Gas Chromatography-triple Quadrupole Tandem Mass Research Articles

Mitigation of multiple pesticide residues in green bell pepper using natural extracts as an emerging trend in pesticide decontamination using GC–MS/MS

AbstractThe main objective of this work is to assess the effect of natural extracts and its characterization for the mitigation of multiple pesticide residues in green bell pepper. In this study, four plant extracts such as Acacia concinna, Albizia amara, Tamarindus indica, and Azadirachta indica have been used to mitigate the six pesticides present in green bell pepper and its phytochemical constituents were analyzed using gas chromatography coupled to triple quadrupole tandem mass spectrometry (GC–MS/MS). In addition to that, the method for the quantification of six pesticide residues in green bell pepper using GC–MS/MS was validated according to SANTE/11312/2021 guidelines. The extracts of Acacia concinna, Albizia amara, Tamarindus indica, and Azadirachta indica were showed effective mitigation for selected pesticides. The phytochemical compounds present in plant extracts were correlated with its effect on the mitigation of multiple pesticide residues. The T. indica showed better pesticide mitigation efficiency when compared to A. indica, A. amara, and A. concinna, respectively. The plant extracts showed higher mitigation efficiency for organophosphorous pesticides than the synthetic pyrethroids. The nutritional and sensorial properties of green bell pepper were highly retained after pesticide decontamination using plant extracts. The results of this work indicated the application of plant extracts for the mitigation of multiple pesticides in green bell pepper by household and commercial processing units. This study addressed the balance between food safety and food quality.Practical ApplicationsPesticide contamination in vegetables is one of the major global food safety issues and it poses potent threat to human health. Pesticide decontamination is always a challenging task due to the unpredictability of types and levels of pesticides and the presences of multiple pesticides in contaminated vegetables. Washing of vegetables with water is the common procedure followed by both household and commercial units. However, washing of vegetables only with water is not enough to reduce the multiple pesticides residues to safe levels. The washing of vegetables with chemical solutions and other thermal and non‐thermal processing could result in toxic byproduct formation based on the types of pesticides present in contaminated sample. Hence, in this study, the plant extracts were characterized for its efficiency on the mitigation of multiple pesticide residues in vegetables has been analyzed by Gas Chromatography—Triple Quadrupole Tandem Mass Spectrometry and the method has been validated according to SANTE/11312/2021 guidelines. The phytochemical compounds of the plant extracts could be correlated with the effective multiple pesticide decontamination efficiency and the plant extracts were found to retain the physicochemical properties of vegetables during washing. The results of this study showed that the selected plant extracts could enhance the food safety without compromising food quality. The results of this study could be useful for the formulation of vegetables cleaning solutions for the effective mitigation of multiple pesticide residues.

High-throughput analytical methodology of monoalkyl phthalate esters and the composite risk assessment with their parent phthalate esters in aquatic organisms and seawater

A sensitive, robust, and highly efficient analytical methodology involving solid phase extraction coupled to ultra-high performance liquid chromatography tandem mass spectrometry was successfully established to detect 13 monoalkyl phthalate esters (MPAEs) in aquatic organisms and seawater. After the organisms were preprocessed using enzymatic deconjugation with β-glucuronidase, extraction, purification, and qualitative and quantitative optimization procedures were performed. Under optimal conditions, the limits of detection varied from 0.07 to 0.88 μg/kg (wet weight) and 0.04–1.96 ng/L in organisms and seawater, respectively. Collectively, MPAEs achieved acceptable recovery values (91.0–102.7%) with relative standard deviations less than 10.4% and matrix effects ranging from 0.93 to 1.07 in the above matrix. Furthermore, MPAEs and phthalate esters were detected by the developed methodology and gas chromatography-triple quadrupole tandem mass spectrometer in practical samples, respectively. Mono-n-butyl phthalate and mono-iso-butyl phthalate were the most predominant congeners, accounting for 24.8–35.2% in aquatic organisms and seawater. Comprehensive health and ecological risks were higher after the MPAEs were incorporated than when phthalate esters were considered separately, and greater than their risk threshold. Therefore, the risks caused by substances and their metabolites in multiple media, with analogous structure-activity relationships, should be considered to ensure the safety of aquatic organisms and consumers.

