UNIVERSITY OF NAPOLI “FEDERICO II” Soil fertility … · 2018-07-30 · UNIVERSITY OF NAPOLI “FEDERICO II” AGRICULTURAL FACULTY. Soil Chemistry Department. Dr. Spaccini Soil

UNIVERSITY OF NAPOLI “FEDERICO II”

AGRICULTURAL FACULTY

Soil Chemistry Department

Dr. Spaccini

RiccardoSoil organic matter

Soil fertility

increase

or decr

ease

soil managem

ent Analyses:-

Chemical-physical soil properties

-

GasChromatografy-

Mass Spectrometry

-InfraredSpectroscopy-LiquidChromatografy

(HPSEC)-

Liquid state NMR

-

Solid state NMR

IREEA-Nanjing Agricultural University/ April 2008

Humic substances

accumulation

/stabilization

degradation

Molecular characterization of soil humic acids extracted after soil treatments with recycled organic biomass

• IR-DRIFT (Diffuse Reflectance Infrared Fourier Transform)

• Sequential extractions

• CPMAS-13C-NMR (CrossPolarizationMagicAngleSpinning-Nuclear Magnetic Resonance

Spectroscopic analyses:

off-line pyrolysis with TetraMethylAmmoniumHydroxide

(TMAH termochemolysis)

OBJECTIVE

GasCromatografy MassSpectrometry

molecular characterization


Infrared (IR)

Spectroscopymost spectroscopies techniques are based on the interaction between

electromagnetic wave and the unkown molecule

UV Vis Far IR

Infrared Near IR

Micro wave

λ

cm 10−5 10−2 10−110−4 10−3

energy

the most useful wavelenght

range

of electromagnetic radiation for infrared spectroscopy vary from 5 to 25 μm

25 μm5 μm

the energy associated with these wavelenght correspond to the molecular vibration of chemical bonds energy


C

Infrared Spectroscopy

wavelength λ (cm) frequency ν = c/ λ (Hz or s-1)

interaction with bond vibrational

energyC H

stretching

H

H

CHH

bending

in-planeout-of-plane

IR radiation

C Hsimmetrycal asymmetrical

C H

IR signals


Simmetrycal

stretching Asymmetrical stretching

In-plane bending

rocking scissoringOut-of-plane bending

wagging twistingIREEA-Nanjing Agricultural University/ April 2008


the IR spectra is a plot of transmittance

intensity against wavelenghts

in modern IR instrument

the

wavelenght

(λ) scale is replaced by wavenumber

units defined as the inverse of (λ) in cm-1

vanillinTran

smit t

ance

( %)

(μm)2.5 3.0 10 12 15 205.0 6.0 7.0 8.04.0

the wavenumbers

are directly proportional to vibration energy and allow a linear plotting in the cm-1

units scale

Energy

4000 3000 2000 1500 1000 500cm-1

the main advantage of Infrared Spectroscopy is that each fuctional group

has a unique frequency of absorption

the interaction between the incident IR ray and the chemical bonds produce typical absorption bands

each functional group has the same absorption frequency irrespective to the overall molecule and to other groups

however

in complex matrices such as SoilOrganicMaterial (SOM), humic substances, plant tissues etc. there is an overlapping

of

various functional groups

the interaction between vicinal functional groups (e.g.

hydrogen bonding) and the presence of inorganic impurities (salt ions) modify

the range of

various absorption frequencies


Bond /cm-1 attribution

3000-2850 stretching

saturated alkanes

1480-1350 bending

saturated alkanes3100-3000 stretching

unsaturated alkanes

or aromatic

1600-1500 bending unsaturated alkanes

or aromatic


alcohols and phenols

1420-1330 bending alcohols and phenols

1050-1300 stretching alcohols, phenols, ethers

1750-1710 stretching esters

1720-1680 stretching saturated/unsat. carboxylic acids


amide (amide I band)

1620-1550 bending

amide (amide I band)

R-C H

C H

R-C H

R-O H

C H

R-O H

R-C OR

R-C OR-C OR-C O

R-N H


H

20vanillinTr

ansm

it tan

ce ( %

)

