Pyrolysis Gas Chromatography Analysis Research Articles

Hyphenation of liquid chromatography and pyrolysis-flame ionization detection/mass spectrometry for polymer quantification and characterization

Size-exclusion chromatography (SEC) hyphenated to pyrolysis-gas chromatography (Py-GC) has been demonstrated as a powerful tool in polymer analysis. A main limitation to the wider application of the method are the long second-dimension Py-GC analysis times, resulting in limited first-dimension sampling and/or long overall run times. Therefore, we set out to develop an online hyphenated SEC×Py-MS/FID method, removing the GC separation and allowing for a drastically reduced second-dimension analysis time compared to SEC-Py-GC. The pyrolysis method had a cycle time of 1.31 min, which was facilitated by liquid nitrogen cooling of the programmable temperature vaporizer (PTV) used for pyrolysis. The developed method featured no molar mass discrimination for masses above ±1.3 kDa, rendering it applicable to most commercial polymer systems. The method was demonstrated on multiple samples, including a complex industrial sample, yielding chemical composition heterogeneity and in some cases sequence heterogeneity information over the molar mass distribution.

Kumagawa and Soxhlet Solvent Fractionation of Lignin: The Impact on the Chemical Structure.

We investigated the effects of solvent fractionation on the chemical structures of two commercial technical lignins. We compared the effect of Soxhlet and Kumagawa extraction. The aim of this work was to compare the impact of the methods and of the solvents on lignin characteristics. Our investigation confirmed the potentialities of fractionation techniques in refining lignin properties and narrowing the molecular weight distribution. Furthermore, our study revealed that the Kumagawa process enhances the capacity of oxygenated solvents (ethanol and tetrahydrofuran) to extract lignin that contains oxidized groups and is characterized by higher average molecular weights. Furthermore, the use of tetrahydrofuran after ethanol treatment enabled the isolation of lignin with a higher ratio between carbonyl and other oxidized groups. This result was confirmed by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), 13C NMR and two-dimensional (2D) NMR spectroscopies, gel permeation chromatography (GPC), and analytical pyrolysis-gas chromatography–mass spectrometry (Py-GC–MS) analysis. Ultraviolet–visible (UV–vis) spectra evidenced the enrichment in the most conjugated species observed in the extracted fractions. Elemental analyses pointed at the cleavage of C-heteroatom bonds enhanced by the Kumagawa extraction.

Engineering Lignin-Derived Carbon–Silicon Nanocomposite Electrodes: Insight into the Copyrolysis Mechanism and Process–Structure–Property–Performance Relationships

As a renewable source, available in a large quantity, it is rewarding to find applications for lignin with high added value. We report the use of lignin in synthesizing a three-dimensional, interconnected carbon/silicon nanoparticle (C/Si NP) composite material as a low-cost replacement to conventional anode materials synthesized using expensive and toxic solvents and binders such as polyvinylidene in today’s lithium-ion battery (LIB) manufacturing process. To understand how lignin pyrolysis chemistry and processing conditions affect the structure, mechanical property, and electrochemical performance of the synthesized electrode materials, the thermochemical conversion process was, for the first time, quantitatively investigated using analytical pyrolysis–gas chromatography–mass spectrometry (GC–MS) along with a suite of other analytical tools. Results suggest that the surface bonding interaction of the C/Si NPs was evolved from pristine Si to −Si–O–C–, to −O═Si═O–, with the increase of pyrolysis temperature. The −Si–O–C– bond plays a key role in enhancing the cohesive strength and thus improving the electrochemical performance of the Si composite electrode. The pyrolysis–GC–MS can serve as a useful tool to predict the optimal pyrolysis temperature or tailor the properties of the synthesized composite electrodes by controlling the pyrolysis conditions. This study elucidates the processing–structure–property–performance relationships among lignin pyrolysis chemistry, carbon material structure and properties, and the electrochemical performance of the resulting electrode materials. Such knowledge serves as a basis for designing lignin-derived composite materials for electrochemical energy storage applications.

