Identification of Volatiles in Tomato Fruit Using Headspace Solid-Phase-Micro-Extraction (HS-SPME) Coupled with Gas Chromatography-Mass Spectrometry (GC-MS).

Plant volatile organic compounds (VOCs) are organic chemicals that plants release as part of their natural biological processes. Various plant tissues produce VOCs, including leaves, stems, flowers, and roots. VOCs are essential in plant communication, defense against pests and pathogens, aroma and flavor, and attracting pollinators. The study of plant volatiles has become an increasingly important area of research in recent years, as scientists have recognized these compounds' important roles in plant physiology. As a result, there has been a growing interest in developing methods for collecting and analyzing plant VOCs. HS-SPME-GC-MS (headspace solid-phase microextraction-gas chromatography-mass spectrometry) is commonly used for plant volatile analysis due to its high sensitivity and selectivity. This chapter describes an efficient method for extracting and identifying volatile compounds by HS-SPME coupled with GC-MS in tomato fruits.

Solvent extraction and gas chromatography-mass spectrometric determination of probable carcinogen 1,4-dioxane in cosmetic products.

In the present work, a method based on solvent extraction and gas chromatography-mass spectrometry (GC-MS) has been validated for the determination of 1,4-dioxane in cosmetics. Various solvents including ethyl acetate, hexane, methanol, dichloromethane and acetone have been used for the extraction of 1,4-dioxane, among them the ethyl acetate was found to be the most efficient extracting solvent. This method has offered excellent quality parameters for instance linearity (R2 > 0.9991), limit of detection (LOD, 0.00065-0.00091 µg/mL), limit of quantification (LOQ, 0.00217-0.00304 µg/mL) and, precision intra-day (1.65-2.60%, n = 5) and inter-day (0.16-0.32%, n = 5) in terms of relative standard deviation (RSD%). A total of thirty-nine cosmetic samples of different brands and origin have been studied. Among them, the 1,4-dioxane was found in twenty-three samples (FB1-FB7, MC1-MC4, MC6-MC8, HS3, HS5, BL1-BL3, BL5 and PLD1-PLD3) at the levels between 0.15 µg/mL and 9.92 µg/mL, whereas in sixteen samples (MC5, HS1, HS2, SG1-SG5, BL4 and HP1- HP6) was found to be not detected. The recovery values were achieved between 93% and 99% in both low and high level of spiked samples. In comparison to the traditional analytical techniques, the proposed method was found to be very sensitive and cost-effective for the routine analysis of 1,4-dioxane at low concentration in cosmetics.

A High-Throughput Method for the Analysis of Erythrocyte Fatty Acids and the Omega-3 Index.

Omega-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) have several health benefits. In particular, low n-3 LCPUFA status is associated with cardiovascular disease (CVD) and led to the development of the omega-3 index that is the proportion of eicosapentaenoic acid and docosahexaenoic acid in the erythrocyte membranes, as a marker of CVD risk. Most methods used to measure the omega-3 index are laborious and time consuming. Therefore, the aim of this study was to develop a high-throughput method for the extraction and measurement of erythrocyte fatty acids and the omega-3 index. For sample extraction and quantification, two methods were used; a single-step extraction, degradation, and derivatization method by Lepage and Roy, followed by gas chromatography flame ionization detection (GC-FID), which is commonly used and a high-throughput method using an automated methyl tert-butyl ether extraction followed by electrospray ionization mass spectrometry. Both methods were first applied to the analysis of known concentrations of synthetic phospholipid (PL) mixtures to determine recovery and precision prior to their application in the analysis of human erythrocytes. The range of recoveries over five synthetic PL mixtures were 86.4-108.9% and the coefficient of variation was <10% (within-run) and ≤15.2% (between-run). Both methods showed high correlation (R = 0.993) for the omega-3 index and there was no systematic bias in the detection of omega-3 index using either method. The new high-throughput method described here offers considerable advantages in terms of simplicity and throughput compared to the GC-FID method and provides additional information on molecular PL concentrations.

