PHAN TCH VA KHAC PHUC

NHNG S CO THNG GAP

TRONG S DUNG THIET B

QUANG HOC

2.1.1. Cac thanh phan

2.1.1.1. en nguon

2.1.1.2. Bo phan tao anh sang n sac

2.1.1.3. Cuvett o va ngan cha cuvett

2.1.1.4. Detector

2.1.1.5. He thong quang hoc

2.1.2. May quang pho thong thng

2.1.3. May quang pho diode array

2.1. S khi v nguyn l hot ng ca h thng my o UV-Vis

2.1.4. Cau hnh

2.1.4.1. Kieu mot chum tia

2.1.4.2. Kieu hai chum tia

2.1.4.3. Kieu Split-beam

2.1.4.4. Kieu Dual-wavelength

2.2. Cc s c thng gp v cch khc phc

2.3. Hieu chuan van hanh

2.1. S o khoi va nguyen ly

hoat ong may quang pho t

ngoai kha kien UV-Vis

Double-beam UV-Vis. spectrophotometer

CAC THANH PHAN CHNH CUA MAY UV-Vis

en nguon (1)

Bo phan tao anh sang n sac (2)

Cong o va ngan cha cong o (3)

Detector (4)

He thong quang hoc (5)

EN NGUON (LAMP) (1)

AC IEM CUA NGUON SANG LY TNG

Cng o sang hau nh khong thay oi va

u manh moi bc song trong vung t

ngoai kha kien.

o nhieu thap

Can dung on ap e on nh cng o bc xa

cua en nguon

Cho cc ai bc xa hu ch trong vung

kha kien (t 656,0 en 656,2 nm) c

dung e kiem tra o ung cua bc song

may quang pho.

Nhieu gay han che en hieu nang cua

may.

Thi gian ban huy (cng o en giam

ch con phan na so vi gia tr luc mi lap

at) xap x 1.000 gi.

10

l Ranges of Common Sources

EN DUNG CHO VUNG KHA KIEN

en Tungsten

Si ot lam bang wolfram. Chat lieu lam bong bang thuy tinh. Nhiet o si ot hoat

ong la 2.870 K.

en Tungsten/Halogen

Co mot lng nho iod ben trong vo en bang thach anh cha si ot wolfram.

Nhiet o si ot hoat ong gan 3.500 K.

S phan bo nang lng phu thuoc vao

nhiet o. vung kha kien, nang lng

en thay oi theo ien the hoat ong. Do

vay can thiet dung on ap.

ac iem

Cho cng o sang at yeu cau s dung

tren mot phan vung t ngoai va toan bo

vung kha kien (t 340 en 900 hay 1.100

nm).

o nhieu rat thap, rat t troi ng nen.

Thi gian s dung khoang 10.000 gi.

SO SANH EN TUNGSTEN VA EN

TUNGSTEN/HALOGEN

Tuoi tho cua en tungsten/halogen cao hn gap oi so vi en

tungsten.

en Tungsten, tungsten b thang hoa di tac dung cua nhiet o cao lam si

ot b mon dan theo thi gian va b t

e lai vet en tren au bong en.

Ket qua la tuoi tho en b giam.

en Tungsten-Halogen, iod

phan ng vi hi tungsten b thang

hoa di tac dung cua nhiet o cao

tao thanh hp chat WI2.

Chat nay (WI2) ngng tu tren

si ot giai phong wolfram, nen

si ot khong b mon, gia tang tuoi

tho en.

EN XENON

Tao ra nhng bc xa co cng o ln bang cach cho dong ien iqua bau kh

xenon.

Cho pho lien tuc t 250 - 600 nm.

ac iem

Cho cng o sang at yeu cau

lien tuc trong vung UV-Vis.

Thng dung trong nhng ng dung

nh o t le tan xa hay quang

pho huynh quang can cng o cao.

BO PHAN TAO ANH SANG N SAC

(MONOCHROMATOR) (2)

Cac thanh phan quang hoc cua mot

bo phan tao anh sang n sac bao

gom: khe vao (1), knh chuan truc (2),

bo phan tan sac gom lang knh hay

cach t (3), mat phang hoi tu (4), khe

ra (5).

Tao ra anh sang vi cac bc song

khac nhau c tan sac nhng goc

khac nhau.