4000 3000 2000 1500 1000 500cm-1

C H 3O

OHO M e

H

H


Electron Impact Mass Spectrometry (EI-MS)

the mass spectrometry analysis represent a powerful methods to identify the unknown organic compounds

the various techniques are based on the breaking of organic molecules in small charged fragments (ions); the detection and the analysis of various fragments (ions) allow the identification of

the

original organic compounds

Sample

Ion Source

Mass Analyzer

Detector

Data analysis

IREEA-Nanjing Agricultural University/ April 2008IREEA-Nanjing Agricultural University/ April 2008

In the Electron Impact MS the organic compound is introduced in the ion source

(under high vacuum) and

bombarded with an

high energy

electron beam (70 eV)

MGas Chromatograph

Electron beam (70 eV)

Ion source chamber Pressure = 10-5-10-7

torr

e-e-

e-e-

anode

M + e- M+

+ 2 e-

organic compound

the collision of electron beam transfer to the organic compound a large energy content thereby releasing one electron and producing a

positively charged radicalIREEA-Nanjing Agricultural University/ April 2008

the positive charged radical is highly unstable and it start immediately to loss the excess of energy by breaking down

(fragmentation) in small positively charged fragments with lower masses (positive mass fragments) of smaller molecular weight

the various

mass fragment (ions)

are then collected by electronic lens

and accelerating slit and pushed

in the

mass analyzer

which

provides a separation with respect to their molecular weight

m+m+

m+m+m+m+

m+m+

m+

m+m+

m+

m+

m+

the various fragments

are then collected by sampling

at regular interval

(usually

1 second) and forwarded to

the detector system

M+ fragmentation

Mass spectra IREEA-Nanjing Agricultural University/ April 2008

Ion source Electronic lens and accelerating slit

Mass analyzer

Collector and amplifier


Example of mass spectra: linear hydrocarbon /alkaneHentriacontane C31

H64 m.w. 436

Mass spectra

40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 4400

50

100

43

57

71

85

99113127

141 169 197 224 252 281 30933 337351365379393436

M+

Mass fragments

m+

57m+

85m+

127

the smaller masses are enrgetically stable and hence

are more abundant

the higher masses are energetically unstable

and

and have a short lifetime


the main advantage of EI-MS is that each compound classes have the same fragmentation pattern

the mass spectra are fingerprint of specific organic compounds classes


0

50

100

55 69

74

87

111129143

157 171 185 199213

225256

Fatty acids methyl ester

0

50

100

55

69

74

83

87

97111

129

143

157171

185 199213

269

283295

326

M+

M+

0

50

100

57

69

74

83

87

97111 129

143

157171

199213

227 241 255 269 283 297 311 325 339 353 367 381 409423

435

466

M+


the main advantage of EI-MS is that each compound classes have the same fragmentation pattern

the mass spectra are fingerprint of specific organic compounds classes

the mass spectra obtained from EI-MS technique greatly simplify the identification of unknown organic molecules

the modern MS spectrometer

are in fact associated with

software for

the interpretation of mass spectra

the software allow

a quick

comparison

between the mass spectra of unknown compound with the mass spectra of standard compounds of

library

database


Molecular characterization of soil humic acids extracted after soil treatments with recycled organic biomass

• IR-DRIFT (Diffuse Reflectance Infrared Fourier Transform)

Spectroscopic analyses:

off-line pyrolysis with TetraMethylAmmoniumHydroxide

(TMAH termochemolysis)

molecular characterization

OBJECTIVE

GasCromatografy MassSpectrometry


The recycled organic biomass (compost) was composed by the following organic residues

45% urban solid waste 40% plant residues (mais) 15% plant trimming

the recycled organic biomass was produced through a composting process made of a common oxidation period (active phase) of 30

days, followed a stabilization period (curing phase) of of

120

days

30 t ha-1

of recycled organic biomass were added to soil for 4 years

soil humic

acids were then extracted from soil at the following intervals

4th

year (HA 0 year) 5th

year (HA 1 year) 6th

(HA 2 year)