A simple and economical method of gas chromatography-mass spectrometry to determine the presence of 6 pesticides in human plasma and its clinical application in patients with acute poisoning.

An economical, rapid, and sensitive method of gas chromatography-mass spectrometry (GC-MS) was developed and validated to determine the presence of six pesticides (dichlorvos, acetochlor, atrazine, chlorpyrifos, α-endosulfan, and ß-endosulfan) in human plasma. The pesticides were extracted with acetonitrile and concentrated using anhydrous sodium sulfate. Then, the target compounds were analyzed and quantified with GC-MS using borneol as an internal standard. Separation was performed on a HP-5MS capillary column (30 m × 0.25 mm × 0.25 µm) with temperature programming. Detection was accomplished under electro-spray ionization (ESI) in selected ion monitoring (SIM) mode. Under optimized conditions, satisfactory linear ranges of 0.05-10 µg/mL were obtained for all of the analyzed pesticides. The linear correlation coefficients were greater than 0.99. The average recovery was between 86.8 and 106.5%. The inter- and intra-day precision ranged from 1.7-14.5% and 4.2-13.8%, respectively. Dichlorvos was unstable in plasma both at room temperature and when frozen. The other five pesticides were stable after storage at - 20°C for 17 days and two freeze-thaw cycles. Thirty-five plasma samples from 15 patients with acute self-poisoning were analyzed using this method. Dichlorvos was found in 13 plasma samples with a mean concentration of 0.289 µg/mL, and atrazine was found in 6 with a mean concentration of 0.261 µg/mL. Acetochlor was found in one plasma sample (0.153 µg/mL). This method is simple, reliable and cost-effective. It takes little time and does not waste solvents, and it can be used to routinely detect six pesticides in patients with acute poisoning.

Gas chromatography-mass spectrometry determination of polycyclic aromatic hydrocarbons in baby food using QuEChERS combined with low-density solvent dispersive liquid-liquid microextraction.

A sensitive GC-MS method is reported for the determination of twelve polycyclic aromatic hydrocarbons (PAHs) in baby food. The sample preparation involves QuEChERS extraction combined with low-density solvent dispersive liquid-liquid microextraction (LDS-DLLME) and ultra-low temperature (-80 °C). Plackett-Burman screening design was employed to identify the main sample preparation variables that affect the extraction efficiency, such as the volume of toluene used in LDS-DLLME. The suitability of proposed method was verified by analytical selectivity, linearity in solvent and matrix-matched calibration curves and adequate recoveries (72-112%) and precision (RSD values ≤11%), under repeatability and within-laboratory reproducibility conditions. High analytical sensitivity was achieved for the monitoring of PAHs at the strict limit of 1 µg kg-1 fixed by the European Commission for baby foods. The validated method was applied to thirty-two commercial baby food samples, and the investigated PAHs were not detected in any sample.

A Technique for Thermal Desorption Analyses Suitable for Thermally-Labile, Volatile Compounds.

Many plant and insect interactions are governed by odors released by the plants or insects and there exists a continual need for new or improved methods to collect and identify these odors. Our group has for some time studied below-ground, plant-produced volatile signals affecting nematode and insect behavior. The research requires repeated sampling of volatiles of intact plant/soil systems in the laboratory as well as the field with the help of probes to minimize unwanted effects on the systems we are studying. After evaluating solid adsorbent filters with solvent extraction or solid phase micro extraction fiber sample collection, we found dynamic sampling of small air volumes on Tenax TA filters followed by thermal desorption sample introduction to be the most suitable analytical technique for our applications. Here we present the development and evaluation of a low-cost and relatively simple thermal desorption technique where a cold trap cooled with liquid carbon dioxide is added as an integral part of a splitless injector. Temperature gradient-based focusing and low thermal mass minimizes aerosol formation and eliminates the need for flash heating, resulting in low sample degradation comparable to solvent-based on-column injections. Additionally, since the presence of the cold trap does not affect normal splitless injections, on-the-fly switching between splitless and thermal desorption modes can be used for external standard quantification.