Bo phan nay dung e chon t

nguon sang mot anh sang n sac

co bc song mong muon i qua

mot khe ra thch hp.

Bo phan tan sac: co 2 loai thong

dung la lang knh va cach t.

PRISMS

20 6/29/2014

1 2 3

: angle of deviation

LANG KNH (PRISM)

ac iem

Tao ra anh sang nhieu mau sac nh

cau vong t anh sang mat tri.

Cau tao n gian va re tien nhng

cho goc tan xa khong tuyen tnh va

phu thuoc nhiet o.

Nhc iem cua lang knh

Pho cho bi lang knh khong tuyen tnh

ve bc song.

Lang knh hap thu mot phan nang lng

anh sang khi i qua no.

Goc tan xa phu thuoc nhiet o.

Phai tao ra c che quay lang knh tng

oi phc tap e co the kiem tra bc

song t thang o.

m = d sin

CACH T (GRATING)

S tan sac cua bc xa t ngoai kha kien co the c tao ra bang cach

hng mot chum tia a sac cho i

qua cach t dan truyen hoac ve pha

cach t phan xa (dung nhieu hn

trong thc te).

Cach t phan xa la mot ban thuy tinh

ma nhom. Tren be mat ma nhom nay

co nhng ranh song song va gan ke

nhau.

Phan b rach khong phan chieu anh sang, phan con lai ong vai tro mot

gng phang gom nhieu gng rieng

biet nhau.

Anh sang chieu ti phan ma nhom

khong b rach nay se b phan xa tr lai

theo nhng goc khac nhau tuy thuoc vao

bc song cua chung.

Cac tia phan xa se giao thoa vi nhau

tao nen van nhieu xa co bc song khac

nhau.

Khi quay cach t, ta thu c khe ra cac van co bc song khac

nhau.

Cach t phan xa anh sang nhng

bac khac nhau nen phai dung knh

loc e ch cho anh sang cua bac

anh sang phan xa mong muon en

au do.

CACH T LOM (CONCAVE GRATINGS)

c tao thanh tren be mat lom

Cho phep thiet ke mot bo tao anh sang

n sac ma khong can bo phan chuan

truc phu tr, gng hoi tu v be mat

lom co the phan tan roi tap trung

bc xa khe ra.

Loai nay co u iem la gia re, s giam

thieu cac be mat quang hoc lam gia

tang mc nang lng cua bo tao anh

sang n sac cha cach t lom.

HOLOGRAPHIC GRATINGS Ky thuat quang hoc tao cach t tren

be mat thuy tinh phang hay lom bang

tia laser.

Ky thuat nay cho phep tao cac ranh

ong eu ve kch thc va hnh dang.

Cach t loai nay cho cac pho khong

co anh sang lac va nhieu (ghost).

Tao thanh bang cach chieu 2 chum tia laser giong nhau t 1 goc thch hp

len mot be mat thuy tinh co tam chat

can quang.

Van giao thoa tao thanh t 2 chum tia

tren tang nhay chat can quang lam cho

no tan ra e lai mot cau truc co khac

vach

Sau o phan con lai c ma nhom

hoac nhng chat phan xa khac e tao

thanh cach t phan xa

U IEM CUA CACH T SO VI LANG KNH

Cho o phan giai tot hn

Cho s tan sac tuyen tnh

o rong cua giai pho la hang tnh

C che chon bc song n gian hn

CONG O VA NGAN CHA CONG O

(CELL & CELL HOLDER) (3)

CONG O

c lam bang chat lieu sao cho

anh sang trong vung o phai truyen

qua (trong thc te cac loai cong o co

o truyen toi a la khoang 90% moi

bc song trong vung UV-Vis)

Trong vung t ngoai (di 350 nm)

dung dung coc lam bang thach anh

hay silica (silic dioxid) nong chay.

Trong vung kha kien dung dung

cong lam bang thuy tinh silicat

hoac bang chat deo (nha acrilic).

Quang lo cong o thong thng

nhat la 1 cm.

Ngoai ra con co cac cong o co

quang lo t 0,1 en 10 cm dung cho

cac nong o thch hp ma khong

can pha loang tiep theo.