ELEMENTAL COMPOSITION OF BIODIESEL PRODUCED BY FAST PYROLYSIS OF EUCALYPTUS LEAVES

In this study, temperature studies were studied on the production of a product from selected eucalyptus leaving samples. The bio-diesel yield from these samples was further determined using non-model methods and analytical pyrolysis-gas chromatography / mass spectrometry (Py-GC / MS). The fresh eucalyptus leaves were obtained from nearby forest of Godhra (Gujarat), India. Results of the Proximate analysis of eucalyptus leaves powder sample study shows that volatile matter, fixed carbon, ash content and moisture content are 61.70 %, 26.37%, 8.36 % and 3.57%, The results of the basic analysis indicate that the carbon, hydrogen, nitrogen, oxygen, and sulfur content is 89.17%, 7.36%, 1.01%, 1.98% and 0.26%, respectively. The higher heating value (HHV) of the biodiesel obtained from the biomass samples is 32.81 MJ/kg. Chemical composition analysis of Eucalyptus Biodiesel carried out and compared with standards. The study revealed that pyro-fuel is not only used as fuel but also can be purified and used as a commodity in the chemical and processing industries.

Disclosing the thermal reactions of aliphatic amines in the presence of TiO2 nanoparticles by multi-shot analytical pyrolysis

Analytical pyrolysis is a powerful tool to study the thermal behaviour of organic compounds, but relatively little information is available on the pyrolysis of amines, especially when bound to inorganic systems. In this study, we analysed aliphatic amines (propylamine, dipropylamine, tripropylamine, and tert-butylamine), both as pure compounds and bound to titania nanoparticles, using multi-shot analytical pyrolysis-gas chromatography coupled to mass spectrometry (Py-GC–MS) with a liquid nitrogen cryo-trap system. Desorption of amines was observed at 260 °C, while pyrolysis reactions were mostly observed at 600 °C. Pure amines underwent intermolecular reactions, generating heavier nitrogen-containing compounds. Conversely, amines bound to titania nanoparticles underwent loss of ammonia and hydrogen, and both inter- and intramolecular couplings generate unsaturated hydrocarbons and aromatics. Differences in the pyrolysis mechanisms were attributed to the catalytic effect of the nanoparticles. The present work provides fundamental information on the pyrolytic behaviour of aliphatic amines and on the catalytic effect of titania nanoparticles.

Depositional dynamics of the Devonian rocks and their influence on the distribution patterns of liptinite in the Sifa-1X well, Western Desert, Egypt: Implications for hydrocarbon generation

Samples from the Devonian succession in the Sifa-1X well located mid-way between the Egyptian Faghur Basin and the Libyan Cyrenaica Platform were examined in this study. The distribution of liptinite group macerals was investigated under reflected and transmitted light microscopy. Diverse and abundant liptinites of terrigenous and marine origin were identified. The palynological investigations included analysis of the miospores assemblages and palynofacies categories by multiple statistical approaches in addition to calculation of the sedimentation rates. These analyses signified four miospores biotopes and three palynofacies biotopes that were used to assess the ramps of paleoclimatological and paleoenvironmental changes during sedimentation. These biotopes were used to define a model of liptinite maceral distribution throughout the Devonian in the study area. The model suggested two different phases of basinal dynamics in terms of climate, sea level, and sedimentation rates, namely an Early-Middle Devonian transgressive phase and a Late Devonian regressive phase. Conditions during the Early-Middle Devonian transgressive phase were oxic to dysoxic with low sedimentation rates and oxic during the Late Devonian regressive phase. Oxygen depletion was under the threshold required to induce significant preservation of the quantity and quality of organic matter, including liptinite macerals. The redox conditions were confirmed by trace element analysis. The high oxygen level affected both the quantity and quality of the liptinite macerals and greatly reduced the preservation of the amorphous organic matter. The quality of the organic matter varied from kerogen type I, II, mixed types II/III and type III. The mixture of these kerogen types was assessed by organic elemental and pyrolysis gas chromatography analyses. In addition, the entire Devonian succession in the Sifa-1X well is in the oil window, as also indicated by miospore coloration. This indicates that the organic matter in the Devonian strata have the potential to generate oil and gas.