Prenatal exposure to pesticides and domain-specific neurodevelopment at age 12 and 18 months in Nanjing, China

BackgroundThe extensive usage of pesticides has led to a ubiquitous exposure in the Chinese general population. Previous studies have demonstrated developmental neurotoxicity associated with prenatal exposure to pesticides. ObjectivesWe aimed to delineate the landscape of internal pesticides exposure levels from pregnant women’s blood serum samples, and to identify the specific pesticides associated with the domain-specific neuropsychological development. MethodsParticipants included 710 mother-child pairs in a prospective cohort study initiated and maintained in Nanjing Maternity and Child Health Care Hospital. Maternal spot blood samples were collected at enrollment. Leveraging on an accurate, sensitive and reproducible analysis method for 88 pesticides, a total of 49 pesticides were measured simultaneously using gas chromatography-triple quadrupole tandem mass spectrometry (GC–MS/MS). After implementing a strict quality control (QC) management, 29 pesticides were reported. We assessed neuropsychological development in 12-month-old (n = 172) and 18-month-old (n = 138) children using the Ages and Stages Questionnaire (ASQ), Third Edition. Negative binomial regression models were used to investigate the associations between prenatal exposure to pesticides and ASQ domain-specific scores at age 12 and 18 months. Restricted cubic spline (RCS) analysis and generalized additive models (GAMs) were fitted to evaluate non-linear patterns. Longitudinal models with generalized estimating equations (GEE) were conducted to account for correlations among repeated observations. Weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) were applied to examining the joint effect of the mixture of pesticides. Several sensitivity analyses were performed to assess the robustness of the results. ResultsWe observed that prenatal exposure to chlorpyrifos was significantly associated with a 4 % decrease in the ASQ communication scores both at age 12 months (RR, 0.96; 95 % CI, 0.94–0.98; P < 0.001) and 18 months (RR, 0.96; 95 % CI, 0.93–0.99; P < 0.01). In the ASQ gross motor domain, higher concentrations of mirex (RR, 0.96; 95 % CI, 0.94–0.99, P < 0.01 for 12-month-old children; RR, 0.98; 95 % CI, 0.97–1.00, P = 0.01 for 18-month-old children), and atrazine (RR, 0.97; 95 % CI, 0.95–0.99, P < 0.01 for 12-month-old children; RR, 0.99; 95 % CI, 0.97–1.00, P = 0.03 for 18-month-old children) were associated with decreased scores. In the ASQ fine motor domain, higher concentrations of mirex (RR, 0.98; 95 % CI, 0.96–1.00, P = 0.04 for 12-month-old children; RR, 0.98; 95 % CI, 0.96–0.99, P < 0.01 for 18-month-old children), atrazine (RR, 0.97; 95 % CI, 0.95–0.99, P < 0.001 for 12-month-old children; RR, 0.98; 95 % CI, 0.97–1.00, P = 0.01 for 18-month-old children), and dimethipin (RR, 0.94; 95 % CI, 0.89–1.00, P = 0.04 for 12-month-old children; RR, 0.93; 95 % CI, 0.88–0.98, P < 0.01 for 18-month-old children) were associated with decreased scores. The associations were not modified by child sex. There was no evidence of statistically significant nonlinear relationships between pesticides exposure and RRs of delayed neurodevelopment (Pnonlinearity > 0.05). Longitudinal analyses implicated the consistent findings. ConclusionThis study gave an integrated picture of pesticides exposure in Chinese pregnant women. We found significant inverse associations between prenatal exposure to chlorpyrifos, mirex, atrazine, dimethipin and the domain-specific neuropsychological development (i.e., communication, gross motor and fine motor) of children at 12 and 18 months of age. These findings identified specific pesticides with high risk of neurotoxicity, and highlighted the need for priority regulation of them.

