Pyrolysis-GC-MS in the structural research

of macromolecular natural organic matter

in Agricultural and Environmental Sciences

F. J. González-Vila*, G. Almendros**; J. A. González-Pérez*

*IRNAS-CSIC-Seville, Avda. Reina Mercedes, 10, 41012-Seville, Spain; fjgon@irnase.csic.es; jag@irnase.csic.es

** MNCN-CSIC-Madrid, Serrano 115bis, 41080-Madrid, Spain

humus@ccma.csic.es

PIRÓLISIS ANALÍTICA (PY-GC/MS)

Método degradativo que transforma compuestos complejos no volátiles en una mezcla de fragmentos volátiles por descomposición térmica en ausencia de oxígeno. Se realiza habitualmente a temperaturas de entre 400ºC y 800ºC y en condiciones de atmósfera inerte.

La separación e identificación de los productos de descomposición se realiza mediante cromatografía gaseosa (GC) y espectrometría de masas (MS), utilizando igualmente un gas inerte como transportador de los productos de la pirólisis.

Pyr

GC MS

PIRÓLISIS ANALÍTICA (PY-GC/MS)

En la pirólisis, se producen roturas de los enlaces por acción del calor.

Cuando la energía aplicada en las moléculas supera la energía de enlaces específicos se produce la disociación de éstos de forma predecible y reproducible.

Se puede obtener información en relación a la molécula original a través del análisis de los productos de degradación formados.

N Compounds released by Pyrolysis From Schulten et al. (1995). Biol. Fert. Soils 20: 174

Total ion Pyrogram of Pseudomelanoidin (Urea+Glucose) reference material

IDENTIFICATION OF NITROGEN

COMPOUNDS BY Py-GC/MS

N-containing Pyrrole

Pyridin

Indole

Benzene

Phenol

Naphthalene

Catechol

N

Lignin Guayacols-

Siringols

Vinylpheenol

OH

O O

Carbohydrate Humic acid

Lipids

Fatty acids

Alkanes

Alkenes

O

OH

Acetic acid

Alcohols (butanal)

Furanes

Cyclic ketones

Oxopropanoic acid

O

Aromatics

(methoxyl-lacking)

Py-GC/MS of natural organic mater (NOM)

Polysaccharides

Cellulose and hemicellulose

Lignins

(methoxyphenols)

G-type = Gymnosperms

S-type = Angiosperms

Unspecific aromatics

(non-methoxyphenols)

Lipids and alkyl

macromolecules

Nitrogen compounds

N N

OH

O

O

O

O O

O

O

OH

OH

O O

OH

O

Classification of pyrolysis

products in terms of soil

organic matter origin and

evolution

Pyrograms of BC reference materials: SIM traces for pyrogenic PAHs (m/z 178,

202, 228, 252, 276) and alkylic compounds (n-alkenes; m/z 85).

IDENTIFICATION OF BC CARBONOUS

COMPOUNDS BY Py-GC/MS

Py-GC/MS vs NMR

Soild State 13C NMR spectra

and Py-GC/MS pyrograms of a

BC sample isolated from a

marine sediment (Huelva,

Spain) and a BC containing

reference material (charred

chestnut wood).

A) Fundamental and practical research on Agricultural issues:

1.- Assessment of soil organic matter (SOM) molecular characteristics and the impact of

different soil use and management. (POSTER: OTR-P25)

2.- Monitoring composition and fate of crop residues and composted materials applied to

agricultural lands.

3.- Direct detection of agrochemicals i.e. pesticides or Si bearing coating/co-adjuvant agents.

B) Fundamental and practical research on Environmental issues:

4.- Monitoring the effects of wildfires on the SOM status

5.- Analysis of complex molecular lipids, black carbon (BC) and recalcitrant C-forms of interest

in Molecular Palaeobiogeochemistry

6.- Potential of pyrolysis techniques in directly detecting compounds i.e. pollutants or markers,

in solid samples (soils, sediments, bacterial mats plant/animal tissues) (POSTER: MAM-P37)

Py-GC/MS APPLICATIONS IN AGRICULTURA & ENVIRONMENT

COMPOSITION AND FATE OF CROP RESIDUES AND

COMPOSTED MATERIALS

Py-GC/MS

AGRICULTURE

42

44

46

48

50

52

54

56

58

60

62

2 4 5 6 7 8 11 12 13 14 15 16 18 19 20 21 22 23 25 26

Time (days)

Tem

pera

ture

(ºC

)PILE 0 PILE + BIO 1 PILE + BIO 2

1. Mesophyllic or moderate temperature stage.

2. Thermophyllic or high temperature stage.

Thermophyllic organisms able to digest more complex, insoluble molecules that have stronger chemical bonds such as proteins, fats and complex carbohydrates.

3. Cooling and maturation stage.

1 2 3

Non amended piles are unable to

sustain adequate thermophyllic

populations to appropriately catalyze

degradation processes.

Evolution of the temperature in piles of compost SS amended or not with

CBB with a tentative indication of different composting stages Azotobacter Azospirillum

COMPOSITION AND FATE OF CROP RESIDUES AND

COMPOSTED MATERIALS

Py-GC/MS

AGRICULTURE

REPRODUCIBILITY OF THE TECHNIQUE

COMPOSITION AND FATE OF CROP RESIDUES AND

COMPOSTED MATERIALS

Py-GC/MS

AGRICULTURE

COMPOSITION AND FATE OF CROP RESIDUES AND

COMPOSTED MATERIALS

Py-GC/MS

AGRICULTURE

BIOCOMPOSTING OF SINGLE WASTES (Characterization by direct Py at 500 ºC)

COMPOSITION AND FATE OF CROP RESIDUES AND

COMPOSTED MATERIALS

Py-GC/MS

AGRICULTURE

COMPOSITION AND FATE OF CROP RESIDUES AND

COMPOSTED MATERIALS

Py-GC/MS

AGRICULTURE

EFFECTS OF WILDFIRES ON THE SOM STATUS

Py-GC/MS

ENVIRONMENT

CA-Q1-05

CA-C1-05

CA-Q1-05

CA-C1-05

FIRE EFFECT ALONG SOIL PROFILE (Sierra de Cazorla, 2005)

Py-GC/MS

ENVIRONMENT

EFFECTS OF WILDFIRES ON THE SOM STATUS FIRE EFFECT ALONG SOIL PROFILE (Sierra de Cazorla, 2005)

EFFECTS OF WILDFIRES ON THE SOM STATUS

Py-GC/MS

ENVIRONMENT

FIRE EFFECT ALONG SOIL PROFILE (Controlled burning experiment 2011)

EFFECTS OF WILDFIRES ON THE SOM STATUS

Py-GC/MS

ENVIRONMENT

FIRE EFFECT ALONG SOIL PROFILE (Controlled burning experiment 2011)

Py-GC/MS

ENVIRONMENT

EFFECTS OF WILDFIRES ON THE SOM STATUS (Sierra de Aracena, 1999)

Aromatic area (160ppm-110ppm)

Aliphatic area (110ppm-45ppm)

Control

Burnt

Control

Burnt

24.0

59.7

62.9 23.0

Moltes gràcies a tots per la vostra atenció

Py-GC/MS

ENVIRONMENT