Automated Mass Spectral Deconvolution And Identification System Research Articles

Untargeted GC-MS metabolomics to identify and classify bioactive compounds in Combretum platypetalum subsp. oatesii (Rolfe) Exell (Combretaceae).

Combretum platypetalum is used in traditional African healing practices against different infections. Unfortunately, no scientific knowledge of its phytochemical composition exists, except for the isolation of two compounds from the leaves. Scientific study has been limited to the leaves only, despite the applications of stems and roots in traditional medicine practice and natural product drug discovery programs. Omics was applied to identify and classify different volatile and semivolatile bioactive compounds in the leaf, stem, and root parts of C. platypetalum. The thermal stability of the plant constituents at 60-65°C extraction temperature by Soxhlet and maceration at room temperature on the type, class, and concentration of compounds in the leaf was further investigated. A GC-MS untargeted metabolomics approach, automated deconvolution by the Automated Mass Spectral Deconvolution and Identification System (AMDIS) for GC-MS data, preprocessing by Metab R, and multivariate statistical data analysis were employed in this study. A total of 97 phytoconstituents, including 17 bioactive compounds belonging to the terpenoids, flavonoids, long-chain fatty acids, and other unclassified structural arrangements distributed across C. platypetalum, were identified for the first time. A correlation (r = 0.782; P = 0.000) between Soxhlet and maceration extraction methods relative to resolved chromatographic peak areas of metabolites was established. Findings corroborate the reported bio-investigation of its leaf extracts, its traditional uses, and previous findings from the Combretum genus. The results substantiate the possible applications of C. platypetalum in natural product drug discovery and provide a guide for future investigations.

Polar and non-polar fraction from Origanum vulgare spp. hirtum methanolic extract – differences in their bioactivity on Chlamydomonas reinhardtii test system

Aim: To compare the bioactivity of both polar and non-polar fraction of Origanum vulgare spp. hirtum methanolic extract on Chlamydomonas reinhardtii. Material and methods: The polar and non-polar fractions were derived from aerial parts of Origanum vulgare ssp. hirtum, collected during the flowering stage from the ex-situ collection of IBER-BAS. GC/MS analysis of both fractions was done following the standard protocol. The measured mass spectra were deconvoluted by the Automated Mass Spectral Deconvolution and Identification System (AMDIS), before comparison with the databases. Chlamydomonas reinhardtii 137C+ (WT) was used as a test system. Spot-test, cell survival fraction (SF), test of “visible mutations” and CFGE (for measurement of induced DNA double-strand breaks (DSBs)) were applied. Results: The polar fraction did not possess genotoxic, mutagenic as well as DNA-damaging effect. The situation with the non-polar fraction was quite different. Even at the lowest concentration of 250 ppm, cell survival was decreased by 60% (SF = 0.41 ± 0.08). Treatment with concentrations equal to/or greater than 500 ppm resulted in around 100% lethality. A mild mutagenic effect was obtained for the concentration of 250 ppm non-polar fraction (IM = 4.83 ± 0.004). Well-expressed and concentration-dependent induction of DSBs for even the strong DNA fragmentation was observed after the treatment with the non-polar fraction. Conclusions: The different bioactivity of the two fractions correlated well with their different chemical composition. The polar fraction, rich in sugars, organic acids and flavonoid glycosides, did not possess genotoxic and mutagenic potential. The strong genotoxic potential of the non-polar fraction might be related to carvacrol content (37.08%), which is not present in the composition of the polar fraction. To the best of our knowledge, this study provides the first information that the carvacrol-rich non-polar fraction of Origanum vulgare spp. hirtum methanolic extract possesses genotoxic, mutagenic and DNA damaging effect on some low eukaryotes, such as C. reinhardtii. Further experiments with carvacrol should be done in order to clarify the exact mechanism of action.

Open Characterization of Vaping Liquids in Canada: Chemical Profiles and Trends.