KIEU CONG O TIEU CHUAN

Pho bien nhat la loai cong o hnh khoi ch nhat. Quang lo coc o thong

thng nhat la 1 cm.

Ngoai ra con co cac cong o co quang lo t 0,1 en 10 cm e dung

cho cac nong o thch hp ma khong

can pha loang tiep theo.

Neu the tch mau co gii han th dung cong o co ca so.

MOT SO KIEU CONG O AC BIET

Microcell

La loai cong o co ca so rat nho

(co mat cat 2 x 2,5 mm). Ch can

lng mau xap x 60 l e o.

Ultra-microcell

La loai dung cu o mi thiet ke e

o the tch mau c microlit (2-5l) bao gom mot bo phan tiep hp va

mot ong mao quan bang silica

nong chay quang lo ngan dung

mot lan.

Cho trc tiep mau o vao ong mao quan, sau o cai vao bo phan

tiep hp. Quang lo giam cho phep

o cac mau co nong o cao ma

khong can pha loang. Ap dung e

o nong o va o tinh khiet cua

AND va nong o protein.

Coc o kieu dong chay lien tuc

Dung trong trng hp t ong

hoa nh trong may quang pho

ghep noi vi may o o hoa tan.

NGAN CHA CONG O (CELL HOLDER)

Ngan cha cong o e o o uc

(Turbidity Cell Holder)

Ngan cha cong o c dch chuyen

ra xa detector so vi v tr bnh thng

va mot khe at gia mau va detector.

Khe nay ch cho phep anh sang lo i

qua mau ma khong cho anh sang tan

xa en en detector.

Micro-Auto 12 Cell Holder

La loai ngan cha cong o dung

trong sinh hoa e phan tch ong hoc

enzym. Bao gom cac ngan cha cong

o co the tch toi thieu 100 l va bo

phan ieu hoa nhiet o bang dong

nc hoac kieu Peltier.

Water circulated Cell Holder

La loai ngan cha cong o duy tr

c nhiet o bang mot dong nc

luan chuyen lay t may ieu nhiet

(Thermostat). Dung trong phan tch

enzym.

Micro-Auto 6 Tm

Cell Holder

La loai ngan cha coc o dung trong

sinh hoa e xac nh tm

(thermal melting

point) cua AND. Bao gom mot bo phan

kiem soat nhiet o kieu Peltier, quat lam

nguoi ngan cha coc o bang khong kh,

bo phan lam sach hi ngng tu tren

thanh coc o dung kh nitrogen, hai ien

cc hieu nang cao Peltier, bo phan o

nhiet o bang cam bien nhiet.

DETECTOR (4)

La cac ong thuy tinh hoac silica c tao

chan khong vi cathod la kim loai kiem,

anod tch ien dng.

Khi anh sang chieu ti cathod, cac

electron c tach ra va i ti anod lam

cho the tang len t le vi cng o anh

sang.

o nhay pho cua cac te bao xac nh

bang chat lieu cathod, vi antimon/cesium

t 190 600 nm, vo oxid cesium/bac t 600 1000 nm.

Detector ong nhan quang

(Photomultiplier)

Nguyen tac hoat ong gan giong te bao

quang nhng co them bo khuech ai ben trong

lam cho loai nay co o nhay ln hn tren thang

pho rong hn.

Anh sang gay ra s bc xa photon t

photocathod, giong nh trong te bao quang

nhng anod c sap xep thanh day dynod co

the tang len khong ngng.

43 2- Photomultiplier tube (PMT)

Detector silicon diod (Silicon diode)

Co hieu nang cho toan bo thang o

rong, vng chac, o tho cao hn ong

nhan quang va khong tieu hao nhieu

ien nang.

Chuoi diod la mot tap hp cac detector

photodiod rieng biet xep at ke nhau

tren tinh the silicon tuyen tnh trong ma

tran tao nen.

Moi diod co mot tu ien va c noi

vi dong au ra bang mot cai ngat.

SiSi

SiSi

SiSi

SiSi

Al

p-type = mobile positive

charge resides in Si

crystal (+ hole rich)

SiSi

SiSi

SiSi

SiSi

P

n-type = mobile negative charge resides in Si crystal (e- rich)

3- Photodiode

3- Photodiode array

au tien tu ien c tch mot gia tr ien nhat nh.