Rapid and simple procedure for the determination of cathinones, amphetamine-like stimulants and other new psychoactive substances in blood and urine by GC-MS.

In the last few years an increasing number of new psychoactive substances (NPS), with different chemical structures (of which 37% are stimulants), have been released into the illicit drug market. Their detection and identification in biological samples is hence of great concern. The aim of this work was to develop a high-throughput and rapid method for the determination of different classes of stimulants (amphetamine-type stimulants, cathinones, phenethylamines and ketamine analogues) from blood and urine samples using GC-MS. The proposed method allows the almost simultaneous derivatization and extraction of analytes from biological samples in a very short time, by using hexyl chloroformate as derivatization agent. The extraction of analytes was performed by Dispersive Liquid Liquid Microextraction (DLLME), a very rapid, cheap and efficient extraction technique that employs microliter amounts of organic solvents. The chromatographic method allowed for the separation of 26 stimulants including positional isomers (3-MMC and 4-MMC). The method was validated on urine and blood samples with the ability to detect and quantify all analytes with satisfactory limits of detection (LODs) ranging between 1 and 10ng/mL, limits of quantification (LOQs) between 2 and 50ng/mL, selectivity and linearity (5-1000ng/mL). The method was then applied to real samples from forensic cases, demonstrating its suitability for the screening of a wide number of stimulants in biological specimens.

Further improvements in pesticide residue analysis in food by applying gas chromatography triple quadrupole mass spectrometry (GC-QqQ-MS/MS) technologies.

Nowadays, the control of pesticide residues in food is well established. The capacity of triple quadrupole technology to satisfy the current food regulations has been demonstrated. However, the permanent high demand of consumers for more sensitive and faster testing is driving the development of improved analytical methodologies that increase the performances of sensitivity and robustness and reduce the analysis time. In this work, the feasibility of decreasing the run time to 12.4 min by modifying the oven temperature program, for a multiresidue method covering 203 pesticides, was evaluated. Satisfactory sensitivity results were achieved by reaching a limit of quantitation of 2 µg kg-1 for a great variety of fruits and vegetables. The validated method based on updated GC-QqQ-MS/MS has confirmed the abovementioned challenges with adequate robustness by its application to routine analyses for 69 real samples. The proposed method can represent great benefit for laboratories as it allows increasing samples throughput. It is also very useful for risk assessment studies, where the needs of low reporting limits and very wide analytical scope are necessary.

Development of a fast and cost-effective gas chromatography-mass spectrometry method for the quantification of short-chain and medium-chain fatty acids in human biofluids.

The quantification of short-chain and medium-chain fatty acids is becoming more and more relevant in fecal and plasma samples due to their biological impact, which has been associated with colon rectal cancer and fiber consumption. For these reasons, a fast, cost-effective, and reproducible analytical method is highly required. In this research, a gas chromatography-mass spectrometry method based on full scan and multiple reaction monitoring (MRM) acquisition modes were optimized and validated for the analysis of short-chain and medium-chain fatty acids in three biological samples: human fecal water, fecal fermentation supernatants, and human plasma. Several extraction solvents (acidified water, diethyl ether, dichloromethane, ethyl acetate, and methyl tert-butyl ether (MTBE) were further evaluated, demonstrating that the latter was clearly the most suitable solvent with recoveries from 75.4 to 124.4% and coefficient of variations lower than 20%. The applicability of the GC-MS method was tested, for instance, acetic acid was quantified by using samples of plasma and feces from healthy donors at mean values of 66.9 µM and 24.5 mM, respectively. The optimized protocol could successfully find applications within multi-compartment human studies. In parallel, a second pilot experiment on fecal fermentation supernatants indicated that the proposed protocol is suitable to follow the formation of SCFAs during in vitro fermentation by the human gut microbiota. In summary, the present work provided an improved GC-MS method for precise and accurate quantification of SCFAs and MCFAs in human feces and plasma.