Currently, there is a lack of comprehensive data on the diversity of chemicals present in vaping liquids. To address this gap, a non-targeted analysis of 825 vaping liquids collected between 2017 and 2019 from Canadian retailers was conducted. Prior to mass spectrometry analysis, samples were diluted 1:500 v/v with methanol or acetonitrile. Chemical compound separation and analysis was carried out using gas chromatography and triple quadrupole mass spectrometry (GC-MS/MS) systems operated in the full scan mode and mass range of 35–450 m/z. Mass spectrum for each sample was obtained in electron ionization at 70 eV and processed. Non-targeted identification workflow included use of automated mass spectral deconvolution and identification system (AMDIS), where required, as well as a number of commercially available spectral libraries. In order to validate identities, an in-house database of expected compounds previously detected in vaping liquids was used along with genuine analytical standards for compounds of interest. This resulted in a dataset of over 1,500 unique detected chemicals. Approximately half of these chemical compounds were detected only once in a single product and not in multiple products analyzed. For any sample analyzed, on average, 40% of the chemical constituents appeared to have flavouring properties. The remainder were nicotine and related alkaloids, processing, degradation or indirect additives, natural extractives and compounds with unknown roles. Data published here from the project on the Open Characterization of vaping liquids is unique as it offers a detailed understanding of products’ flavour chemical profiles, the presence and frequency of chemicals of potential health concern, as well as trends and changes in products’ chemical complexity over a three-year period. Non-targeted chemical surveillance such as this present valuable tools to public health officials and researchers in responding to emergent issues such as vaping associated lung injury or informing chemical based strategies which may be aimed at addressing product safety or appeal.

AMDIS-Metab R data manipulation for the geographical and floral differentiation of selected honeys from Zambia and Botswana based on volatile chemical compositions using SPME–GC–MS

A metabolomic classification of commercial and unprocessed organic honeys from Zambia and Botswana based on geographic and floral origins was done forthwith. Classification using gas chromatography–mass spectrometry/solid phase microextraction (GC–MS/SPME) was accomplished on three commercial and three unprocessed organic honeys. The Automated Mass spectral Deconvolution and Identification System (AMDIS), Metab R, an R platform application and MINITAB version 14 partial least squares (PLS) were used for data processing. Sixteen volatile metabolites in three commercial and 40 in three unprocessed organic honeys were identified, confirmed and formed the basis for differentiation. Database search showed that the honeys were polyfloral with major ingredients coming from common flowering plants, conifers and other gymnosperms such as Carica papaya L. (papaya), Monstera deliciosa (ceriman) and fruits, i.e., guava, melon and pineapple, endemic in the areas from which the honeys originated from.

AMDIS & EXCEL: A Powerful Combination for Evaluating THM-Py-GC/MS Results from European Lacquers

ABSTRACTPyrolysis gas chromatography/mass spectrometry using tetramethylammonium hydroxide (TMAH) for thermally-assisted hydrolysis and methylation (THM-Py-GC/MS) is a powerful analytical technique for comprehensive characterization of organic materials in European lacquers. A daunting challenge, though, is systematically sorting through the vast number of chromatographic peaks in order to accurately locate marker compounds that are characteristic of lacquer artists’ materials. AMDIS (Automated Mass spectral Deconvolution and Identification System) software, developed by NIST, is proven to be capable of extracting and locating library marker compounds in highly complex GC/MS data files. An AMDIS marker compound library of more than 1400 compounds representing Asian and European lacquer and a number of other artists’ materials has been compiled from information in various publications and private communications. A customized Excel workbook was developed to semi-automatically analyse and interpret the marker compound information in the AMDIS search report, using interpretation guides based upon knowledge shared by experts in material characterization that aid in accurate identification. These software tools have been used in training workshops, organized by the Getty Conservation Institute, by scientists with varying levels of GC/MS experience to successfully identify artists’ materials in complex samples from lacquered works of art. Based upon positive feedback from the workshop participants and successful application in their laboratories, we have concluded that the tools may be considered as an Expert System for Characterization with AMDIS Plus Excel (ESCAPE). Examples will be shown for using ESCAPE to identify a wide range of natural products in samples from lacquered objects and easel paintings.

Benefit of the Use of GCxGC/MS Profiles for 1D GC/MS Data Treatment Illustrated by the Analysis of Pyrolysis Products from East Asian Handmade Papers.