Contamination level and population exposure assessment of chloropropanol esters in edible vegetable oil in Shandong Province from 2016 to 2020

To investigate the contamination of 2-chloropropanol esters and 3-chloropropanol esters in commercial edible vegetable oils in Shandong Province, and to assess the dietary 3-chloropropanol esters exposure and the health risk of intaking 3-chloropropanol esters. From 2016 to 2020, 406 individually packaged edible vegetable oils were collected from stores and farmers&apos; markets in 16 prefecture-level cities in Shandong Province. According to the 2016 National Food Contamination and Harmful Factors Risk Monitoring Manual, using gas chromatography-triple quadrupole tandem mass spectrometry detection, isotope internal standard method for quantification, laboratory determination of 2-chloropropanol ester and 3-chloropropanol in vegetable oil ester content. Combined with population weight, oil consumption and monitoring data, the point assessment method was used to evaluate the exposure of residents in Shandong Province to 3-chloropropanol esters. The detection rate of 3-chloropropanol ester was 92.4%(375/406), the concentration range was&lt;limit of detection(LOD)-18.4 mg/kg, the median was 0.470 mg/kg, the average was 0.833 mg/kg, and the maximum value was 18.4 mg/kg in rice oil; the detection rate of 2-chloropropanol ester was 88.7%(360/406), the concentration range was &lt;LOD-8.46 mg/kg, the median value was 0.204 mg/kg, the average value was 0.432 mg/kg, and the maximum value was 8.46 mg/kg in rice oil. The average exposure of each age group was less than the tolerable daily intake, and the high-end exposure of the children(2-6 years old) and adolescents(7-10 years old) group was greater than the tolerable daily intake. The contamination of chloropropanol esters of edible vegetable oil in Shandong Province from 2016 to 2020 is widespread, and the highest detection value appears in rice oil. Children(2-6 years old) and adolescents(7-10 years old) in high-risk situations ingest 3-chloropropanol esters present health risks.

The variation of odor characteristics of wastewater sludge treated by advanced anaerobic digestion (AAD) and the contribution pattern of key odorants

Identification of the odor characteristics of wastewater sludge is important in the evaluation of sludge quality and disposal options considering that sludge odor nuisance may cause major environmental issues. In this study, raw sludge and sludge cake were collected from five WWTPs applied advanced anaerobic digestion (AAD) sludge treatment process to clarify the variation of odor characteristics using sensory analysis and instrumental analysis. The electronic nose, gas chromatography-ion mobility spectrometry (GC-IMS) and gas chromatography-triple quadrupole tandem mass spectrometry (GC–MS/MS) were used to profile and identify the chemical composition of key odorants. A total of 20 odorants were identified and quantified, including 6 groups of chemicals, among which volatile sulfur compounds (VSCs), indole, 3-methylindole and geosmin were identified as key odorants. The odor of the dewatered digested sludge was improved by means of changing the odor character from fecal/sulfide to earthy odor due to the reduction in VSCs concentration. The AAD and subsequent dewatering process resulted in effective removal of VSCs, which are important constituents that impact the sludge odor characteristics through synergistic effect on fecal odorants and masking effect on earthy odorants. Moreover, due to the variation of sludge quality after AAD treatment, the emission capacity of indole, 3-methylindole, and other volatiles increased, which could not be neglected for the formation of unique sludge odor.

Carbon Isotope Composition and Geochemical Features of Sediments From Gongga Mountain, China, and Potential Environmental Implications

Using gas chromatography-triple quadrupole tandem mass spectrometry (GC-MS/MS), the soluble organic matter was analyzed for the first time in twenty-two sediment samples from the eastern slopes of the Gongga Mountain, China, at high altitudes between 4,600 and 6,700 m. The C11-C33n-alkanes and C9-C33n-alkan-2-ones were identified in these samples. Both compounds were dominated by odd carbon numbers in the long-chain molecules and contained a maximum of n-C27 or n-C29, indicating that the sediments were predominantly of higher plant origin. However, the short-chain n-alkan-2-ones, with a maximum content of n-C17 or i-C18 (phytone, 6, 10, 14-trimethylpentadecan-2-one), did not show a predominance of odd and even numbers, suggesting that they were predominantly derived from bacteria and algae. Therefore, we suggest that the organic matter in Gongga Mountain comes from three sources, i.e. bacteria, algae, and higher plants. Stable carbon isotope (δ13C) values ranged from −24.6‰ to −27.3‰, indicating that C3 plants were the dominant organic input to the sediments and suggesting a relatively colder and drier depositional environment. However, C4 plants increase sharply at high altitudes of 6,300–6,600 m, suggesting that the paleoclimate of Gongga Mountain became drier and wetter with the increase of altitude.