Gas chromatography/negative chemical ionization mass spectrometry of transfluthrin in rat plasma and brain.

RATIONALE: Transfluthrin is a relatively non-toxic rapid-acting synthetic pyrethroid insecticide. It is widely used in household and hygiene products. A sensitive and accurate bioanalytical method is required for quantification of its concentration in plasma and its potential target organ, the brain for studies to assess its health effects and toxicokinetics in mammals. METHODS: The samples were prepared by liquid-liquid extraction. Gas chromatography mass spectrometry (GC/MS) analysis was performed for the determination of transfluthrin in biological samples with an overall method run time of 15 min. Transfluthrin was quantified using selected-ion monitoring (SIM) in the negative chemical ionization (NCI) mode. Chromatographic separation was achieved using a Zebron® ZB5-MS GC column operating with 1 mL/min constant flow helium. Cis-Permethrin was used as the internal standard. RESULTS: The method was validated to be precise and accurate within the linear range of 1.0-400.0 ng/mL in plasma and 4.0-400.0 ng/mL in brain homogenate, based on a 100 µL sample volume for both matrices. This method was applied to samples following administration of a 10 mg/kg oral dose to male adult rats. The plasma concentrations were observed to be 11.70 ± 5.69 ng/mL and brain concentrations 12.09 ± 3.15 ng/g when measured 2 h post-dose. CONCLUSIONS: A rapid GC/NCI-MS method was demonstrated to be sensitive, specific, precise and accurate for the quantification of transfluthrin in rat plasma and brain. The optimized method was successfully used to quantify the rat plasma and brain concentrations of transfluthrin 2 h after the oral dosing of Sprague-Dawley rats.

Novel fast analytical method for indirect determination of MCPD fatty acid esters in edible oils and fats based on simultaneous extraction and derivatization.

A novel method for indirect determination of MCPD esters levels in lipid samples has been developed. The method is based on combination of extraction and derivatization in the same sample preparation step. It is achieved by the application of diethyl ether as extraction solvent for isolation of analytes released from esterified forms from the water phase and as dilution solvent for solid PBA - the derivatization agent. It is a noteworthy improvement of recommended indirect approaches available in the literature because such steps as sample clean-up, multiple liquid-liquid extractions, and preconcentration are excluded in the proposed solution. In this way, the developed procedure is shortened and simplified. Such an approach also minimizes the utilization of organic solvents; therefore, it is in accordance with the principles of "green analytical chemistry." In spite of the fact that the step of sample clean-up is omitted, no deterioration in GC-MS system performance was observed. Equivalence testing of the developed procedure and AOCS cd 29b-13 official method (SGS) has been conducted. It was concluded that results obtained by both methods do not significantly differ statistically. The procedure has been applied to determination of MCPD esters concentrations in lipid fractions isolated by accelerated solvent extraction technique from such foodstuffs as bakery products, salty deep-fried snacks, and instant products. In all investigated samples, the level of bound MCPD was elevated. Additionally, for both procedures, the environmental impact (with the use of analytical Eco-scale) and uncertainty budget have been assessed and compared.

Simultaneous determination of multiclass pesticide residues in human plasma using a mini QuEChERS method.

