bn trong mt thng.

Chun trung gian 2 (1ppm): ly 1ml chun 10ppm nh mc thnh 10ml bngacetonitril. Chun lu trong ti, nhit 4- 8oC, bn trong mt thng.

Chun trung gian 3 (100ppb): ly 1ml chun 1ppm nh mc thnh 10ml bng

acetonitril. Chun lu trong ti, nhit 4- 8oC, bn trong mt thng.

Chun trung gian 4 (50ppb): ly 5ml chun 100ppb nh mc thnh 10ml bng

acetonitril. Chun lu trong ti, nhit 4-8oC, bn trong mt thng.

II.3. Dung dch chun lm vic

Chun C1: Ly 320l chun 50ppb cho vo bnh nh mc 1ml, thm acetonitril

n vch, lc u s c chun 16ppb.



Chun C3 Ly 80l chun 50ppb cho vo bnh nh mc 1ml, thm acetonitril


Chun C4: Ly 40l chun 50ppb cho vo bnh nh mc 1ml, thm acetonitriln vch, lc u s c chun 2ppb.




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Cc chun C1 C5pha hng ngy.

III.

Chn lc cc yu t trong phn tch

[8]

III.1. Kho st khong tuyn tnh

Khong tuyn tnh ca mt phng php phn tch l khong nng c

s ph thuc tuyn tnh gia i lng o c v nng cht phn tch.

Thc hin

Pha mt dy cc cht chun c nng ln lt l 1; 2; 4; 8; 16ppb. Tin hnh

phn tch trn my sc k v ghi nhn din tch peaktng ng. T s liu thu c s

tnh ton c R2, m bo yu cu v tnh tuyn tnh th R2 0,99.Nng (ppb) 0 1 2 4 8 16

Din tch peak 47 1000 1138 2819 5604 12300

Bng 3. Kt qu dng ng chun Ethoxyquin

y = 751.27x

R2= 0.9955

0

2000

4000

6000

8000

10000

12000

14000

0 2 4 6 8 10 12 14 16 18

Nng (ppb)

dint

chp

eak

Hnh 10. ng chun Ethoxyquin

Trc X: nng dung dch chun (ppb).

Y: din tchpeak tng ng.

III.2. Kho st chnh xc ca phng php

chnh xc (accuracy) = chm (precision) + ng (trueness)




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ng ch mc gn nhau gia gi tr trung bnh ca kt qu th nghim v

gi tr thc hoc gi tr c chp nhn l ng . ng c tnh ton trn t l

phn trm thu hi trong nh lng khi thm vo mt lng cht tan cho bit vo

mu o.

Trong nhiu trng hp cc php th nghim trn nhng i tng v vi

nhng iu kin khc nhau thng khng cho kt qu ging nhau. iuny do cc sai

s ngu nhin ca mi quy trnh gy ra, ta khng th kim sot c hon ton tt c

cc yu t nh hng n kt qu th nghim. Do , kim sot c cc sai s

ny, phi dng n khi nim chm. chm ch mc mc dao ng ca

cc kt qu th nghim c lp quanh tr gi trung bnh. chm ch ph thuc vo

sai s ngu nhin v khng lin quan n gi tr thc. chm l mt khi nim nhtnh v c biu th nh lng bng lch chun hay h s bin thin. chm

cng thp th lch chun hay h s bin thin cng ln.

lch chun SD v lch chun tng i RSD hay h s bin thin CV

c tnh theo cc cng thc sau:

1

)( 2_

n

xSD

xi

RSD% = CV% = 100_

x

SD

Trong :

SD: lch chun

n: Sln th nghim

xi: Gi tr tnh c ca ln th nghim th i

x_

: Gi tr trung bnh ca cc ln th nghim.

RSD%: lch chun tng i.

CV%: H sbin thin

III.2.1. Chun b mu kim sot

Chun b mu trng: mu trng l mu tm c phn tch ethoxyquin nhiu

ln (n=7) v sc k khng c mi ethoxyquin. Mu tm c ng nht v cho vo

ti nilon bo qun -20oC, dng lm mu trng v mu thm chun.Mu trng: cn 2g v x l theo qui trnh III.2.2.