200 g soil

Soxhlet extraction with ethyl ether

1M

NaOH

+ 0.1M Na4

P2

O7 shaken

overnight

( 1 liter)

pelletssupernatant

centrifugation

7000 rpm

washing with deionized water

till pH7

filtration quartz filter 0.45 μ

purification with HF/HCl solution dialysis

pH 1 with HCl

Humic acid extraction

fulvic acids

humic acids


1448

b

4000 2800 2000 1600 1400 1000 450cm-1

υas

2923 2851

υs

O

OR-C-OH R-C

-OH

1690

υ

1319

υ

1547

N-H bammide

II

1366

OH

OR-C-O-

K+

1690

υ

IR-spectra HA 0 year

11601029

R-C-O-C-R

carbohydratesC H-(CH2

)n

-lipids

aromatics

1794

R-C-O-RO

υ

esters

H

HOH

H

OMe

υs

b


4000 3000 2000 1500 1000 450cm-1

IR spectra of soil Humic

acids

2 year

1 year

N-H

2923 2851

1794

1670

1547 1448

1366

13191029

11600 year

lipids-(CH2

)n

-

R-(COOH) R-C-O-C-R

aromatics

lipids carbohydrates

aromaticslipids

carbohydrates


IR results

•

the infrared spectra of humic

acid extracted after soil addition with organic fertilizer revealed a composition dominated by lipid compounds and carbohydrates with

aromatic and peptidic

moieties

•

after one

year

the

spectroscopy

data suggested

a variation

in the humic acid composition represented by a large loss of alkyl components and a significant decrease of biolable compounds such as peptidic material

•

after two year

the IR spectra of soil humic acid was characterized by a decrease

of carbohydrates content. The final

composition

of humic acids revealed a prevalence of stable components represented by residual alkyl chains, aromatic compounds, ester and fatty acids and carbohydrates


Pirolysis-TMAH

(termochemolysis)

• thermochemolysis technique has been increasingly used in the last 20 years for the analysis of complex organic matter matrices such as humic substances, SOM, plant tissues etc.

• the breakdown of covalent bonds simplify the organic materials releasing low molecular weight components that are hence amenable for the Gas Chromatographic Mass Spectrometry analysis

• this technique is based on the contemporaneous application of high temperature (400-700 °C), and alkylating reagents (TMAH), under inert gas atmosphere (He2 ), for the breakdown of the covalent bonds that link together the organic matter components (C-C bonds, ester bonds, ether bonds)


400°C 30m

1 g

Humic Acids+

1 ml TMAH (25% CH3

OH)

He (50-100 ml/min

GC-MS

chloroform kept in ice/salt bath

5 minutes dry with nitrogen flow


Tetra Metil

Ammonum

Hydroxide

(TMAH) CH3 OH-

ROH

+ RCOO-

RO-

(CH3

)4

N+

+ H2

O

ROH + (CH3

)4

N+

OH- RCOO-

+ (CH3

)4

N+

RCOO-

(CH3

)4

N+

CH3

CH3

CH3N+

(da Challinor 2001 JAAP Vol. 61 )

GC-MS

R-COOR

+ (CH3

)4

N+

OH-Long chain

ester

(CH3

)3

N + RO CH3

Methyl ether

RCOOCH3

+ (CH3

)3

N

Methyl ester


TMAH thermochemolysis

OMeMeO

HH

OCH2OH

HH

OHH

OHOHH H

OO

CH2OH

HH

HOH

OH

H H

OCH2OH

HO

H

HOH

OH

H H

OO

CH2OH

HH

HOH

OH

H H

OH

O

OMeOR

MeO

HH

C=O

OR

OO

C=O

C=O

RO

O

HO

HO

HO

HORO HHO

C

ORO

polysaccharide

bio-polyester

ligninIREEA-Nanjing Agricultural University/ April 2008

O

OCH3

O

OCH2O CH3

HH

OCH3HOCH3

OCH3

H H

OCH3

O

OMeOCH3

MeO

HH

CH3

CH3

O

CH3

O

O C=OO

OO

CH3 CH3

CH3

OCH2O CH3

HH

OCH3HOCH3

OCH3

H H

O

OCH2O CH3

HH

HOCH3

OCH3

H H

OCH3


CH3

CH3O

GC-MS

11.0 16.0 21.0 26.0 31.0 36.0 41.0 46.0 51.0 56.0 61.0

C16

, 9/1

0-16

diC

H3O

, fam

eC

16, 9

-10

diC

H3O

, fam

e

C18

, 9,1

0,18

triC

H3O

, fam

e

P2G1

P4

P6S1

S6

S14G14

/15 C18

:1, ?

CH

3O, f

ame

G6

S4G4

C9

dioi

c

C8

dioi

c

C16

, tri

CH

3O, f

ame

C17

, iso

/ant

eiso

, fam

e

C29

C18

:1,

dioi

cac

id d

im.e

.