Khi photon tham nhap vao silicon,

nhng phan mang ien tch t do tao

thanh e xa tu ien.

Tu ien lai c tch ien nhng

chu ky ac trng cho chu ky o oi vi

moi chu ky quet.

Lng ien can e nap cho tu ien t le vi so pho ton c phat hien bi moi

diod hay noi cach khac t le vi cng o

sang.

Pho hap thu thu c bang cach o

lng s thay oi cng o sang tren

toan khoang bc song. Thong thng

detector chuoi photodiod cha 1024

detector photodiod rieng biet.

HE THONG QUANG HOC

(OPTICAL SYSTEM) (5)

S dung cac thau knh hay gng lom e tap trung anh sang. Neu dung

loai knh thong thng co the b sai lac

ve mau sac.

Knh tieu sac ket hp nhieu loai knh

vi ch so khuc xa khac nhau khong

gay ra hien tng sai lac ve mau sac

nhng gia thanh cao.

Gng lom re hn knh tieu sac va cung khong b sai lac ve mau sac

nhng be mat nhom de b an mon lam

giam hieu nang.

Tren moi be mat quang hoc ke ca

giao dien gia cac thanh phan cua knh

tieu sac, 5 10 % anh sang the hien qua s hap thu hay phan chieu.

Mot may quang pho ly tng phai

thiet ke vi be mat quang hoc toi thieu.

MAY QUANG PHO THONG THNG

Anh sang a sac t en nguon tap trung khe vao cua bo tao anh sang

n sac cho truyen qua mot cach chon

loc mot day anh sang hep.

Day anh sang nay i qua mau, lo ra

va en detector.

o hap thu cua mau la hieu gia

cng o anh sang ti detector cua

mau trang va mau th.

May loai nay thch hp e o o hap thu mot bc song tren pho

nhng khong thch hp lam khi o

nhng chat khac nhau nhng bc

song khac nhau hoac khi lay pho

cua mot chat.

e lam c ieu nay, bo tao anh

sang n sac phai xoay mot cach c

hoc gay ra sai so do o tai lap. Qua

trnh thu nhan d lieu can co thi

gian.

CAU HNH

Kieu mot chum tia

Co the la loai may quang pho

thong thng hoac may quang pho

day diode.

He thong quang hoc n gian nen

co o nhay cao va gia thanh ha.

May quang pho oi chng do Vien tieu chuan va ky thuat quoc

gia Hoa ky va phong th nghiem

vat ly quoc gia Anh quoc s

dung la loai may mot chum tia.

May quang pho day diode ac

biet thch hp cho cau hnh mot

chum tia v thu c pho rat

nhanh va khoang thi gian o

gia mau trang va mau th b

giam en mc toi thieu.

Kieu hai chum tia

Chum tia i t en nguon ti bo tao anh sang n sac c tach ra

thanh hai chum tia n sac bang

nhau do mot bo chan sang t ong

xoay vai giay mot phut (chopper),

mot chieu ti mau o, mot chieu ti

mau oi chieu

Diagram of a double-beam UV-Vis.

spectrophotometer

Kieu split-beam

Giong vi loai may 2 chum tia nhng dung bo tach chum tia (beam splitter)

thay v chopper e cho anh sang i

qua mau trang va mau th ong thi

e en 2 detector rieng biet giong

nhau.

Vi cau hnh nay, mau trang va mau

th c o ong thi. He thong

quang hoc cung n gian hn may 2

chum tia thc thu.

Nhc iem la hai detector co the

khong hoan toan ong nhat nhau.

Diagram of a spilitter-beam UV-Vis. spectrophotometer

Kieu dual-wavelength

Cau hnh nay cho phep o 2 bc song ong thi nh khi nghien cu 2

phan ng xay ra ong thi ben trong

mau.

Bo tao anh sang n sac cha 2 bo

phan tan sac.

May loai nay at hn may quang

pho thong dung va c dan thay the

bang may quang pho diode array co

the ghi pho ong thi nhieu bc

song khac nhau.

MAY QUANG PHO DIODE ARRAY

Anh sang a sac t en nguon i qua mau roi tap trung khe vao

cua bo tao anh sang a sac sau o

b tan sac tren day diode, moi

diode o mot day hep cua ca pho.