Characterization of aroma-active compounds in Dongli by quantitative descriptive analysis, gas chromatography-triple quadrupole tandem mass spectrometry, and gas chromatography-olfactometry.

The online version contains supplementary material available at 10.1007/s13197-022-05463-8.

Simultaneous focused ultrasound solid–liquid extraction and dispersive solid-phase extraction clean-up for gas chromatography–tandem mass spectrometry determination of polycyclic aromatic hydrocarbons in crustacean gammarids meeting the requirements of the European Union Water Framework Directive

The study presents the development and validation of a method for the determination of seven priority polycyclic aromatic hydrocarbons (PAHs, including fluoranthene and benzo[a]pyrene, for which the EU has set environmental quality standards, EQS, for biota) in gammarid samples combining focused ultrasound solid–liquid extraction and dispersive solid-phase extraction clean-up in one step followed by gas chromatography–triple quadrupole tandem mass spectrometry (GC–QqQ-MS/MS). The method is designed to analyse small about 100 mg dry weight (dw) samples obtained after lyophilisation of 500 mg wet weight (ww) samples. The sample preparation procedure is simple, environment friendly (method was classified as “an excellent green analysis” according to the analytical Eco-Scale assessment), non-laborious and low-cost and, apart from the sample extract concentration step, is quick. Thorough disintegration of the gammarids is achieved by a combination of sonication and the addition of granular anhydrous Na2SO4 to the gammarid suspension, thus avoiding the need to grind the sample prior to analysis. The QqQ-MS/MS detector, thanks to its excellent selectivity and sensitivity, allows to meet the EQS requirements for PAHs in biota with a good margin (limits of quantification in the range of 0.12 and 0.56 ng g‒1 ww). The method has been successfully validated (in terms of linearity, method limits, precision, trueness, robustness, measurement uncertainty and comparative analysis of real samples), and has been shown to be suitable for monitoring and evaluating the PAHs contamination in surface water biota.

A facile molecularly imprinted column coupled to GC-MS/MS for sensitive and selective determination of polycyclic aromatic hydrocarbons and study on their migration in takeaway meal boxes

The analysis of toxic and harmful substances in food has attracted significant attention. In this work, a molecularly imprinted column coupled to gas chromatography-triple quadrupole tandem mass spectrometry method (MIC-GC-MS/MS) method for the determination of 16 polycyclic aromatic hydrocarbons (PAHs) in takeaway meal boxes was established by comparing the extraction results of 16 PAHs with 5 different sample pretreatment techniques, and the effects of food types and storage conditions on the migration of PAHs was studied by migration test. The conditions of extraction and chromatography-mass spectrometry were optimized. The results showed that the linear ranges were in the wide range of 1–100 ng mL−1 for 16 PAHs, with the correlation coefficients (R) higher than 0.9983; the detection limits (LODs) and the limits of quantification (LOQs) were in the range of 0.08–0.42 μg kg−1 and 0.24–1.26 μg kg −1, respectively; the spiked recoveries at three levels of 10, 20, 30 μg kg−1 were in the range of 86.2%–107.7% with the relative standard deviation (RSD) less than 7.8%. Therefore, this method had high sensitivity and good reproducibility and was suitable for the determination of 16 PAHs in food contact materials. The migration test of PAHs showed that the migration amount of PAHs in takeaway meal boxes was closely related to food types, and the migration amount was positively correlated with contact temperature and contact time in a certain range.