Chemical alteration patterns of ancient Egyptian papyri studied by Pyrolysis-GC/MS with in situ silylation

Analytical pyrolysis-gas chromatography coupled with mass spectrometry with in situ silylation using hexamethyldisilazane (Py(HMDS)-GC/MS) was employed to study a set of ancient Egyptian papyri. The aim was to investigate their chemical alteration patterns and to obtain information regarding the degradation pathways affecting them.In ancient Egypt, papyrus was widely exploited and its most important use was as a writing surface, created from strips of the pith found inside the stalk laid down in layers and dried under pressure. These strips were formed into rolls that were left intact or cut into sheets. From a chemical point of view, papyrus mainly consists of three biopolymers: cellulose, hemicellulose and lignin. Biological degradation due to fungi, bacteria or insects is the main cause of papyri decay in archaeological findings. However, thanks to the dry climate of the desert, the remains of many papyri have been found and recovered in Egypt.Py-GC/MS was used to identify roughly 90 compounds in the pyrograms of the various papyri. In terms of the main pyrolysis products derived from polysaccharides and lignin, compositional differences were detected between the archaeological papyri of several historical periods and sound modern papyrus sheets and plants. These chemical differences were derived from the modifications - such as depolymerisation, oxidation and depletion - undergone by both the polysaccharides and lignin.

Assessment of oil potentials for humic coals on the basis of flash Py-GC, Rock-Eval and confined pyrolysis experiments

Confined pyrolysis experiments (gold capsules), quantitative flash pyrolysis-gas chromatography (Py-GC) and Rock-Eval analysis were performed on ten coals from the Junggar Basin and seven coals from the Kuqa Depression, Tarim Basin, northwestern China. The maximum yields of liquid components in confined pyrolysis experimnets (MCPΣC8+), which reflect oil potentials, have close correlations with the yields of n-alkanes + n-alkenes (FPΣn-C7+) in flash Py-GC, but have poor correlations with Rock-Eval QI ((S1 + S2)/TOC) values. Thus, oil potentials of coals can be better predicted on the basis of FPΣn-C7+ yields from flash Py-GC analysis. Coals with FPΣn-C7+ yield >10.4 mg/g TOC can generate MCPΣC8+ yield >∼22.5 mg/g TOC or oil yield >∼40 mg/g TOC in confined pyrolysis or in natural systems and are effective oil source rocks. Although both Py-GC and Rock-Eval are open systems, the yields of total liquid components (FPΣC7+) obtained from flash Py-GC have poor correlations with, and are substantially lower than, Rock-Eval QI. In contrast, FPΣC7+ values have much better correlations with oil potentials (MCPΣC8+). Coals with higher oil potentials (MCPΣC8+) generate higher amounts of liquid components detected in flash Py-GC (FPΣC7+) than those with lower oil potentials but similar Rock-Eval QI. The correlations for parameters with gas to oil ratios (GOR) in confined pyrolysis are increasingly better in the sequence of Rock-Eval QI, H/C atomic ratios, MCPΣC8+, FPΣn-C7+ and FPΣn-C7+/ΣC7+ ratios. GOR of petroleum generated from coals within oil generative window can be reasonably predicted on the basis of FPΣn-C7+/ΣC7+ ratio from flash Py-GC analysis.

A critical evaluation of the degradation state of dry archaeological wood from Egypt by SEM, ATR-FTIR, wet chemical analysis and Py(HMDS)-GC-MS

An in-depth investigation was undertaken of the chemical changes to wood induced by degrading agents in dry burial environments. The degradation state of eleven wood samples from dry archaeological sites in Egypt was evaluated by combining the information obtained by scanning electron microscopy (SEM), wet chemical analysis (WCA), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and analytical pyrolysis gas chromatography mass spectrometry with in situ silylation (Py(HMDS)-GC-MS). The samples belonged to five different wood species (Faidherbia albida, Ficus sycomorus, Taxus baccata, Pinus sylvestris and Tamarix sp.) and came from three different archaeological sites corresponding to three different time periods (from ca. 1700 BC to ca. 1700 AD). The results were compared with sound reference wood of the same species.SEM enabled a fungal attack to be identified in some of the samples. WCA highlighted the preferential loss of lignin or carbohydrates in these samples, but also showed unusually high values of water-soluble substances in most of them. FTIR spectra acquired before and after the extraction of the samples revealed that this soluble fraction generally contained depolymerised carbohydrates and/or lignin units. Py(HMDS)-GC-MS was applied without any sample pre-treatment and was used to assess the alteration/depolymerisation of the individual wood components, thus complementing the picture regarding the chemical changes.The results showed that, unlike waterlogged archaeological wood, most of the degraded wood components – depolymerised carbohydrates and/or lignin – had not leached away from the dry wood matrix, and thus complicated the interpretation of data. The commonly used parameters, such as the H/L (holocellulose/lignin) ratio, failed to give a correct evaluation of the wood degradation when both carbohydrates and lignin were degraded. The preservation conditions of the samples were very variable, from very good to a high depletion of carbohydrates, to the preferential depletion of lignin, or comparable levels of carbohydrate and lignin degradation. This was sometimes observed within the same wood species and the same archaeological site.This highlighted how difficult the interpretation can be in order to correctly evaluate the multiple causes of degradation affecting dry archaeological wood. An analytical approach using complementary techniques appears to be essential.