Kch thc cua diode va khe vao

cua bo tao anh sang a sac co lien

he en o rong day cua anh sang

phat hien.

61 6/29/2014

3- Photodiode array

Moi diode thc hien chc nang nh mot khe ra cua bo tao anh sang n

sac.

e giam thieu phan ng quang hoa,

may co ca chap e chan anh sang

t en nguon cho ti tien hanh o

mau.

May loai nay cho phep thu nhan d

lieu rat nhanh, o tai lap bc song

rat tot va o tin cay rat cao.

u iem

Ghi pho nhanh

Dung e nghien cu ong hoc

nh tnh va nh lng cac thanh

phan tach ra t cot sac ky

Nhc iem

Nang suat phan giai kem (1-2nm)

Gia thanh cao

2.2. CAC S CO THNG GAP

VA BIEN PHAP KHAC PHUC

EN KHONG CHAY KHI M NUT

POWER

Nguyen nhan

1a. Day nguon khong

noi vi may

1b. No cau ch nut

power

1c. Chay en nguon

1d. Mach ien b hong

1e. The nguon thap

Khac phuc

1a. Kiem tra day

nguon

1b. Thay cau ch nut

power

1c. Thay en

1d. Goi chuyen vien

bao tr

1e. Dung on ap

GIA TR O HAP THU CAO BAT THNG

VA KHONG TR VE 0 KHI NHAN PHM

AUTO ZERO

Nguyen nhan

Mot trong 2 hoac

ca 2 en nguon b

chay hoac khong

m

Khac phuc

M en len. Thay en

O HAP THU DAO ONG MANH

Nguyen nhan

3a. Chum tia oi

chieu b chan

3b. en tat hoac

b chay

Khac phuc

3a. Kiem trang

i cua chum tia

3b. Kiem tra nut bat

en va tnh trang

en

O PHANG NG NEN NAM NGOAI

GII HAN CHO PHEP

Nguyen nhan

Chum tia i qua

mau b chan mot

phan

Khac phuc

Don sach vung

chum tia i qua

mau va tien hanh

hieu chnh ng

nen

BC SONG HIEU CHNH NAM NGOAI

GII HAN CHO PHEP

Nguyen nhan

H hong ve c

hay ve ien

Khac phuc

Goi chuyen vien

bao tr

NHIEU NG NEN LN BAT THNG

Nguyen nhan

6a. o nhay detector kem

6b. Mot trong nhng bo phan quang hoc sau ay b

h hong:

Bo phan chuyen oi

nguon sang

Khe sang

Knh loc

Khac phuc

6a. Goi chuyen

vien bao tr

6b. Goi chuyen

vien bao tr

NHIEU NG NEN LN BAT THNG

Nguyen nhan

6c. en nguon a

het han s dung

6d. ien the cung

cap cho thiet b

thap hn quy nh

6e. Nhieu co nguon

goc ngoai lai

Khac phuc

6c. Thay en nguon

6d. S dung on ap

6e. at thiet b xa

cac trng ien t

hoac cac nguon

gay rung lac

NHIEU NG NEN LN BAT THNG

Nguyen nhan

6f. Thiet b khong

noi at

6g. o rong khe

sang nho

Khac phuc

6f. Noi at cho

thiet b

6g. Tang gia tr o

rong khe sang

O LECH D LIEU LN

KHONG CHAP NHAN C

Nguyen nhan

7a. en nguon b

yeu

7b. ng i cua

chum tia b anh

hng do dau van

tay hay bui

7c. Cong o hay ca so b ban

Khac phuc

7a. Thay en nguon

7b. Ra cong o

hay/va ca so

7c. Ra cong o hay/va ca so

MAY KHONG OC C TAT CA CAC

NH THEO QUY NH

Th du: Rifampicin co 4 cc ai hap thu

237, 254, 334 va 475nm. May khong ghi c

nh 237nm

Nguyen nhan

at o rong khe

sang (slit width)