P18

C31

C33

C6

dioi

c

C16 C

18:1

11.0 16.0 21.0 26.0 31.0 36.0 41.0 46.0 51.0 56.0 61.0

C16

, 9/1

0-16

diC

H3O

, fam

eC

16, 9

-10

diC

H3O

, fam

e

C18

, 9,1

0,18

triC

H3O

, fam

e

P2G1

P4

P6S1

S6

S14G14

/15 C18

:1, ?

CH

3O, f

ame

G6

S4G4

C9

dioi

c

C8

dioi

c

C16

, tri

CH

3O, f

ame

C17

, iso

/ant

eiso

, fam

e

C29

C18

:1,

dioi

cac

id d

im.e

.

P18

C31

C33

C6

dioi

c

C16 C

18:1

Pyrogram of HA 0 year


11.0 16.0 21.0 26.0 31.0 36.0 41.0 46.0 51.0 56.0 61.011.0 16.0 21.0 26.0 31.0 36.0 41.0 46.0 51.0 56.0 61.0

Pyrogram of HA 0 year

G6

P2G1

P4

P6S1

S6

S14G14

/15

S4G4

P18

lignin derivatives

fatty acids

ω-hidroxy acids

alkane dioic acids

16C

16, 9

/10-

16 d

iCH

3O, f

ame

C9

10 d

iCH

3O, f

ame

C18

9,10

,18

triC

H3O

, fam

e

C16

, tri

CH

3O, f

ame

mid-chain hydroxy acids

alkanes

sterols

carbohydrates


basic lignin unitsgimnosperm woodgimnosperm wood

angiosperm woodangiosperm wood

2-methoxy-4- propenyl phenol

OH

OMe

Guaiacyl unit

2,6-dimethoxy-4- propenyl phenol

OH

OMeMeO

Siringyl units (prevalent)+guaiacyl

erbaceous planterbaceous plant P-hydroxy phenyl propene (prevalent) + guaiacyl and siringyl moieties

O HP-hydroxy

phenyl propene


from the data of lignin derivatives it is possible to determine

a structural index related to the degradation stage of lignis materials

the lignin derivatives with ketonic and acidic side chain indicate in fact an advanced

degradation process

OH

OMeMeO

OH O

OH

OMeMeO

OCH3

the

lignin derivatives with aldheidic side chain

indicate a

partial degradation

OH

OMeMeO

H O

OH

OMeMeO

OH

OH OH

whereas lignin products with intact whereas lignin products with intact side side chain chain are are representative representative of of unaltered unaltered or or

fresh plant tissuesfresh plant tissues

HA 0 year

Termochemolysis: lignin products (μg g-1dry weight)

Guaiacyl 5240 Ad/AlGΓG

c3.82.9

Ad/Al=G6/G4ΓG

=G6

/G14

+G15

OMe

OMeO

OMe

MeO

OMe

OMeOMe

OMe

C

MeO

OMe

OMeOMe

MeOC

OMe

HO

OMe

G4 G6G14 G15

2480p-hydroxy-phenyl propene

OMe

OMeO

OMe

Me

OMe

OMeOMe

OMe

OMeOMe

CO

MeO

OMe

OMeOMe

OMe

COMe

OMe

CO

OMe

OMe

CO

index

> 2 prevalence

of oxydisized structures

(high degradation)

Ad=acidic form G6Al=aldehydic form G4Undegraded structures

G14 +G15structural indexes


HA 0 year

2480

Termochemolysis: lignin products (μg g-1dry weight)

4950Siringyl


c3.82.9

Ad/AlSΓS

5.03.1

Ad/Al=S6/S4ΓS

=S6

/S14

+S15

p-idrossifenil-2-propene

OMe

OMeO

OMeMeO

OMe

OMeOMe

MeO

Me

OMe

OMeOMe

MeO

OMe

OMeOMe

OMe

C

MeO

MeO

MeO

OMe

OMeOMe

OMe

C

S14

MeO

MeO

OMe

OMeOMe

MeOC

S15

MeOS6OMe

OMeO

OMeMeO

OMe

HO

OMe

S4

MeO

Ad=acidic form S6Al=aldehydic form S4Undegraded structures

S14 +S15structural indexes

index

> 2 prevalence

of oxydisized structures

(high degradation)