In this study, we report the use of pyrolysis-GCxGC/MS profiles for an optimized treatment of data issued from pyrolysis-GC/MS combined with the automatic deconvolution software Automated Mass Spectral Deconvolution and Identification System (AMDIS). The method was illustrated by the characterization of marker compounds of East Asian handmade papers through the examination of pyrolysis-GCxGC/MS data to get information which was used for manually identifying low concentrated and co-eluting compounds in 1D GC/MS data. The results showed that the merits of a higher separation power for co-eluting compounds and a better sensitivity for low concentration compounds offered by a GCxGC system can be used effectively for AMDIS 1D GC/MS data treatment: (i) the compound distribution in pyrolysis-GCxGC/MS profiles can be used as "peak finder" for manual check of low concentration and co-eluting compound identification in 1D GC/MS data, and (ii) pyrolysis-GCxGC/MS profiles can provide better quality mass spectra with observed higher match factors in the AMDIS automatic match process. The combination of 2D profile with AMDIS was shown to contribute efficiently to a better characterization of compound profiles in the chromatograms obtained by 1D analysis in focusing on the mass spectral identification. Graphical abstract.

Extending our tools and resources in the non-conventional industrial yeast Xanthophyllomyces dendrorhous through the application of metabolite profiling methodologies

IntroductionXanthophyllomyces dendrorhous is a non-conventional industrial yeast. It has the unique ability among yeasts to produce geranylgeranyl pyrophosphate derived terpenoids such as carotenoids and in particular the high value pigment astaxanthin.ObjectiveIn order to fully exploit the industrial potential of Xanthophyllomyces using modern industrial biotechnology approaches the further development of “omic” resources in this organism are required to build on the now sequenced and annotated genome. To contribute to this goal, the present study has developed and implemented an efficient metabolite profiling system comprised of, quenching, extraction and associated GC–MS and UPLC analysis.MethodFour quenching methods and five extraction methods compatible with GC–MS and UPLC profiling were tested and validated by analysing steady state metabolite changes of Xanthophyllomyces cultivated at laboratory scale in liquid shake culture at lag, exponential and early and late stationary phases.ResultsA customised Automated Mass Spectral Deconvolution and Identification System (AMDIS) library has been created for Xanthophyllomyces, over 400 compounds are present in the library of which 78 are detected and quantified routinely in polar and non-polar derived extracts. A preliminary biochemical network has been constructed. Over a standardised laboratory growth cycle, changes in metabolite levels have been determined to create reference point for future strain improvement approaches and the initial biochemical network construction. Correlation analysis has illustrated that astaxanthin formation correlates positively with different sectors of intermediary metabolism (e.g. the TCA cycle intermediates and amino acid formation), “short” saturated fatty acids and β-carotene, while other metabolites are reduced in response to astaxanthin production. These sectors of intermediary metabolism offer potential future targets for the manipulation resulting in the generation of strains with improved titres of given terpenoids.DiscussionIn summary a robust metabolite profiling system for Xanthophyllomyces is in place to further our understanding and potential exploitation of this underutilised industrial yeast.

Influence of sublethal doses of acetamiprid and halosulfuron-methyl on metabolites of zebra fish (Brachydanio rerio)

Acetamiprid, a neonicotinoid pesticide, is reported to have adverse sublethal effects on non-target beneficial organisms. Halosulfuron-methyl (HM), one of the most widely used herbicides in agriculture, has high ecotoxicity to aquatic plants and animals. In this study, a GC–MS-based metabolomics approach was used to investigate the toxicity of acetamiprid and HM. The Automated Mass Spectral Deconvolution and Identification System (AMDIS) software program and the retention index method were used to identify 51 metabolites in zebra fish (Brachydanio rerio). Changes in metabolites showed that acetamiprid and HM disturbed amino acid (e.g., leucine, valine, serine, glycine, proline, and alanine) metabolism, the TCA cycle (malic acid and fumaric acid), and the balance of neurotransmitters (glutamic acid, taurine, and glycine). The change in metabolites in the liver, head, and blood indicated that metabolites in the liver were more sensitive than those in the head and blood. Overall, on the basis of the change in metabolites, we identified a potential risk to zebra fish exposed to sublethal doses of acetamiprid and/or HM.