khong phu hp

Khac phuc

Giam o rong khe

sang

O HAP THU DAO ONG MANH

Nguyen nhan

Dung cong o

thuy tinh e o

mau bc song

t ngoai

Khac phuc

Thay bang cong

o thach anh

O HAP THU GIAM DAN

Nguyen nhan

Dung moi b boc

hi

Bot kh hien

dien tren thanh

cong o khi cho

dung dch vao

Khac phuc

Dung cong o

co nap ay

Lam ay cong

bang pipet

O HAP THU THAY OI ANG KE

GIA CAC LAN O

Nguyen nhan

Dung cac cong o co o thau

quang khac nhau

Khong nh hang cong o

Khac phuc

Dung mot cong o e o cac mau

S dung cong vi cung mot mat

quay ve pha anh

sang

NH HAP THU B LECH VE PHA

BC SONG NGAN

Nguyen nhan

Hien tng

Tracking

(Tracking error)

do quet pho toc

o qua nhanh oi

vi may hai chum

tia

Khac phuc

Giam toc o

quet pho

Ghi pho chuan

trong cung ieu

kien

NH HAP THU B THAY OI SO VI

GIA TR QUY NH

Nguyen nhan

Dung moi s dung

khong chuyen

dung cho quang

pho

Dung moi co lan

nc

Khac phuc

Dung loai dung

moi thch hp

2.3 Hieu chuan va van

hanh may quang pho UV-

Vis

Hieu chuan

Xac nh o on nh, o ung, o chnh xac cua may. Kiem tra tnh trang hoat

ong cua may

Phat hien nhng khiem khuyet cua thiet b

Cung cap cac d lieu cho ngi bao tr e xac nh nhng hong hoc cua thiet b

nham ho tr trong sa cha

NOI DUNG

Kiem tra o phang ng nen (check of

baseline flatness)

Tren toan thang bc song, o thang giang (Fluctuation) cua

ng nen so vi khong kh phai

nam trong khoang qui nh cua

bang thong so ky thuat.

Th du

- May Hitachi U3210 co o thang giang

trong khoang 0,001Abs

- May Hitachi U2010 co o thang giang

trong khoang 0,002 Abs (200-950nm)

- May Hitachi U3000 co o thang giang

trong khoang 0,001Abs

- May Ultrospec III co o thang giang trong

khoang 0,002 Abs

Cong o (cells or cuves)

Thng dung cac cong o tieu chuan

Cac cong o phai am bao cac yeu cau sau:

Phan be mat hng chum tia va cho

chum tia i qua phai that phang, nhan

va song song vi nhau.

Hai ban anh sang ti vi anh sang i

qua phai song song vi nhau.

Quang lo trong cong o phai am bao gia

tr danh nh

Cong o thng c lam bang:

Thach anh (Quartz) cho vung o t

ngoai va kha kien

Thuy tinh cho vung o kha kien

Yeu cau cac cong o phai cho o hap

thu hay o thau quang luon luon bang

nhau khi cha cung mot dung moi hay

cung mot dung dch o trong cong. Cac

cong o co be day 10 mm co dung sai cho

phep ve o dai quang trnh la 0,005 cm

hay 0,05/10 = 0,005 = 5o/oo

Kiem tra bc song (control of wavelengths)

May phai am bao o ung cua bc

song (wavelength accuracy) theo ch tieu

ky thuat cua may do nha san xuat e ra

va phu hp vi yeu cau k thut ( 1nm t

200 - 400nm; 3nm t 400 - 700nm).

oi vi may quang pho UV-Vis the he

mi, en D2 c s dung nh la mot

nguon sang tao mot vach sang bc

song 656,1 nm e kiem tra o ung cua

bc song (656,4 - 655,8 nm).

oi vi ngi hieu chuan may th s dung

knh chuan holmium oxide hay dung dch

holmium perchlorat e kiem tra o ung cua

bc song.

Trong trng hp may o iem va khong

co chc nang quet pho, tien hanh o o hap

thu tai cac iem xung quanh cac cc ai e

kiem tra.

Kiem tra o hap thu (control of absorbances )

Kiem tra o hap thu cho biet o ung cua

may (Photometric Accuracy).

May phai cho cac thong so ap ng vi cac

thong so ky thuat e ra cho moi may va yeu

cau k thut.

Vi may at c o ung theo qui nh cho

phep co the thc hien phep o tuyet oi.