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Mu thm chun (M+C): Mu trng cn 2g, tim vo mu dung dch chun

10ppb ethoxyquin (tim 0,1ml chun C1 200ppb), vortex, yn 30 pht, x l mu

theo qui trnh III.2.2.

III.2.2.X l mu

S tm tt qui trnh x l mu trong ti

III.2.3. Cc thng s ci t ca my HPLC/MS/MS

iu kin ca my HPLC 6410B Pha ng A: H2O

Rt khong 1ml dung dch mu phn tch

cho vo vial

My HPLC/MS/MS

nh vortexLy tm

Lc vo ng nha c cha 0,2g NaCl,0,6g MgSO4 v 0,1g PSA

nh vortexLy tm

Rt 2ml dung dch mu phn tch chovo ng nghim c cha 0,2g MgSO4v

0,1g PSA

nh vortex

Lc 30 phtLy tm

Cn 2g mu cho vo ng nha+ 5ml acetonitril

ng nht mu




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Pha ng B: ACN

Ct XDBC18; 2,7m; 2,1x50 mm

Thi gian (pht) %BTc dng

(ml/pht)0 25% 0,4

4 100% 0,4

10 100% 0,4

Th tch tim: 10l

Time stop: 10 min

Post time: 5 min

iu kin MS

Source: ESI+

Gas temp: 300oC

Gas flow: 10 l/min

Nebulizer: 40psi

Capillary: 4000V

Scan type: MRM

Ion nh lng Ion nh tnh

Ethoxyquin 218,2 148,1 218,2 174,2

Nng lng phn mnh (V) 22 26

III.2.4. Cng thc tnh ton kt qu

Hm lng Ethoxyquin trong mu =m

VX

(ppb)

X: nng (ppb) c c t din tch peak mu vi phng trnh ng chun.

V: Th tch pha long (ml).

m: Khi lng mu ban u (g).

Gii hn pht hin

Gii hn pht hin (LOD)

T

CLOD Cmin3




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CCmin : Nng dung dch chun nh nht timvo my ng vi 3 T 10

N

STC : T l tn hiu (signal) trn nhiu (noise) ng vi CCmin.

Gii hn nh lng ca phng php

LOQ = 3LOD

III.2.5.

Kt qu kho st chnh xc ca phng php

Kt qu kho st ng ca phng php

Sau khi kho st 18 mu thm chun (M+C) 3 nng khc nhau (5, 10,

15ppb), mi nng c 6 mu, kt qu thu c nh sau:

Nn mu Tn muCspike

(ppb)

Crecovery

(ppb)

Hiu sut thu hi(%)

Tm

M + C1 5 3,45 63,04 - 76,24

M + C2 10 7,23 62,15 - 77,5

M + C3 15 10,90 71,28 - 73,88

Bng 4. Kt qu kho st ng ca phng php

Cspike: nng dung dch chun thm vo mu.

Crecovery: nng thu hi c saukhi phn tch (gi tr ghi trn bng 4 l

gi tr trung bnh ca 6 mu c cng nng ).

Hiu sut thu hi c gi tr nm trong khong thiu sut thp nht n

hiu sut cao nht ca 6 mu c cng nng .

Kt qu thu c hiu sut thu hi nm trong khong 60% - 115% (theo tiu

chun ca AOAC) , vy ng c th chp nhn c.

Kt qu kho st chmca phng php

Sau khi kho st 18 mu thm chun (M+C) 3 nng khc nhau (5, 10,

15ppb), mi nng c 6 mu, kt qu thu c nh sau:

Nn mu Tn muCspike

(ppb)

Crecovery

(ppb)

lch

chun SDRSD (%)

Tm

M + C1 5 3,45 0,26 7,44

M + C2 10 7,23 0,56 7,77

M + C3 15 10,90 0,14 1,29Bng 5. Kt qu kho st chm ca phng php




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Cspike: nng dung dch chun thm vo mu.

Crecovery: nng thu hi c saukhi phn tch (gi tr ghi trn bng 5

l gi tr trung bnh ca 6 mu c cng nng ).

Kt qu thu c RSD < 15% (theo tiu chun ca AOAC) , vy chm cth chp nhn c.