HA 1 year

2370

59204.13.8

52104.93.9

HA 2 year

255058304.33.0

47305.13.6

HA 0 year

2480

4950Siringyl


c3.83.9

Ad/AlSΓS

5.04.1

p-idrossifenil-2-propene

MeO

OMe

OMeOMe

OMe

C

MeOHH

OC

OMe

OMe1,2,3-trimethoxy-1-

[3,4,5-

trimethoxyphenyl]propane

(threo/erythro)MeO

OMe

CH3

H OMe

cis/trans-1-methoxy-1-

(3,4-dimethoxyphenyl)-

1-propene

trans-3-

[3methoxyphenyl]

-3-propenoate

Termochemolysis

of soil umic

acids: lignin products (μg g-1

d.w.)

s.d. ±15%

HA 0 year

Termochemolysis

of soil humic

acids: μg g-1 dry weight

O OO O

O

O O

O

O

O

O

O O

O OO

D-Glucose, O-2,3,4,6-tetra-O-methyl-D-galactopyranosylO-2,4,6-tri-O-methyl- -D-galactopyranosyl-(2,3,5,6-tetra-O-methyl)

40 70 100 160 220 280 340 400 460 520 580 640 6700

50

100

45

7188

101

111

127 159

187

219

359 391 423

O

OO

O

O

O

O

O

O

O

O

-D-Glucopyranoside, 2,3,4,6-tetra-O-methyl-D-glucopyranosyl 2,3,4,6-tetra-O-methyl-40 60 100 140 180 220 260 300 340 380 420 460

0

50

100

45

88

101

111127 155

187

219 235 275 307

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

D-Glucose, O-2,3,4,6-tetra-O-methyl-á-D-glucopyranosyl 2,4,6-tri-O-methyl-D-glucopyranosyl2,3,4,5-tetra-O-methyl-

40 70 100 160 220 280 340 400 460 520 580 6400

50

100

75

88

101

127 155

187

219

carbohydratescarbohydrates 9650 (a) s.d. ± 40 % !


the large amount of hydroxyl groups in carbohydrates and polysaccharides produce an higher sensitivity of this compounds towards the analytical conditions of thermochemolysis

thermochemolysis is not well suited for the analysis of carbohydrates

the application of higher temperature for long time (30 min) and the alkaline condition provided by TMAH reagent, produce a large pyrolytic

rearrangement of the hydroxyl functional groups, with loss

of water molecules, cyclization

and aromatization of carbohydrates molecules

these drawbacks alter the response of polysaccharides to thermochemolysis•

decrease

the

released amount

of

carbohydrated products

(only qualitative or semiquantitative analysis)

•

lower reproducibility between replicates (higher standard errors)


HA 0 year

36100 C12

÷C30

(a)fatty acidsfatty acidscarbohydratescarbohydrates 9650 (a)

Termochemolysis

of soil humic

acids: alkyl components (μg g-1 d. w.)

overall

s.d. ± 15 %


50 70 90 110 130 150 170 190 210 230 250 270 3000

50

100

4355

69

74

87

97 129143

185 199 213267 298

0

50

100

55

69

74

83

87

97

111129

143

157171

185 199

213

269

283

295

326

M+

M+

O

OCH3

O

OCH3

Octadecanoic acid m.e.

Eicosanoic

acid m.e.


Fragmentation

of fatty acid methyl estersMcLafferty rearrangements

OH

CH3

O

+

OH

CH3

O

+

M/z 87

HO

CH3

O (CH2

)n

CH3

+ OHHCH3

O (CH2

)n

CH3

+

OH

CH3

OH (CH2

)n

CH3

+

OH

CH2CH3

O

+M/z 74

CH3

O

+ HO

(CH2

)n

CH3


HA 0 year

36100 C12

÷C30

(a)fatty acidsfatty acidscarbohydratescarbohydrates 9650 (a)

ω-hydroxyhydroxy acidsacids 12850 C14

÷C26

(a)

9150 C18:1

÷C24

(a)alkanealkane

dioicdioic acidsacids

midmid--chain chain hydroxyhydroxy

acidsacids 10350 C16, C18 (a)