Beyond the basics: A systematic approach for comprehensive analysis of organic materials in Asian lacquers

Identification of organic materials in Asian lacquers presents many challenges due to their complex formulations and the limited solubility of the main component, which is catechol-rich sap from three species of Anacardiaceae trees that crosslinks to form a hard film. Pyrolysis-gas chromatography–mass spectrometry with thermally assisted hydrolysis and methylation using tetramethylammonium hydroxide (THM-Py-GC–MS) has been shown to produce a wide range of marker compounds useful for identifying the catechol components and lacquer additives such as drying oils, natural resins, proteins, starch, and colorants. However, interpreting the test results is quite challenging because of the sheer number of compounds produced by pyrolysis and the wide range of materials that have been used in traditional Asian lacquer formulations. An expert system developed by scientists at the Getty Conservation Institute and conservators at the J. Paul Getty Museum for a workshop entitled ‘Recent Advances In Characterizing Asian Lacquers’ (RAdICAL) utilizes software tools to overcome challenges in data analysis and marker compound interpretation, making it possible for even relative newcomers to Py-GC–MS to identify materials in lacquered objects systematically. Automated Mass spectral Deconvolution and Identification System (AMDIS), a freeware program developed by the National Institute of Standards and Technology (NIST), systematizes GC–MS data analysis by rapidly deconvoluting chromatograms, identifying individual peaks, and then searching the results against a user library of marker compounds, producing a simple report that lists the names, retention indices, and peak areas for all the compounds identified in the sample. The authors have produced a custom RAdICAL compound library, compiled from in-house studies of reference samples made from mixtures of raw or processed lacquer mixed with additives, and supplemented by published work from other researchers. The lists include numerous oxidation products of the alkyl- and alkenyl-substituted catechols, and alkyl- and alkenyl-substituted benzenes in the tree saps identified in studies of aged lacquer replicas, many of which have diagnostic purposes. A specialized Excel workbook developed for RAdICAL can import the AMDIS report, organize the marker compound results by class of artists’ materials, and perform automatic calculations to display sorted information for each material in specialized diagnostic graphs. Expert knowledge relating raw materials to their associated marker compounds, obtained from in-house research, publications and personal communications has been embedded into the individual Excel worksheets. This aids users of the workbook in verifying the presence or absence of materials in their lacquer samples, based on the marker compound distributions. All of the final results are presented in a pre-formatted comprehensive analytical report. Extensive lists of analytical data for marker compounds from the major classes of organic additives used in Asian lacquer formulations provide researchers the information needed to identify these markers in unknown lacquer samples. As other researchers contribute marker compound information for further lacquer materials and the knowledge for interpreting them, the capabilities of the RAdICAL expert system will continue to expand.

Compound identification in metabolomics: a study with the use of two different GC data processing systems

The present paper reports a comparison study of two data processing procedures in GC–MS metabolome components investigation based on two modern softwares: Automated Mass Spectral Deconvolution and Identification System (AMDIS) and GC–MS Solution Postrun Analysis (GC–MS SPA). GC–MS SPA is intended for manual integration and identification, while AMDIS is proposed as a fast, and automatic data analysis tool. Both methods are based on the same free-access library. In the present study, 12 compounds previously detected in a metabolomic fingerprint of grasshopper abdominal secretion, were tested at three concentration levels: 2.5, 5 and 10 μg/mL. The processing procedures were evaluated by comparison of peak area ratio for each tested concentration. The obtained results proved that processing with the use of AMDIS was more sensitive and enabled the identification of all compounds at the lowest selected concentration. Additionally, the differentiation of structurally similar compounds was possible with the use of AMDIS software.

Study on composition of essential oils in three different origins' Curcumae Rhizoma by AMDIS and retention index

To compare the differences of essential oils extracted from Curcumae Rhizoma with different origins. The TIC of the essential oils of Curcumae Rhizoma from three different origins recorded by CP(2010) , were investigated by GC-MS combined with automated mass spectral deconvolution and identification system(AMDIS),steps as follow： firstly, overlapped peaks were resolved by AMDIS,secondly, NIST11.L standard MS spectral database combined with retention index were used to assist qualitative analysis, thirdly, the peak area of each split peak were determined by choosing the characteristic fragment ion peak, finally, the relative percentage contents of each compounds were determined through peak area normalization method. The results showed that the components of the essential oils of Curcumae Rhizoma from three origins were different from each other at various degree. In conclusion, the types and content of essential oils could be an indicator to evaluate the quality of Curcumae Rhizoma from different origins and its geoherbalism.