Kt lun

Kt qu kho st cho thy:

ng chun tuyn tnh trong khong nng kho st viR2= 0,9955.

ng v chm u nm trong khong chp nhn c theo tiu

chun ca AOAC.

T 2 yu t trn c th kt lun phng php s dng l ng tin cy.

IV.Thu mua mu

Mu c thu mua mt s ch ti thnh ph Cn Th: ch Xun Khnh, ch

An Lc, ch An Nghip, ch Bnh Thy, ch Hng Li, ch Ci Rng, ch Ph Th.

ChS mu thu mua

Ngy thu muaTm s Tm th

Xun KhnhQun Ninh Kiu 4 4 14/1/2013

An LcQun Ninh Kiu 4 4 14/1/2013

An NghipQun Ninh Kiu 4 4 14/1/2013

Bnh ThyQun Bnh Thy 4 4 14/1/2013

Hng LiQun Ninh Kiu 4 4 15/1/2013

Ci RngQun Ci Rng 4 4 15/1/2013

Ph ThQun Ci Rng 4 4 15/1/2013

Bng 6. S lng mu thu mua cc ch trn a bn thnh ph Cn Th

V. Kt qu phntch

Sau khi tin hnh thu mua 56 mu tm (gm 28 mu tm s v 28 mu tm th)

v x l theo qui trnhIII.2.2 thu c kt qu sau:




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Loi tmS mu pht hin d lng

S mu khngpht hin

Tng smuS mu c d

lng > MRLS mu c dlng < MRL

Tm s vtm th

12 10 34 56

T l (%) 21,43 17,86 60,71 100

Bng 7. Kt qu phn tchtng hpd lng cht chng oxy ha ethoxyqiun trn c

hai nn mu tm s v tm th

Tho lun

Kt qu phn tch c s mu pht hin d lng ethoxyquin l 22/56 mu

chim t l 39,29%. C 12/56 mu c d lng > MRL chim t l 21,43% v c 10/56

mu c d lng < MRL chim t l 17,86%. S mu khng pht hin d lng

ethoxyquin l 34/56 mu chim t l 60,71%.

V.1. Kt qu phn tch d lng cht chng oxy ha - ethoxyqiun trn nn

mu tm s


S mu khngpht hin

Tng smuS mu c d


Tm s 4 6 18 28

T l (%) 14,29 21,43 64,29 100

Bng 8. Kt qu phn tch d lng cht chngoxy ha ethoxyqiun trn nn mu

tm s




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Bng 9. D lng ca mt s mu nhim ethoxyquin trn nn mu tm s

Tho lun

Kt qu phn tch c 10/28 mu pht hin d lng ethoxyquinchim 35,71%.

Trong c 4 mu c d lng vt mc cho phpchim t l 14,29% v 6 mu c

d lng thp hn mc cho phpchim t l 21,43%. Cn li 18 mu khng pht hin

d lng ethoxyquinchim t l 64,29%.

Cc mu nhim ethoxyquin c hm lng tng i cao so vi MRL (10ppb)

m Nht Bn cho php i vi tm Vit Nam. Mu c hm lng ethoxyquin cao

nht l muSUAL4 gp khong 16 ln so vi MRL.

V.2. Kt qu phn tch d lng cht chng oxy ha ethoxyqiun trn nn

mu tm th


S mu khngpht hin

Tng smuS mu c d


Tm s 8 4 16 28

T l (%) 28,57 14,29 57,14 100

Bng 10. Kt qu phn tch d lng cht chng oxy ha ethoxyqiun trn nn mutm th

TT Tn mu a im ly muD lng

(ppb)MRL (ppb)

1 SUXH 2 Ch Xun Khnh 8,59

10

2 SUXH 3 Ch Xun Khnh 7,283 SUHL 2 Ch Hng Li 16,93

4 SUHL 3 Ch Hng Li 89,95

5 SUAL 2 Ch An Lc 9,52



8 SUAN 2 Ch An Nghip 23,31

9 SUBT 2 Ch Bnh Thy 4,53

10 SUBT 3 Ch Bnh Thy 4,70




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Bng 11. Kt qu phn tch d lng cht chng oxy ha ethoxyqiun trn nn

mu tm th

Tho lunKt qu phn tch c 12/28 (42,66%) mu pht hin d lng ethoxyquin.