Blood is one of the most assessable matrices for the determination of pesticide residue exposure in humans. Effective sample preparation/cleanup of biological samples is very important in the development of a sensitive, reproducible, and robust method. In the present study, a simple, cost-effective, and rapid gas chromatography-tandem mass spectrometry method has been developed and validated for simultaneous analysis of 31 multiclass (organophosphates, organochlorines, and synthetic pyrethroids) pesticide residues in human plasma by means of a mini QuEChERS (quick, easy, cheap, effective, rugged, and safe) method. We have adopted a modified version of the QuEChERS method, which is primarily used for pesticide residue analysis in food commodities. The QuEChERS method was optimized by use of different extraction solvents and different amounts and combinations of salts and sorbents (primary-secondary amines and C18) for the dispersive solid-phase extraction step. The results show that a combination of ethyl acetate with 2% acetic acid, magnesium sulfate (0.4 g), and solid-phase extraction for sample cleanup with primary-secondary amines (50 mg) per 1-mL volume of plasma is the most suitable for generating acceptable results with high recoveries for all multiclass pesticides from human plasma. The mean recovery ranged from 74% to 109% for all the analytes. The limit of quantification and limit of detection of the method ranged from 0.12 to 13.53 ng mL-1 and from 0.04 to 4.10 ng mL-1 respectively. The intraday precision and the interday precision of the method were 6% or less and 11% or less respectively. This method would be useful for the analysis of a wide range of pesticides of interest in a small volume of clinical and/or forensic samples to support biomonitoring and toxicological applications. Graphical Abstract Pesticide residues analysis in human plasma using mini QuEChERS method.

Determination of ß-hydroxy-ß-methylbutyrate concentration and enrichment in human plasma using chemical ionization gas chromatography tandem mass spectrometry.

Our objective was to develop a quick and simplified method for the determination of ß-Hydroxy-ß-methylbutyrate (HMB) and ɑ-ketoisocaproic acid (KIC) concentrations and enrichments by GC/MS/MS to determine the turnover rate of HMB in humans. In experiment 1, we provided a pulse of L-[5,5,5-2H3]leucine to younger adults in the postabsorptive state then collected blood samples over a 4h time period. In experiment 2, we provided a pulse of [3,4,methyl-13C3]HMB to older adults in the postabsorptive state then collected blood samples over a 3h time period. Plasma concentrations of KIC and HMB and MPE of KIC and HMB were determined by GC/MS/MS. Plasma enrichment of leucine was determined by LC/MS/MS. To determine plasma enrichment of [5,5,5-2H3]HMB and [3,4,methyl-13C3]HMB, samples were derivatized using pentafluorobenzyl bromide and analyzed using chemical ionization mode. The final methods used included multiple reaction monitoring of transitions 117.3>59.3 for M+0 and 120.3>59.3 for M+3. In experiment 1, peak MPE of Leu peaked at 9.76% generating a peak MPE of KIC at 2.67% and a peak HMB MPE of 0.3%. In experiment 2, the rate of appearance for HMB was 0.66µmol/kg ffm/h. We calculated that production of HMB in humans accounts for 0.66% of total leucine turnover.

Determination of red blood cell fatty acid profiles: Rapid and high-confident analysis by chemical ionization-gas chromatography-tandem mass spectrometry.

Cellular fatty acid (FA) profiles have been acknowledged as biomarkers in various human diseases. Nevertheless, common FA analysis by gas chromatography mass spectrometry (GC-MS) requires long analysis time. Hence, there is a need for feasible methods for high throughput analysis in clinical studies. FA was extracted from red blood cells (RBC) and derivatized to fatty acid methyl esters (FAME). A method using gas chromatography tandem mass spectrometry (GC-MS/MS) with ammonia-induced chemical ionization (CI) was developed for the analysis of FA profiles in human RBC. We compared this method with classical single GC-MS using electron impact ionization (EI). The FA profiles of 703 RBC samples were determined by GC-MS/MS. In contrast to EI ammonia-induced CI resulted in adequate amounts of molecular ions for further fragmentation of FAME. Specific fragments for confident quantification and fragmentation were determined for 45 FA. The GC-MS/MS method has a total run time of 9min compared to typical analysis times of up to 60min in conventional GC-MS. Intra and inter assay variations were <10% for all FA analyzed. Analysis of RBC FA composition revealed an age-dependent increase of the omega-3 eicosapentaenoic and docosahexaenoic acid, and a decline of the omega-6 linoleic acid with a corresponding rise of the omega-3 index. The combination of ammonia-induced CI and tandem mass spectrometry after GC separation allows for high-throughput, robust and confident analysis of FA profiles in the clinical laboratory.