Tuber metabolic profiling of resistant and susceptible potato varieties challenged with Phytophthora infestans

Selection of disease resistant potato varieties for conventional breeders is a time consuming and labor intensive process and most of the times lead to the results that are spatiotemporally inconsistent. Metabolic phenotyping was employed to develop metabolic criteria that can be used to distinguish potato genotypes with disease resistance. Tubers of potato varieties (Caesar and AC Novachip) moderately resistant and susceptible to Phytophthora infestans were inoculated with pathogen or water, and metabolites were analyzed using Gas Chromatography-mass Spectrometry (GS/MS). Disease severity was measured as the volume of diseased tissue calculated based on lesions volume at 2-day intervals after inoculation. Disease severity was 4.17 and 0.61 cm3 for varieties Caesar and AC Novachip respectively. Seventy seven metabolites were tentatively identified using Automated Mass spectral Deconvolution and Identification System (AMDIS) and univariate ANOVA showed that 37 metabolites had significant treatment effects with nine identified as resistance related and five as constitutive metabolites. Four metabolites, constitutive or induced showed significant increase in their abundance in pathogen inoculated tubers. A total of 21 metabolites were considered as pathogenesis related which showed changes in abundance after pathogen challenge. A canonical discriminant analysis of the 37 metabolites identified metabolic phenotypes correlating to disease severity phenotypes. The metabolites were mainly from sugars, fatty acids, and phenolic compounds which of some may have potential antimicrobial activity. Among resistance related metabolites, the abundances of 1H-Indole-3-acetonitrile, trihydroxybutyrate, D-Mannitol, dihydocoumarin, and propanoate were significantly higher in Caesar. The potential application of metabolic profiling technology for high throughput screening of potato breeding lines against potato late blight is discussed.

Analysis of Whiskey by Dispersive Liquid–Liquid Microextraction Coupled with Gas Chromatography/Mass Spectrometry: An Upper Division Analytical Chemistry Experiment Guided by Green Chemistry

Analysis of whiskey samples prepared by a green microextraction technique, dispersive liquid–liquid microextraction (DLLME), before analysis by a qualitative gas chromatography–mass spectrometry (GC/MS) method, is described as a laboratory experiment for an upper division instrumental methods of analysis laboratory course. Here, aroma compounds in whiskey samples (n = 11) were extracted using ultrasound-assisted DLLME with chloroform (as extraction solvent). The chloroform extract was analyzed by GC/MS with data manipulation by AMDIS (automated mass spectral deconvolution and identification system) to allow for comparisons between whiskey samples. Aroma compounds commonly reported in the literature (furfural, isoamyl acetate, 5-methyl furfural, ethyl esters, phenylethyl alcohol, whiskeylactone, and vanillin) were tentatively identified based upon the match to the MS library. This unique laboratory allows students to engage in a real-world analysis of a high-value product and to explore the use of AMDIS to...

Systematic forensic toxicological analysis by GC‐MS in serum using automated mass spectral deconvolution and identification system

Non-targeted screening of body fluids for psychoactive agents is an essential task for forensic toxicology. The challenge is the identification of xenobiotics of interest from background noise and endogenous matrix components. The aim of the present work was to evaluate the use of an Automated Mass Spectral Deconvolution and Identification System (AMDIS) for gas chromatography-mass spectrometry (GC-MS) based toxicological serum screening. One hundred fifty serum samples submitted to the authors´ laboratory for systematic forensic toxicological analysis underwent GC-MS screening after neutral and basic liquid-liquid extraction. Recorded datasets were routinely evaluated both by experienced personnel and automatically using the AMDIS software combined with the Maurer/Pfleger/Weber GC-MS library MPW_2011. The results from manual and automated data evaluation were then systematically compared. AMDIS parameters for data deconvolution and substance identification had been successfully adapted to the GC-MS screening procedure in serum. The number of false positive hits could substantially be reduced without increasing the risk of overlooking relevant compounds. With AMDIS-based data evaluation, additional drugs were identified in 25 samples (17%) that had not been detected by manual data evaluation. Importantly, among these drugs, there were frequently prescribed and toxicologically relevant antidepressants and antipsychotic drugs such as citalopram, mirtazapine, quetiapine, or venlafaxine. For most of the identified drugs, their serum concentrations were in the therapeutic or subtherapeutic range. Thus, our study indicated that automated data evaluation by AMDIS provided reliable screening results. Copyright © 2015 John Wiley & Sons, Ltd.