Sewage sludge and waterworks sludge stabilization in sludge treatment reed bed systems.

In this study, results about sludge stabilization in sludge treatment reed bed (STRB) systems in two different systems, Hanningfield STRB 1 (England), treating waterworks sludge, and Stenlille STRB 2 (Denmark), treating surplus activated sludge, are presented. The study mainly focused on the effectiveness of the STRBs systems in stabilizing sludge organic matter; in fact, parameters correlated to biochemical and chemico-structural properties of organic sludge matter were determined. Dewatering and sludge stabilization were effective in both STRBs, as highlighted by total and volatile dry solids trend. β-glucosidase, phosphatase, arylsulphatase, leucine amino-peptidase and butyrate esterase activities, enzymes related to C, P, S, N and overall microbial activity, respectively, significantly declined along the profile in both STRBs. The determination of humic carbon highlighted the formation of a stable nucleus of humified organic matter in both STRBs in the deepest layers, thus meaning the successful stabilization of sludge organic matter for both kind of sludges. Similar conclusions can be drawn from pyrolysis gas chromatography analysis (Py-GC), which enables the characterization of soil organic matter quality from a chemical-structural point of view. The pyrolytic indices of mineralization and humification showed that in both STRBs the sludge organic matter is well stabilized.

Characterization and quantification of poly(acrylonitrile-co-1,3-butadiene-co-styrene)/polyamide 6 (ABS/PA6) blends using pyrolysis-gas chromatography (Py-GC) with different detector systems

Solid blend samples of poly(acrylonitrile-co-1,3-butadiene-co-styrene) (ABS) and polyamide 6 (PA 6) were characterized by analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and analytical pyrolysis-gas chromatography with flame ionization detector (Py-GC/FID) at 700°C, respectively. The separated compounds were identified using the mass spectral library as well as by calculation of the relative retentions. These blends have been chosen, since they play a dominant role in the automotive and other industries.A sixfold determination of the polymer blends was carried out respectively with both Py-GC/MS and Py-GC/FID methods. After characterization of the pyrolysis products, peak area ratios of five major degradation products were determined. Eventually, the obtained analytical results were then used to compare the precision of both Py-GC/MS and Py-GC/FID methods. Their relative standard deviations (RSD) of the determined peak area ratios were therefore compared. The performed statistical tests led to the conclusion that the Py-GC/FID method is more suitable for the quantification purposes than the Py-GC/MS method. Afterwards, the Py-GC/FID method has been validated successfully on the quantification of PA 6, using the peak area ratio of caprolactam to the main ABS degradation products. For the method validation the parameters linearity and working range, accuracy, limits of detection (LOD) and quantification (LOQ), and the recoveries, have been determined. A LOD of 6.02 (%, w/w) and a LOQ of 18.1 (%, w/w) were calculated. The recoveries for two blend-standards in the low and high content range were 100% and 97.7%, respectively. The calculated recovery of the investigated unknown sample was 93.3%.

Catalytic pyrolysis of lignin by using analytical pyrolysis-GC–MS

Catalytic pyrolysis of Kraft lignin and Scots pine wood over three different catalysts HZSM-5, Y-zeolite and Pd/C was studied. All experiments, with and without a catalyst, were carried out in small scale, using analytical pyrolysis gas chromatography mass spectrometry (Py-GC–MS) at 600°C. The catalytic pyrolysis result showed that the Kraft lignin was less altered over the tested catalysts in comparison to Scots pine wood (lignin). Over the acidic zeolite catalysts, aromatic hydrocarbons with one to three aromatic rings were formed from both samples, together with deoxygenated phenolic structures. Conversion of Scots pine wood–aromatic hydrocarbons was higher with both zeolites in comparison to Kraft lignin, especially when HZSM-5 was used. Y-zeolite changed the product distribution of Kraft lignin more than HZSM-5. With Y-zeolite, the proportion of benzenediols and p-hydroxypehnyl structures was increased, indicating demethylation and demethoxylation of lignin guaiacyl units. With Pd/C catalyst, deoxygenation of lignin guaiacyl units took place from both Scots pine wood and Kraft lignin. At high temperature pyrolysis with Pd/C, hydrogenation of double bonds was avoided. Conversion of Scots pine wood lignin–guaiacyl-type lignin derivatives with no oxygen-containing side chain structures was higher in comparison to Kraft lignin. Verification of the results with principal component analysis (PCA) revealed that catalytic pyrolysis treatments clearly differ from the non-catalytic treatment of Scots pine wood. In the case of Kraft lignin, only pyrolysis with Y-zeolite clearly changed the product distribution in comparison to non-catalytic pyrolysis. Based on the results, analytical Py-GC–MS proved to be a promising method for testing the behaviour of different catalysts.