Pollution Characteristics and Risk Assessment of Nitrated Polycyclic Aromatic Hydrocarbons in the Atmosphere of Guangdong-Hong Kong-Macao Greater Bay Area

To investigate the pollution characteristics and sources of nitrated polycyclic aromatic hydrocarbons (NPAHs) in Guangdong-Hong Kong-Macao Greater Bay Area (GBA), 44 ambient air samples were collected using the active sampling method, which were then determined via gas chromatography-triple quadrupole tandem mass spectrometry. The main results showed that filters, polyurethane foam, and XAD-2 resin were the essential materials for sampling NPAHs in ambient air in order to characterize the pollution status accurately. The levels of ρ(Σ18NPAHs) in ambient air at GBA ranged from 162 pg·m-3 to 2094 pg·m-3, and the average levels of ρ(Σ18NPAHs) were (675±430) pg·m-3 in summer and (637±349) pg·m-3 in winter. NPAHs were widely found in the ambient air of GBA and were dominated by 1-nitronaphthalene (220 pg·m-3), 2-nitronaphthalene (146 pg·m-3), 9-nitroanthracene (105 pg·m-3), and 2-nitrofluoranthene (72 pg·m-3). The congener profile characteristics of NPAHs in summer and winter were similar. The gas/particle partitioning characteristics of NPAHs revealed that dicyclic and tricyclic NPAHs tend to occur in the gas phase, and tetracyclic NPAHs tend to be adsorbed in the particle phase. The fraction of NPAHs concentrations in the particulate fraction of their total atmospheric concentrations increased with the increase in their molecular weight. In winter, NPAHs tend to be adsorbed in the particle phase, whereas in summer, NPAHs tend to exist in the gas phase. Based on the ratios of characteristic pollutants, in both the summer and winter season, photochemical reactions were the main source of NPAHs in the atmosphere of GBA and were primarily generated by the reaction of the hydroxyl radical in the daytime. The carcinogenic risk value calculation showed that the current carcinogenic risk of NPAHs in the ambient air of GBA was controllable.

Method Development for Determination of Polyhalogenated Carbazoles in Industrial Waste Through Gas Chromatography-Triple Quadrupole Tandem Mass Spectrometry

Method Development for Determination of Polyhalogenated Carbazoles in Industrial Waste Through Gas Chromatography-Triple Quadrupole Tandem Mass Spectrometry

Miniaturized QuEChERS based sample preparation method combined with gas chromatography–tandem mass spectrometry for the determination of selected polycyclic aromatic hydrocarbons in crustacean gammarids

The study presents a new miniaturized and low-cost sample preparation method combined with gas chromatography–triple quadrupole tandem mass spectrometry (GC–QqQ-MS/MS) analysis developed to determine selected polycyclic aromatic hydrocarbons (PAHs: (naphthalene – Nap, acenaphthene – Ace, anthracene – Ant, fluoranthene – Flu, and benzo[a]pyrene – BaP) in dried gammarid samples. The sample preparation involved modification of the so-called QuEChERS (stands for quick, easy, cheap, effective, rugged, and safe) method followed by use of a novel combination of dispersive liquid–liquid microextraction (DLLME) and treatment with H2SO4 solution, which allowed further purification and concentration of the extract and solvent exchange without the need for solvent evaporation. The QqQ-MS/MS detector operating in the pseudo-MRM mode was used to detect PAHs with increased sensitivity compared to the classical quadrupole MRM technique. The method was validated in terms of linearity and range, detection and quantification limits (LOD and LOQ), matrix effect, recovery and precision for the analysis of 200 mg samples of dried freshwater shrimps Gammarus pulex. The LOQs for the target PAHs ranged from 4.7 to 6.3 ng g−1 dw (dry weight) or after applying the conversion factor of 0.2 (dw/ww) from 0.94 to 1.3 ng g−1 ww (wet weight). The recovery for all the analytes was in the range 72–104% and repeatability (precision) expressed by relative standard deviation in the range 1–10%. The developed method has been shown to be suitable for the purpose of monitoring and controlling compliance with environmental quality standards (EQS, set by the EU) for Flu and BaP in surface water biota.