αα−−ββ hydroxyacidshydroxyacids

2100 (a)C12

– C26

Termochemolysis

of soil humic


plant markersplant markerscutincutin

and and suberin suberin

componentscomponents

microbial markers

overall

s.d. ± 15 %



m+215m+159

m+

224

m+

265

m+

297 m+

339

50 70 90 110 150 190 230 270 310 350 3700

50

100 55

69

74

87

98

112154 224 265

297 339370M+

O

OOCH3

CH3

O

57 77 97 117 137 157 177 197 217 237 257 277 297 317 337m/z0

100

%

9571

55

5774 87

159

109

127

215

201183 330

M+

OCH3 O

OCH3CH3

O

Dioic acid

mid chain OH acid

O

OCH3

CH3

O

384

64 84 104 124 144 164 184 204 224 244 264 2840

100

%

55

74

8797

111143

304 324 344 364 384m/z

ω

position

M+

369

m+

352

-H+

m+

337

m+

321

m+

ω-hydroxy

acid


IREEA-Nanjing Agricultural University/ April 200840 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 4000

50

100

4357 71

83 97

111125

306325 353 398

O

O

O

40 50 70 90 110 130 150 170 190 210 230 250 2700

50

100

4155

69

75

83 97 111 143183 199 242 257

O

OO

117m+

3-(β) hydroxy acid

m+

339

2-(α) hydroxy acid

HA 0 year

36100 C12

÷C30

(a)fatty acidsfatty acids

6140C25

÷C33

(a)alkanesalkanes

3200 (a)

2230 (a)

sterolssterols

diterpenoidsditerpenoids

carbohydratescarbohydrates 9650 (a)

ω-hydroxyhydroxy acidsacids 12850 C14

÷C26

(a)

9150 C18:1

÷C24

(a)alkanealkane



acidsacids 10350 C16, C18 (a)


2100 (a)C12

– C26

Termochemolysis

of soil humic


plant markersplant markerscutincutin

and and suberin suberin

componentscomponents

microbial markers

plant markersplant markersangiosperm angiosperm gimnospermgimnosperm

overall

s.d. ± 15 %


HA 1 year

: 15100 C12

÷C30

(b)

9150 C14

÷C26

(b)

6300 C18:1

÷C24 (b)

: 3790 C25

÷C33

(b)

:

3210 (a)

:

2300 (a)

8700 (a)

8780 C16, C18

(b)

1900 (b)C12

– C26

HA 0 year

36100 C12

÷C30

(a)fatty acidsfatty acidsω-hydroxyhydroxy

acidsacids 12850 C14

÷C26

(a)

9150 C18:1

÷C24

(a)

6140C25

÷C33

(a)

3200 (a)

2230 (a)


acidsacids

alkanealkane



alkanesalkanes

sterolssterols

diterpenoidsditerpenoids

carbohydratescarbohydrates 9650 (a)

10350 C16, C18 (a)

2100 (a)C12

– C26

HA 2 year

: 14200 C12

÷C30

(b)

9300 C14

÷C26

(b)

5900 C18:1

÷C24 (b)

: 3900 C25

÷C33

(b)

:

3140 (a)

:

2250 (a)

8730 (a)

9200 C16, C18

(b)

2300 (b)C12

– C26

Termochemolysis

of soil humic

acids: μg g-1 dry weight


•

TMAH-thermochemolysis

technique is a rapid and effective method to obtain direct qualitative and quantitative evaluation of complex organic materials like humic

substances - thermochemolysis

released

more than hundred different molecules; plant biopolymers like lignin, waxes and aliphatic polyesters were recognized as the main sources of humic

acids

•

Lipids, lignin, and carbohydrates were the main components of soil HA extracted after organic matter addition - the main variations were

represented by a large decrease of bio-available lipids components such as fatty acids and linear hydrocarbon

•

Lower decrease and large persistence were found for biopolyester and lignin components – these findings confirm

previous results on the formation of Humic

substances through the selective accumulation of these recalcitrant organic molecules


Advantages and drawbacks of thermochemolysis

•

quick sample preparation and analysis1 sample (3 replicates) 1 day

•

simultaneous characterization of various organic components (lignin, lipids, biopolyesters, carbohydrates)

•

slow interpretation of complex chromatograms

•

thermochemolysis

products are ready for GC-MS analysis without any pre-treatment ( like purification andderivatization)

•

about 50% of TOC is not released: semi-quantitative evaluation

•

lower reproducibility: high standard deviation


Thanks for your attention

Documents

UNIVERSITY OF NAPOLI “FEDERICO II” Soil fertility … · 2018-07-30 · UNIVERSITY OF NAPOLI “FEDERICO II” AGRICULTURAL FACULTY. Soil Chemistry Department. Dr. Spaccini Soil