Dung dung dch kali dicromat. Gii han hap

thu la 0, 01 AU

Ghi pho cua dung dch toluen (TT) trong

hexan (TT) 0,02 % (tt/tt). Gia tr toi thieu cua

ty so gia o hap thu cc ai 269 nm va o

hap thu cc tieu 266 nm phai ln hn 1,5

Ghi chu: Theo BP 2005, ch tieu nay khong bat buoc.

o phan giai cho phan tch nh tnh (resolution)

ao ham bac hai (second derivative)

Vi may cho phep thc hien cac bien

oi t pho thong thng sang pho ao

ham bac mot, bac hai hay bac cao hn

phai kiem tra moi tng quan gia ao

ham bac hai va nong o cua chat can

khao sat. Moi tng quan nay phai tuyen

tnh.

May phai lay c ao ham bac hai theo

ung qui nh.

Gii han anh sang lac (limit of stray light)

Anh sang lac (stray light) la nguon goc gay

sai so chnh cho may nen c qui nh rat

chat che khi hieu chuan may.

Yeu cau khi o la tia chieu ti mau o phai

that s n sac.

Khi chum tia chieu ti bo tao anh sang n

sac e tao thanh cac tia n sac, co cac quang

sai nen dan en viec tao ra cac tia la i kem

vi tia n sac chieu ti mau do s cha hoan

hao cua s tan sac

Mau khong hap thu cac tia nay

Tiep theo cac tia nay lai chieu en detector,

lam giam o hap thu cua nh can khao sat nhat

la khi o vung gan 200 nm va dung dch co o

hap thu cao.

Anh sang lac cung gay ra s sai lech am cho

nh luat Lambert Beer khi o thang o co o

hap thu cao.

Anh sang lac cung tao ra khi buong o (sample

compartment) khong kn.

Yeu cau may phai cho gii han cua anh sang

lac trong pham vi cho phep.

Van hanh

May quang pho UV-Vis

o iem (nh lng)

Quet pho(nh tnh)

o ong hoc

o iem (nh lng)

Bat may, si am (warming up).

Chon bc song can o.

Cho chum sang i qua mau trang.

Hieu chnh cong o.

at mau vao khoang o.

oc gia tr o hap thu.

Cac iem can lu y

Lam ve sinh cong trc khi o.

Khong dung cong b nt hoac xc.

S dung cung mot cong cho chum

tia oi chieu.

Hng cung mot mat cua cong ve

pha anh sang.

Chat long trong cong ng mau th

va mau oi chieu eu phai khong co

bot kh va tieu phan.

Cac iem can lu y

Lau cong can than bang giay tham

mem hoac vai khong x.

Khong x tay vao be mat trong

suot cua cong o.

Dung moi s dung khong c co

o hap thu anh sang trong vung

bc song can o.

Cong mau th phai c ra t

nhat 3 lan bang dung dch mau th

trc khi o.

Cac iem can lu y

Kiem tra cong e am bao s khac

biet ve o hap thu khong phai do

cong b ban.

Khong o o hap thu khi co bot kh.

Khong s dung cloroform bc song di 245 nm.

Dung moi s dung phai lay t cung

mot chai.

Neu dung moi la nc, nen dung nc

mi cat.

Cac iem can lu y

Nen bao quan dung moi hu c

trong chai thuy tinh mau, khong

ng trong chai nha.

Oxy trong dung dch lam tang o

hap thu neu dung moi la con

bc song di 230 nm.

Cac hp chat cacbonat hap thu

manh bc song di 240 nm.

Can o nhanh va ay nap cong o.

Quet pho (nh tnh)

Tien hanh giong nh o iem.

bc song di 230 nm, o hap

thu nen di 0,7.

Nen quet pho UV t 370 nm en

bc song ngan nhat van cho ket

qua ung.

Can at ung o rong khe sang

e co o phan giai can thiet.

o ong hoc

Khao sat o ben cua mau va van toc cac phan ng thuy phan chat

nen do enzym xuc tac.

Tien hanh bc song xac nh.

Ghi lai s thay oi o hap thu theo thi gian.

EN DUNG CHO VUNG T NGOAI

en Deuterium

Deuterium b kch thch ien ap suat thap tao ra pho phat xa lien tuc trong

vung t ngoai

Bong en lam bang thach anh v thuy tinh hap thu manh anh sang vung

bc song di 350 nm

Cho cng o sang at yeu cau s dung lien tuc trong vung t ngoai (t

200 en 340 nm)