Trong c 8 mu c d lng vt mc cho phpchim t l 28,57% v 4 mu c

d lng thp hn mc cho php chim t l14,29 %. Cn li 16/28 (57,14%) mu

khng pht hin d lng ethoxyquin.

Cng tng t nh trn nn mu tm s, cc mu nhim ethoxyquin trn nn

mu tm th c hm lng tng i cao so vi MRL (10ppb)m Nht Bn cho

php i vi tm Vit Nam. Mu c hm lng ethoxyquin cao nht l muTHEXH1

gp khong 15,3 ln so vi MRL.

TT Tn mu a im ly muD lng

(ppb)MRL (ppb)

1 THEXH 1 Ch Xun Khnh 153,34

10

2 THEXH 3 Ch Xun Khnh 37,21

3 THEAL 2 Ch An Lc 48,71

4 THEAL 3 Ch An Lc 6,92

5 THEAN 1 Ch An Nghip 3,74

6 THEAN 2 Ch AnNghip 7,94

7 THEBT 1 Ch Bnh Thy 18,55

8 THEBT 3 Ch Bnh Thy 59,47

9 THEBT 4 Ch Bnh Thy 22,1610 THECR 2 Ch Ci Rng 5,88

11 THEPT 2 Ch Ph Th 112,87

12 THEPT 4 Ch Ph Th 31,90




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Phn 3:KT LUN V NGH

I. KT LUNSau thi gian nghin cu, ti t c mc ch ra:

Xy dng cc thng s, chn lc iu kin ti u cho qu trnh thc nghim trn

my sc k lng ghp khi ph c th phn tch cht chng oxy ha

ethoxyquin trn nn mu tm (tm s v tm th). Kt qu kho st ph hp vi

cc tiu chun phn tch ca Hip hi cc nh phn tch Ha hc (AOAC):

+ Gii hn pht hin LOD = 3ppb.

+ Xy dng ng chun tuyn tnh trong khong nng chn t 1

16ppb.+ Hiu sut thuhi nm trong khong t 60 115%.

Thu mua 56 mu tm (gm 28 mu tm s v 28 mu tm th) mt s ch

thuc a bn thnh phCn Th v phn tch bng phng php sc k lng

ghp u dkhi phba t cc(LC/MS/MS) vi cc kt qu nh sau:

+

Kt quphn tch c 22/56 mu pht hin d lng ethoxyquinchim t l

39,29%, trong c 12/56 mu c d lng cao hn MRLv 12/56 mu c

d lng thp hn MRL, s mu khng pht hin d lng ethoxyquin l

34/56 mu chim t l 60,71%.

+

Trn nn mu tm s phn tch c 10/28 mu pht hin d lng

ethoxyquin vi nng dao ng t 3,05ppb n 159,03ppb. Trong c

4/28 mu c d lng cao hn MRL v 6/28 mu c d lng thp hn

MRL. Cn li 18/28 mu khng pht hin d lng ethoxyquin.

+ Trn nn mu tm th phn tch c 12/28 mu pht hin d lng

ethoxyquin vi nng dao ng t 3,74ppb n 153,34ppb. Trong c

8/28 mu c d lng cao hn MRLv 4/28 mu c d lng thp hn.

Cn li 16/28 mu khng pht hin d lng ethoxyquin.

T kt qu thu c, c th kt lun:

T l nhim ethoxyquin trn nn mu tm th v tm s l tng ng nhau.

T l mu c d lng ethoxyquin vt mc cho php vn cn cao.

D lng ethoxyquin trong tm vn cn rt cao so vi gii hn cho php mNht Bn a ra. C nhng mu d lng ethoxyquin ln n 159,03ppb,




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trong khi gii hn cho php m Nht Bn ra i vi tm Vit Nam l

10ppb. Nhn chung, d lng ethoxyquin cn tn d trong cc sn phm tm vn

cn rt cao.