Simultaneous determination of 11 volatile perfluorinated compound precursors in textiles using gas chromatography-triple quadrupole mass spectrometry

以甲醇为提取溶剂,超声辅助提取纺织品中的全氟化合物前体物,建立了一种气相色谱-三重四极杆质谱(GC-MS/MS)法同时测定纺织品中11种挥发性全氟化合物前体物:4种氟调聚物醇(FTOHs)、3种氟调聚丙烯酸酯(FTAs)、2种全氟辛基磺酰胺(FOSAs)和2种全氟辛基磺酰胺乙醇(FOSEs)。考察了超声提取溶剂、提取温度和提取时间对提取效率的影响,最终确定用甲醇为提取溶剂,70 ℃下超声提取60 min,目标物经VF-WAXms毛细管柱(30 m×0.25 mm×0.25 μm)程序升温分离,GC-MS/MS多反应监测(MRM)模式检测,外标法定量。实验结果表明:11种挥发性全氟化合物前体物在10~500 μg/L范围内线性关系良好,相关系数(r)均不低于0.9984;以信噪比为3计算,检出限(LOD)为0.002~0.04 mg/kg;以信噪比为10计算,定量限(LOQ)为0.006~0.1 mg/kg;不同材质纺织品中,11种挥发性全氟化合物前体物在高、中、低3个添加水平下的回收率为73.2%~117.2%,相对标准偏差(RSD)为0.1%~9.4%(n=6)。该方法前处理简单,定性、定量准确,灵敏度高,重现性好,可有效用于纺织品中11种挥发性全氟化合物前体物的同时检测。实际样品分析发现,当前全氟化合物前体物已被应用于纺织品整理当中。该方法的建立对我国纺织品中全氟化合物前体物风险物质的管控和检测标准的制定具有一定的理论和现实意义。

Determination of polyhalogenated carbazoles in soil using gas chromatography-triple quadrupole tandem mass spectrometry

Polyhalogenated carbazoles (PHCZs) are emerging environmental contaminants that have caused wide concerns due to their dioxin-like toxicity and environmental persistence. It would be desirable to determine all of these chemicals using a simple analytical method. Within this study, a simple and sensitive method combining accelerated solvent extraction (ASE) with gas chromatography-triple quadrupole tandem mass spectrometry (GC–MS/MS) was established to simultaneously analyze eleven frequently detected PHCZs in soil, including CCZ-3, CCZ-36, CCZ-1368, CCZ-2367, BCZ-3, BCZ-27, BCZ-36, BCZ-136, BCZ-1368, 1-B-36-CCZ, 18-B-36-CCZ. The calibration curves of the target analytes showed good linearity (R2 > 0.99, level = 6), and method detection limits (MDLs) ranging from 1.5 to 14.6 pg g−1. The average recoveries of the analytes in soil samples ranged from 64% to 126% with the RSD ranging from 2.0% to 10%. The developed method was successfully used for determination of these eleven PHCZs in soil samples from a tie-dye area in southwest China. Total concentrations of these eleven PHCZs ranging up to 46.3 ng g−1 dw. CCZ-36, BCZ-3, CCZ-3, 1-B-36-CCZ, 18-B-36-CCZ, and BCZ-1368 were the most abundant compounds in soil.

Optimization and validation of headspace solid-phase microextraction method coupled with gas chromatography-triple quadrupole tandem mass spectrometry for simultaneous determination of volatile and semi-volatile organic compounds in coking wastewater treatment plant.

Industrial wastewater could be an important source for the emission of volatile (VOCs) and semi-volatile organic compounds (SVOCs), but little is known about it. In this study, a method for the identification and quantitation of 43 VOCs and SVOCs in coking wastewater was developed using a solvent-free equilibrium extraction method on the basis of headspace solid-phase microextraction accompanied by gas chromatography-triple quadrupole tandem mass spectrometry (HS-SPME-GC-MS/MS). To ensure good extraction efficiency, the parameters that have an effect on the HS-SPME-GC-MS/MS process were carefully optimized, in terms of fiber exposure time and temperature, pH, salt additives, sample volume, and desorption time. The HS-SPME method showed good linearity range with coefficients of determination (R2) ≥ 0.991 and achieving a satisfactory recoveries value (70-120%) with good relative standard deviations (RSDs) < 20% (precision). Furthermore, the purposed approach proved to be sensitive with low detection limits, where the values ranged from 0.03 to 3.01μg/L. The real sample analysis result showed that 43 of VOCs and SVOCs were detected in raw coking wastewater, with 3-cresol as the dominant ones. Further, the method revealed that seven phenols, 11 polycyclic aromatic hydrocarbons, and five BTEX were detected even in the treated effluent. In conclusion, the HS-SPME method developed in this study is simple in sample preparation, convenient, sensitive, and could satisfy the requirement of the analysis of VOCs and SVOCs in coking wastewater.