PTH-123 Urinary volatile organic compounds as a biomarker for hepatocellular carcinoma (HCC)

<h3>Introduction</h3> Primary liver cancer is the third largest contributor to cancer mortality in the world, with more than half a million people worldwide diagnosed each year. Over the last 3 decades the incidence and mortality of HCC has been steadily increasing. The major factors contributing to survival are the degree of the underlying liver disease and the size of the tumour at diagnosis. Therefore early diagnosis is vital to improve outcomes. Volatile organic compounds (VOCs) have been investigated as biomarkers of a range of disorders. We report the first pilot study of urinary VOCs as biomarkers for HCC. <h3>Method</h3> A 400 ul urine sample was collected from 60 patients with a confirmed diagnosis of cirrhosis: 33 patients without and 27 patients with HCC. Urine samples were subsequently freeze-dried and analysed by Gas Chromatography – Mass Spectrometry. VOCs were identified and quantified using an in-house pipeline involving the Automated Mass Spectral Deconvolution and Identification System (AMDIS), the NIST mass spectral library and the R package Metab. Statistical analyses were performed using the R software and the web-tool Metaboanalyst. <h3>Results</h3> A total of 118 VOCs were identified across all samples. There were significantly higher number of VOCs identified in the cirrhotics without HCC compared to those with HCC (<i>t</i>-test, <i>p-value = 0.034</i>). Categorical comparison for prevalence demonstrated methanethiol to be less prevalent VOC in those with HCC (<i>t</i>-test, <i>p-value = 0.0083</i>). Comparison of VOCs abundances reported methanethiol at significantly higher levels in patients without HCC (<i>t</i>-test, <i>p-value = 0.0088</i>) (Figure 1). PLS-DA of those with HCC showed great separation between those with alcohol and viral hepatitis as the underlying aetiology. A supporting vector machine (SVM) model was then developed using methanethiol and additional selected features of qualitative data. After validation using a repeated 10 fold cross validation scheme, the SVM model returned a mean accuracy of 80% for the diagnosis of HCC. <h3>Conclusion</h3> The results presented here are in agreement with the literature. In particular, the decrease of methanethiol appears to have the most promise as a biomarker for the development of HCC. The model developed here showed great accuracy in classifying urine samples from patients with HCC, which indicates a great potential of VOCs as diagnosis or screening tool. A larger study would be required to investigate it further. <h3>Disclosure of interest</h3> None Declared.

GC/MS technique and AMDIS software application in identification of hydrophobic compounds of grasshoppers’ abdominal secretion (Chorthippus spp.)

The automated mass spectral deconvolution and identification system (AMDIS) is a modern analytical tool, mostly used as a data processing method in environmental studies. The most attractive feature of that software is a fast, automatic data processing, which includes removal of interferences from the overlapping peaks and purification of the obtained mass spectra. The identification of analytes is based on their retention time and retention index and on comparison of the spectra obtained in GC/MS analysis with the spectra from the library of the National Institute of Standards and Technology (NIST).The main aim of the study reported was to elaborate and test a new data processing method with the use of AMDIS software for identification of lipidomic compounds present in the grasshopper's abdominal secretion. For the first time to the best of our knowledge, we have demonstrated the usage of AMDIS in a lipidomic study concerning a complex insect matrix. The samples processed with AMDIS software were analyzed with the use of GC/MS in order to determine the main fatty components of grasshoppers’ abdominal secretion. The purification, concentration and fractionation of compounds present in a complex insect matrix were investigated with the use of liquid–liquid extraction as a pretreatment procedure. Moreover, a double-step derivatization process was carried out in order to obtain more volatile and stable derivatives of polar, non-volatile components of insects’ secretion. This process, necessary for GC/MS analysis, was performed with the use of methoxyamine hydrochloride dissolved in pyridine and a mixture of bis-N-O-trimethylsilyl trifluoroacetamide (BSTFA) and chlorotrimethylsilane (TMCS).As a result, we obtained a fast, automatic method based on the use of AMDIS software, which enabled identification of 28 analytes, mainly fatty compounds. Moreover, 10 compounds out of 28 were determined to appear with 100% frequency in the tested samples, namely: seven fatty acids, one sterol, one organic acid and one alkaloid.The last part of our study was statistical analysis of average intensities of signals of compounds identified in grasshopper's abdominal secretion in order to differentiate insects collected at two distant locations in Poland: Starogard Gdański and Łubianka meadows.