Vic s dng ethoxyquin nh mt cht chng oxy ha vn cn rt ph bin.II. NGH

Thc t, cc sn phm tm khi c xut khu sang th trng nc ngoi nu

khng t chun cht lng th cc s b tr v nc, cc sn phmny s c mang

v cc a phng tiu th v nhng ngi tiu th cc sn phm ny khng ai khc

ngoi ngi dn. Tuy nhin, khu kim tra cht lng sn phm cc a phng cn

rt hn ch. Khi ngi dn n phi nhng sn phm tm b nhim cc cht bo qun c

hm lng vt mc cho php th c th dn n tnh trng ng c thc phm, vic

tm hiu nguyn nhn gy ng c s gp nhiu kh khn. y l mt vn ln gy

nhiu bc xc v cn c quan tm. Xut pht t thc trng ny, chng ti mon g

mun:

ti s tip tc nghin cu vi s lng mu nhiu hn, trn nhiu nn mu

khc nhau (tm nguyn liu v tm thnh phm) cc a bn rng hn c kt

qu tt hn. Trn c s thng tin cho cc doanh nghip cng nh cc n v

nui tm v kt qu nghin cu nhm nng cao cht lng ca sn phm th

trng trong nc v c nc ngoi.

Cc c quan chc nng cn c nhng nghin cu k hn v nh hng ca

ethoxyquin n con ngi ngi tiu dng c th an tm s sng cc loi thc

phm ch bin t tmv cc nh kinh doanh tm trnh c nhng thit hi khi

xut khu tm sang nc ngoi.

Cc c quan chc nng cn t chc nhng bui tuyn truyn v nh hng cacht bo qun n sc khecon nginhm gip ngi dn c th phng trnh

b ng c thc phm v bo v sc khe tt hn.




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PH LCPH LC 1: SC K CC DUNG DCH CHUN V MT S MU

TM

Ph lc 1.1: Sc k mu trng




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Ph lc 1.2: Sc k dung dch chun 1ppb




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Ph lc 1.7: Sc k mu cng chun 10ppb




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Ph lc 1.8: Sc k mu khng pht hinethoxyquin




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45

Ph lc 1.9: Sc k mu tm spht hin ethoxyquin vi hm lng4,7ppb




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Ph lc 1.10: Sc k mu tm s pht hin ethoxyquin vi hm lng8,59ppb




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47

Ph lc 1.11: Sc k mu tm s pht hin ethoxyquin vi hm lng16,37ppb




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Ph lc 1.12: Sc k mu tm th pht hin ethoxyquin vi hm lng18,55ppb




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Ph lc 1.13: Sc k mu tm th pht hin ethoxyquin vi hm lng23,31ppb




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50

Ph lc 1.14:Sc k mu tm s pht hin ethoxyquin vi hm lng89,95ppb




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Ph lc 1.15:Sc k mu tm th pht hin ethoxyquin vi hm lng153,34ppb




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PH LC 2: MT S THIT B THC HIN TI

H thng my HPLC

My li tm HERMLE Z36HK Cn phn tch Sartorious ED 224S




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Bn siu m c gia nhit ELMAMy lc

My vortex




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TI LIU THAM KHO

Ti liu ting Vit[1] inh ng Huy (2009), Nghin cu nh lng c t sinh hc bin ASP

trong thy sn v sn phm thy sn bng phng php sc k lng ghpkhi ph TANDEM LC-MS/MS, Lun vn Thc s khoa hc, Trng i hc

Khoa hc T nhin.

[2] Nguyn Kim Phi Phng (2007), Phng php c lp hp cht hu c, tr.

409450, NXB i Hc Quc Gia TP H Ch Minh.

[3] Nguyn Kim Phi Phng (2004), Khi ph, tr. 409 450, NXB i Hc

Quc Gia TP H Ch Minh.

[4]

Nguyn Th Phng Thu (2012), Kho st d lng mt s thuc bo vthc vt nhm pyrethroid trn tri cy thnh ph Cn Th, Lun vn tt

nghip, i hc Cn Th.

[5] Nguyn Th Thanh Nga (2009), Nghin cu qui trnh xc nh d lng

ciprofloxacin v enprofloxacin trong thc phm bng

Documents

Khảo sát hàm lượng chất chống Oxy hóa - Ethoxyquin có trong tôm ở một số chợ trên địa bàn Thành phố Cần Thơ