Validation Including Uncertainty Estimation of a GC–MS/MS Method for Determination of Selected Halogenated Priority Substances in Fish Using Rapid and Efficient Lipid Removing Sample Preparation

A rapid method is proposed for the determination of selected H2SO4 stable organic compounds—eight organochlorines (OCs; hexachloro-1,3-butadiene, pentachlorobenzene, hexachlorobenzene, hexachlorocyclohexane—HCH—isomers, heptachlor) and six polybrominated diphenyl ethers (PBDEs; BDE-28, 47, 99, 100, 153, 154)—in fish samples. In the method, a modified QuEChERS (quick, easy, cheap, effective, rugged and safe) sample preparation using pH-tuned dispersive liquid–liquid microextraction (DLLME) and H2SO4 digestion fish extract clean-up is followed by gas chromatography–triple quadrupole tandem mass spectrometry (GC–QqQ-MS/MS) analysis. The method was validated in terms of linearity, limits of the method, recovery, accuracy, analysis of standard reference material (NIST SRM 1946), and estimation of combined uncertainty of the measurement (top-down approach). For validation, chub composite samples were used, and subsequently, the method was successfully applied to analysis of real samples of eight fish species. Finally, the method passed the analytical Eco-Scale evaluation as “an acceptable green analysis method”, and showed its advantages (simplicity, rapidity, low cost, high extract clean-up efficiency, good sensitivity) when compared to other reported QuEChERS based methods.

Simultaneous Detection of Eight Prohibited Flavor Compounds in Foodstuffs Using Gas Chromatography–Tandem Mass Spectrometry

A multiflavor detection method, using gas chromatography-triple quadrupole tandem mass spectrometry (GC-MS/MS), has been developed for the simultaneous identification and quantification of eight prohibited flavor compounds in daily foods. Under the optimized extraction conditions, samples were purified directly through membrane filtration. Variables affecting the GC-MS/MS were optimized to obtain better separation. The excellent selectivity and sensitivity achieved in multiple reactions monitoring mode allowed satisfactory confirmation and quantitation. In this study, the linear ranges of the target compounds were 0.05 to 500 ng/L with good correlation coefficients ( R2 > 0.999). The limits of detection of target compounds ranged from 0.005 to 0.2 μg/kg. The average recoveries were in the range of 80.2 to 110.6% (beef jerky), 82.3 to 94.1% (cod liver oil), and 83.6 to 104.1% (candy).

Simultaneous quantification of fifty-one odor-causing compounds in drinking water using gas chromatography-triple quadrupole tandem mass spectrometry

A wide range of compounds with various structural features can cause taste and odor (T&O) problems in drinking water. It would be desirable to determine all of these compounds using a simple analytical method. In this paper, a sensitive method combining liquid–liquid extraction (LLE) with gas chromatography-triple quadrupole tandem mass spectrometry (GC–MS/MS) was established to simultaneously analyze 51 odor-causing compounds in drinking water, including organic sulfides, aldehydes, benzenes, phenols, ethers, esters, ketones, nitrogenous heterocyclic compounds, 2-methylisoborneol and geosmin. Three deuterated analogs of target analytes, dimethyl disulfide-d6, benzaldehyde-d6 and o-cresol-3,4,5,6-d4, were used to correct the variations in recovery, and five isotope-labeled internal standards (4-chlorotoluene-d4, 1, 4-dichlorobenzene-d4, naphthalene-d8, acenaphthene-d10, phenanthrene-d10 respectively) were used prior to analysis to correct the variations arising from instrument fluctuations and injection errors. The calibration curves of the target compounds showed good linearity (R2 > 0.99, level = 7), and method detection limits (MDLs) below 1/10 of the odor threshold concentrations were achieved for most of the odorants (0.10–20.55 ng/L). The average recoveries of most of the analytes in tap water samples were between 70% and 120%, and the method was reproducible (RSD < 20%, n = 7). Additionally, concentrations of odor-causing compounds in water samples collected from three drinking water treatment plants (DWTPs) were analyzed by this method. According to the results, dimethyl trisulfide, dimethyl disulfide and indole were considered to be the key odorants responsible for the swampy/septic odor. 2-Methylisoborneol and geosmin were detected as the main odor-causing compounds for musty/earthy odor in DWTP B.