Pyrolysis GC–MS as a novel analysis technique to determine the biochemical composition of microalgae

The biochemical composition of microalgae is a major factor in the feasibility of microalgae biofuel systems. Currently full compositional analysis entails tedious, costly and time consuming analysis methods. In the current research, an attempt has been made to use Analytical Pyrolysis Gas Chromatography Mass Spectrometry (Py–GC–MS) to determine the biochemical composition of microalgae. By identifying pyrolysis marker compounds of each main biochemical component of microalgae, the composition of algae samples could be estimated. This was aided by performing Py–GC–MS of a model protein, carbohydrate and lipid. Indole was shown to be a decomposition product from the protein fraction and its levels were consistent with the changing protein content. The lipid content of the microalgae could be estimated from the presence of alkanes and the carbohydrate fraction by the presence of 1,2-cyclopentanedione, 3-methyl-. A total of 26 different microalgae and cyanobacteria strains were investigated for their protein, carbohydrate and lipid levels using established analysis techniques. The biochemical compositions are compared to the results from the novel technique using Py–GC–MS and are shown to correspond well; R2 values were found to be 0.6–0.9. The results suggest that Py–GC–MS can be used as a rapid test for studying levels and changes in biochemical composition of different algae using one fast technique with minimal sample preparation.

Molecular characteristics of permanganate- and dichromate-oxidation-resistant soil organic matter from a black-C-rich colluvial soil

Samples from a colluvial soil rich in pyrogenic material (black C, BC) in north-west Spain were subjected to K2Cr2O7 and KMnO4 oxidation and the residual soil organic matter (SOM) was NaOH-extracted and analysed using analytical pyrolysis–gas chromatography–mass spectroscopy (Py-GC/MS) and solid-state 13C cross-polarisation magic angle spinning–nuclear magnetic resonance (13C CP MAS-NMR) in order to study the susceptibility of different SOM fractions (fresh, degraded/microbial, BC and aliphatic) towards these oxidising agents. Untreated samples that were NaOH-extracted were also analysed. The Py-GC/MS and 13C NMR indicated that KMnO4 promotes the oxidation of carbohydrate products, mostly from degraded/microbial SOM and lignocellulose, causing a relative enrichment of aliphatic and aromatic structures. Residual SOM after K2Cr2O7 oxidation contained BC, N-containing BC and aliphatic structures. This was corroborated by a relatively intense resonance of aromatic C and some signal of alkyl C in 13C NMR spectra. These results confirm that dichromate oxidation residues contain a non-pyrogenic fraction mainly consisting of aliphatic structures.

Carbon nanotube-reinforced crosslinked polyethylene pipes for geothermal applications: From synthesis to decomposition using analytical pyrolysis–GC/MS and thermogravimetric analysis

Abstract Carbon nanotube reinforced crosslinked high density polyethylene (PEX) nanocomposites were synthesized for geothermal applications requiring higher polymer thermal conductivity and a comprehensive thermal decomposition study was performed. The prepared nanocomposites were investigated by laser flash analysis and temperature modulated differential scanning calorimetry revealing a great enhancement on the specific heat capacity along with a further enhancement on the thermal diffusivity, resulting in some cases in an overall thermal conductivity increase of more than 200%. For the thermal decomposition or recycling process of the produced nanocomposites, a thorough examination of the decomposition process and its kinetics was performed by using thermogravimetry and analytical pyrolysis–gas chromatography–mass spectroscopy. From this systematic study, two possible decomposition mechanisms for PEX were proposed for the first time in literature and the decomposition kinetics results, which were conducted using isoconversional and model-fitting methods, were in agreement with the proposed mechanisms. From the complementary use of analytical pyrolysis and thermal analysis techniques study it was revealed that the presence of carbon nanotubes hinders the diffusion of the primary scission products of PEX and enhances its thermal stability.