In vitro steroid profiling system for the evaluation of endocrine disruptors.

Endocrine disruptors (ED) are chemicals that affect various aspects of the endocrine system, often leading to the inhibition of steroidogenesis. Current chemical safety policies that restrict human exposure to such chemicals describe often time-consuming and costly methods for the evaluation of ED effects. We aimed to develop an effective tool for accurate phenotypic chemical toxicology studies. We developed an in vitro ED evaluation system using gas chromatography/mass spectrometry (GC/MS/MS) methods for metabolomic analysis of multi-marker profiles. Accounting for sample preparation and GC/MS/MS conditions, we established a screening method that allowed the simultaneous analysis of 17 steroids with good reproducibility and a linear calibration curve. Moreover, we applied the developed system to H295R human adrenocortical cells exposed to forskolin and prochloraz in accordance with the Organization for Economic Cooperation and Development (OECD) guidelines and observed dose-dependent variations in steroid profiles. While the OECD guidelines include only testosterone and 17ß-estradiol, our system enabled a comprehensive and highly sensitive analysis of steroid profile alteration due to ED exposure. The application of our ED evaluation screen could be economical and provide novel insights into the hazards of ED exposure to the endocrine system.

Comprehensive Urine Drug Screen by Gas Chromatography/Mass Spectrometry (GC/MS).

Drug screening is an essential component of clinical toxicology laboratory service. Some laboratories use only automated chemistry analyzers for limited screening of drugs of abuse and few other drugs. Other laboratories use a combination of various techniques such as immunoassays, colorimetric tests, and mass spectrometry to provide more detailed comprehensive drug screening. Mass spectrometry, gas or liquid, can screen for hundreds of drugs and is often considered the gold standard for comprehensive drug screening. We describe an efficient and rapid gas chromatography/mass spectrometry (GC/MS) method for comprehensive drug screening in urine which utilizes a liquid-liquid extraction, sample concentration, and analysis by GC/MS.

Fast determination of hydroxylated polychlorinated biphenyls in human plasma by online solid phase extraction coupled to liquid chromatography-tandem mass spectrometry.

Hydroxylated polychlorinated biphenyls (OH-PCBs) have been shown to be strongly retained in human blood causing endocrine-related toxicity, particularly on the thyroid system. Traditionally, analytical methods for the determination of OH-PCBs require labor-intensive and long-time consuming sample preparation with several extraction, evaporation and cleanup procedures steps and, in some cases, derivatization prior to the analysis by gas or liquid chromatography-mass spectrometry (GC-MS or LC-MS). The present study developed and validated a novel, sensitive and high throughput online solid phase extraction (SPE) method coupled to LC-tandem mass spectrometry (MS/MS) for the separation and quantitation of relevant congeners of OH-PCBs in human plasma. The developed method presented limits of quantification (LOQ) ranging from 0.02 to 0.5 ng mL(-1) and extraction recoveries from 71 to 134% for all congeners, requiring small amount of sample (only 100 µL) and minimal sample preparation. In order to evaluate the applicability of the method, preliminary tests (N = 93) were conducted in plasma from individuals occupationally exposed to very high levels of PCBs in a German cohort. Penta-through hepta-chlorinated OH-PCBs were the predominant congeners in human plasma with concentrations up to 44.5 ng mL(-1), while lower chlorinated OH-PCBs were occasionally detected. In addition, a new PCB 28 metabolite has been synthesized and identified for the first time in human plasma and associations between OH-PCBs and their parent compounds in the studied cohort were also assessed.

LC-MS/MS-based quantification of cholesterol and related metabolites in dried blood for the screening of inborn errors of sterol metabolism.