Study on composition of essential oil in above-ground and root of Bupleurum malconense and root of B. chinense by AMDIS and retention index

Chemical constituents of the essential oil in above-ground and root of Bupleurum malconense and root of B. chinense were investigated by GC-MS compiled with automated mass spectral deconvolution and identification system (AMDIS) and retention index. The results showd that the components of essential oil in B. malconense have some similarities with the one in B. chinense, and both of them have the higher content of caryophyllene oxide which is an active component of anti-inflammatory and analgesic. These results suggested that as a local substitute, B. malconense has a certain scientific basis of the treatment for cold fever.

Combination of programmable temperature vaporizer-large volume injection gas chromatography-mass spectrometry and automated mass spectral deconvolution and identification system for the determination of 32 pesticides in fruits and vegetables

An analytical method was developed for the simultaneous determination of 32 pesticides including organophosphorus, organochlorine, pyrethroid and carbamate pesticides in fruits and vegetables using gas chromatography-mass spectrometry (GC-MS). The sample was extracted with acetonitrile, and the organic layer was cleaned up with ENVI-Carb and LC-NH2 cartridges. A large volume of 20 µL purified solution was injected into the GC system using programmable temperature vaporizer (PTV). The mass spectrometric detection was operated with full scan mode. The automated mass spectral deconvolution and identification system (AMDIS) and an isotopic internal standard were used for the qualitative and quantitative determination of the 32 pesticides, respectively. The conditions for PTV-large volume injection were studied. Furthermore, the selectivity and durability of the method were also assessed. Under the optimized conditions, the experimental results showed that all the linearities were good within their test ranges, with correlation coefficients more than 0. 995, and the method detection limits of the pesticides were 2.0-5.0 µg/kg. The spiked recoveries (n=6) at three levels in the 0. 010 - 0. 50 mg/kg using spinach, snap bean and cucumber samples as blank matrices were in the range of 65. 2% - 120. 3% with the relative standard deviations (RSDs) varying from 4. 1% to 22. 3%, showing good accuracy of the method. The advantages of the proposed method include high throughput, high sensitivity, reliability, robustness, and the ability to meet the demand of multi-residue pesticide analysis in fruits and vegetables.

Optimisation of Sample Preparation for Direct SPME-GC-MS Analysis of Murine and Human Faecal Volatile Organic Compounds for Metabolomic Studies

The analysis of volatile organic compounds (VOCs) emitted from biological fluids such as blood, urine, breath and faeces, has been receiving more attention from researchers and clinicians due to their contribution to the metabolome and potential use as diagnostic tools in clinical settings. The faecal metabolome represents the final product of a complex interaction involving the gut microbiota and cell metabolism and an accurate measurement of the faecal volatile organic metabolome enables a better understanding of disease-related metabolic pathways and, eventually, identifying potential biomarkers. However, there is a lack of published evidence evaluating the sample preparation steps for faecal metabolome analysis and no well-defined protocol has been established. Consequently, different research groups employ diverse methodologies, which, ultimately, prevent comparison of results between laboratories. We evaluated different aspects of sample preparation when processing murine and human faecal samples through a pipeline involving solid phase micro-extraction (SPME) coupled to gas chromatography-mass spectrometry (GC-MS). We identified the sample volume, the SPME fibre coating, the extraction conditions and the vial volume that produce the most accurate and reproducible results. Finally, we propose an optimized method for the direct SPME-GC-MS analysis of VOCs in murine and human faecal samples. To the best of our knowledge, this is the first work evaluating different aspects of sample preparation for direct SPME-GC-MS analysis of VOCs and the first method proposed for the analysis of murine and human faecal samples. In addition, our proposed method can be coupled to the Automated Mass Spectral Deconvolution and Identification System (AMDIS) and the R software package, Metab, in order to produce results in a reliable and high-throughput manner.