Direct determination of cationic starches in paper samples using analytical pyrolysis

The current work presents a method for direct detection and quantification of cationic starch in paper samples. Based on analytical pyrolysis gas chromatography–mass spectrometry (Py-GC/MS), the method allows for simplified sample preparation. Furthermore, the proposed method assesses the amount of cationic starch in the presence of other starches. The cationic starch concentration in paper is calculated using a pyrolysis product from the cationic group. Therefore, the results of the described method are unbiased in the presence of other starch modifications. Validation characteristics of the method, such as standard error of calibration, limit of determination, linearity and accuracy, are reported. To demonstrate the accuracy of the novel method, a comparison against the existing reference quantification method, SCAN-P 91:09, from the Scandinavian Pulp, Paper and Board Testing Committee was performed.

Assessment of Soil Organic Matter Molecular Characteristics Related to Hydrophysical Properties in Semiarid Soils (Central Spain)

The objective of this study is to analyze soil hydrophysical properties in addition to the molecular composition of the organic matter in semiarid Mediterranean cereal agroecosystems. Aggregate water-stability, total porosity, water holding capacity, and b and c parameters of the Kostiakov's equation for soil infiltration were determined using a double-ring infiltrometer. The soil humic acid (HA) was isolated and characterized mainly by analytical pyrolysis-gas chromatography mass spectrometry. Multivariate data treatments suggested favourable hydrophysical parameters associated to HAs with a substantial aliphatic domain. Soils with HAs consisting of condensed aromatic structures, often considered to correspond to advanced stages of humification and high resilience, do not coincide with those displaying favourable hydrophysical properties. The results discussed in this article provide support for moderate aliphatic hydrophobicity to be considered as a soil organic matter quality parameter positively influencing hydrophysical properties of semiarid soils.

Application of pyrolysis–gas chromatography/mass spectrometry for the identification of polymeric materials in failure analysis in the automotive industry

The application of analytical pyrolysis–gas chromatography mass spectrometry (Py–GC/MS) in the failure analysis of two hydraulic cylinders and their rubber membranes from the automotive industry were presented.

Interferences in the direct quantification of bisphenol S in paper by means of thermochemolysis

This article analyses the interferences in the quantification of traces of bisphenol S in paper by applying the direct analytical method “analytical pyrolysis gas chromatography mass spectrometry” (Py-GC/MS) in conjunction with on-line derivatisation with tetramethylammonium hydroxide (TMAH). As the analytes are simultaneously analysed with the matrix, the interferences derive from the matrix. The investigated interferences are found in the analysis of paper samples, which include bisphenol S derivative compounds. As the free bisphenol S is the hydrolysis product of the bisphenol S derivative compounds, the detected amount of bisphenol S in the sample may be overestimated. It is found that the formation of free bisphenol S from the bisphenol S derivative compounds is enhanced in the presence of tetramethylammonium hydroxide (TMAH) under pyrolytic conditions. In order to avoid the formation of bisphenol S trimethylsulphonium hydroxide (TMSH) is introduced. Different parameters are optimised in the development of the quantification method with TMSH. The quantification method based on TMSH thermochemolysis has been validated in terms of reproducibility and accuracy.

Identification and classification of glucose-based polysaccharides by applying Py-GC/MS and SIMCA

This paper describes a simplified method for the identification of glucose-based polymers (polysaccharides). The method developed consists of classifying the results from analytical pyrolysis gas chromatography mass spectrometry (Py-GC/MS) by applying soft independent modelling of class analogy (SIMCA). Since the amount of inorganic compounds in the sample influences the pyrolysis results, the classification model is applied to the pyrolysis results obtained from samples in their original form and after pre-treatment. The pre-treatment aims at removing the inorganic compounds from the polysaccharides and consists of washing out the samples with acid solutions. Depending on the acid used, pyrolysis results may differ. Therefore, the pre-treatment impact on the pyrolysis results is evaluated as well. After optimisation of the sample pre-treatment, it is possible to discriminate between various subgroups of starches (native, cationic, oxidised starches and dextrin). This indicates that appropriate sample pre-treatment in combination with chemometric data evaluation results in a clear classification of very similar samples showing very similar pyrograms. The methodology developed facilitates the analysis and identification of deposits originating from polysaccharides found in paper production processes.