Smith-Lemli-Opitz syndrome (SLOS) is an inherited metabolic disease in the cholesterol biosynthesis pathway which is characterised by accumulation of 7- and 8-dehydrocholesterol and by reduced cholesterol concentrations in all tissues and body fluids. With this study, we developed a new, rapid, robust and high-throughput tandem mass spectrometric method as routine application for the selective SLOS screening and therapy monitoring in serum and dried blood. After protein precipitation of 10 µL serum or 4.7 mm dried blood spot, the sum of 7- and 8-dehydrocholesterol (DHC) was analysed by rapid chromatography combined with tandem mass spectrometry. Method comparison with GC-MS was performed for 46 serum samples. A comparison between serum and corresponding dried blood spots for DHC and cholesterol was performed with 40 samples from SLOS patients. Concentrations of DHC and cholesterol were analysed in 2 dried blood samples from newborns with SLOS and 100 unaffected newborns. Intra- and inter-assay variabilities ranged between 3.7 and 17.7% for serum and dried blood spots. Significant correlations between the new LC-MS/MS method and GC-MS were determined for DHC (r = 0.937, p < 0.001) and for cholesterol (r = 0.946, p < 0.001). Significant coefficients of correlation between serum and dried blood spot samples above 0.8 were calculated for both analytes. A cut-off value of 5.95 for the ratio of DHC/cholesterol (multiplied by 1000) was found to distinguish newborns diagnosed with SLOS from normal newborns in a retrospective analysis after 5 years. The developed method enables a rapid quantification of the sum parameter 7- and 8-DHC in newborns and SLOS patients under therapy in serum as well as dried blood spot samples.

Application of gas chromatography/flame ionization detector-based metabolite fingerprinting for authentication of Asian palm civet coffee (Kopi Luwak).

Development of authenticity screening for Asian palm civet coffee, the world-renowned priciest coffee, was previously reported using metabolite profiling through gas chromatography/mass spectrometry (GC/MS). However, a major drawback of this approach is the high cost of the instrument and maintenance. Therefore, an alternative method is needed for quality and authenticity evaluation of civet coffee. A rapid, reliable and cost-effective analysis employing a universal detector, GC coupled with flame ionization detector (FID), and metabolite fingerprinting has been established for discrimination analysis of 37 commercial and non-commercial coffee beans extracts. gas chromatography/flame ionization detector (GC/FID) provided higher sensitivity over a similar range of detected compounds than GC/MS. In combination with multivariate analysis, GC/FID could successfully reproduce quality prediction from GC/MS for differentiation of commercial civet coffee, regular coffee and coffee blend with 50 wt % civet coffee content without prior metabolite details. Our study demonstrated that GC/FID-based metabolite fingerprinting can be effectively actualized as an alternative method for coffee authenticity screening in industries.

Comparative assessment of three cleanup procedures after QuEChERS extraction for determination of trichothecenes (type A and type B) in processed cereal-based baby foods by GC-MS.

A QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method was optimized and validated for the simultaneous extraction of 12 trichothecenes (type A and type B) from baby foods, followed by gas chromatography-mass spectrometry (GC-MS) analysis. Using this methodology, limits of detection and quantification ranging from 0.37 to 19.19 µg/kg and 1.24 to 63.33 µg/kg, respectively, were achieved. Mean recoveries between 44% and 135% were obtained and repeatability, expressed as relative standard deviation, was always lower than 29%. A comparison between the developed method and two alternative cleanup procedures (MultiSep and IAC--immunoaffinity columns) was performed, being the advantages and drawbacks of each one presented. The screening of nine commercially available cereal-based baby foods revealed the presence of 4 out of 12 studied trichothecenes: DON (deoxynivalenol), 15AcDON (15-acetyl-deoxynivalenol), T2-Tetrol and NEO (Neosolaniol). DON was the most commonly found, being detected in 4 samples in significant levels (29-270 µg/kg), sometimes exceeding the maximum permitted level. 15AcDON, T2-Tetrol and NEO were found only in one sample each.