Composition and antimicrobial activity of root essential oil of Balkan endemic species Eryngium palmatum

The genus Eryngium L. (Apiaceae) with about 250 species is distributed all over the world. In Europe 26 species belong to this genus, while in Serbia five species are described: E. amethystinum L., E. planum L., E. campestre L., E. serbicum Pancic, and E. palmatum Pancic & Vis. [1, 2]. Species of this genus are used in traditional medicine for reproductive problems, against various inflammatory disorders, edema, sinusitis, and snake or scorpion bite [3]. Eryngium palmatum is a Balkan endemic species [1, 2]. Capetanos et al. obtained sesquicineole (21.3%), caryophyllene oxide (16.0%), spathulenol (16.0%), and sabinene (5.5%) as the main components in the essential oil of aerial parts of this plant [4]. The root essential oil of this endemic species and its antimicrobial activity were not previously investigated. Roots of E. palmatum were collected in Sicevacka Gorge, in Eastern Serbia in April 2007. Identification was confirmed by Dr. Marjan Niketic, curator botanist of the Natural History Museum, Belgrade, Serbia, and a herbarium specimen was deposited there (2007040201 BEO). The essential oil was obtained by hydrodistillation from air-dried and grounded herbal material in a Clevenger-type apparatus according to the procedure given in European Pharmacopoeia 7.0 [5]. The yield of the essential oil was calculated on a dry weight basis (w/w) after the evaporation of n-hexane. The root of E. palmatum yielded 0.06% (w/w) of yellow oil. The GC and GC/MS analyses were performed on an Agilent 7890A gas chromatograph equipped with a 5975 C inert XL EI/CI mass selective detector (MSD) and a flame ionization detector (FID). An HP-5MS capillary column (Agilent Technologies, 0.25 mm 30 m, 0.25 m film thickness) was used. GC oven temperature was programmed from 60C to 300C at a rate of 3C/min. Helium was used as carrier gas (constant pressure mode); inlet pressure 20.3 kPa; linear velocity 1 mL/min at 210C. Injector temperature 250C, injection mode split 50:1. Retention time was locked (RTL), lock compound was n-hexadecane with retention time 32.89 min. MS scan conditions: source temperature 230C; interface temperature 280C; EI mass spectra (70 eV) in the m/z range 35–550. The retention indices were experimentally determined using n-alkanes (C 8 –C 20 and C 21 –C 40 ) injected after the essential oil under the same chromatographic conditions. The identification of the compounds was based on the comparison of their retention indices (RI), their retention times (t R ), and mass spectra with those obtained from authentic samples and/or the NIST AMDIS (Automated Mass Spectral Deconvolution and Identification System) software, Wiley libraries, Adams database, and literature [6]. Relative percentages of the identified compounds were computed from the GC-FID peak area. 1 H NMR spectra were recorded on a Bruker Avance III 500 NMR spectrometer (500 MHz in CDCl 3 ) in 5 mm standard tubes. Chemical shifts are given on the scale relative to TMS as internal standard. IR spectrum of the pure essential oil was collected in the transmission mode on a Thermo Scientific Nicolet 6700 FT-IR spectrometer using a KBr capillary film in the Mid-IR range (4000–400 cm –1 ). In the E. palmatum root oil, 21 components were identified, amounting to 98.9% of the total oil (Table 1). The oil was characterized by a high percentage of saturated and unsaturated hydrocarbons (78.9%). Sesquiterpene hydrocarbons represented 13.8% of the total oil. The main components were polyacetylene (Z)-falcarinol (34.9%) and saturated aldehyde octanal (31.7%), followed by -curcumene (5.9%), 2,3,6-trimethyl benzaldehyde (5.4%), and heptanal (4.5%).