Rapid Sample Preparation Method with High Lipid Removal Efficiency for Determination of Sulphuric Acid Stable Organic Compounds in Fish Samples

A rapid and low-cost sample preparation method modifying the so-called QuEChERS (quick, easy, cheap, effective, rugged and safe) method was developed for the determination of H2SO4 stable organic compounds in fish samples. The method involves acetonitrile salting-out extraction and a novel clean-up procedure combining the pH-tuned dispersive liquid–liquid microextraction (DLLME) with conc. H2SO4 digestion. The H2SO4 treatment is carried out by a simple operation in contrast to laborious and time-consuming procedures reported in the literature. The method was developed, optimised and validated using selected polybrominated diphenyl ethers (PBDEs) as representatives of H2SO4 stable compounds. For instrumental analysis of sample extracts, thermal desorption–gas chromatography–triple quadrupole tandem mass spectrometry (TD–GC–QqQ-MS/MS) was used. The proposed sample preparation method provides better co-extractives removal efficiency as compared to the original QuEChERS method and, unlike the QuEChERS dispersive solid-phase extraction (dSPE), allows complete removal of fatty acids. The sample preparation is low-cost due to the employment of small amounts of low-cost chemicals (no need of expensive sorbents), and it does not require special instrumentation. The whole analytical method showed satisfactory performance (linearity, recovery, repeatability, accuracy, limits of the method), and its applicability was confirmed by determination of PBDEs in samples of four fish species with variable lipid content in the range of 0.7–19%. The obtained recoveries for six PBDEs in the NIST standard reference material SRM 1946 were in the range of 81–95%, and relative standard deviations were in the range of 3–13%.

Development of a method for the determination of SCCPs (short-chain chlorinated paraffins) in bivalve mollusk using Soxtec device followed by gas chromatography-triple quadrupole tandem mass spectrometry

BackgroundOrganochlorinated compounds are major environmental concern due to their persistence, long-range transportability and bio-accumulation. Chlorinated paraffin (CP) mixtures, especially short-chain CPs (SCCPs), are found in environmental samples at very high levels. However, information about their levels is still insufficient, mainly in marine biota.MethodsThis study aimed to optimize and validate a method for the determination of SCCPs (short-chain chlorinated paraffins) in bivalve mollusk using a Soxtec extractor and Gas Chromatography coupled with Mass Spectrometry in tandem GC-QqQ-MS/MS (EI). A Plackett-Burman (2^7*3/16) type III resolution factorial design was used to optimize the extraction and purification procedures, sample amount, extractant volume, boiling and rinsing times as extraction variables and alumina, acid silica gel amounts and elution volume as purification variables.ResultsThe most influent factors were sample amount, rinsing time, extractant volume and acid silica gel amount. Further experiments were performed in order to attain the optimal values of these factors (4 g sample amount, 50 mL n-hexane-dichloromethane as extractant volume, 2 and 1.5 h boiling and rinsing times, 8 g alumina, 4 g acid silica gel (15%) and 50 mL n-hexane-dichloromethane as elution solvent). Validation of the optimized method presented recoveries higher than 90% with RSD below 10%, showing good accuracy and precision. The whole method limits of detection and quantification were 46.13 mg Kg- 1 and 153.75 mg Kg- 1, respectively. This method was successfully applied to the analysis of wild mussel samples coming from two Galician Rías. The found levels were very low compared to other marine systems, below parts per million.ConclusionsThe main advantages of the optimized method lie in the rapidity and the low amount of sorbents and volume of solvent used, as well as the selectivity and sensitivity of triple quadrupole MS/MS.