Low-pressure Gas Chromatography Research Articles

Monitoring of 260 pesticides in extra virgin olive oil and risk assessment for consumers within the framework of the European multiannual control program

The aim of the present research was to develop and validate a robust analytical method for the monitoring of 260 pesticide residues in Extra Virgin Olive Oil (EVOO) expanding the 185 molecules requested by the multiannual control program. The analytical procedure included an ultrasound-assisted liquid-liquid microextraction followed by low-pressure gas chromatography (LP-GC) and ultra-high-performance liquid chromatography (UHPLC), both coupled to triple quadrupole mass spectrometry. Matrix-matched calibration curves showed good linearity with coefficients of determination greater than 0.999. Accuracy values ranged from 65.5 % to 122.3 % and from 61.1 % to 133.3 % for LP-GC and UHPLC, respectively. The recoveries ranged from 14.0 % to 177.9 %.Fifty commercial EVOO, from Italian and EU production, were analyzed to assess pesticide contamination during the 2021–2023 harvesting seasons. The research focused on evaluating consumer risk by assessing both chronic and acute dietary exposure, using the Pesticide Residue Intake Model developed by the EFSA.

A dilute-and-inject low-pressure gas chromatography-tandem mass spectrometry method for phthalate determination in extra virgin olive oil.

The goal of this study was to develop a method for the determination of nine phthalic acid esters in extra virgin olive oils using low-pressure gas chromatography-triple-quadrupole mass spectrometry. Sample preparation was simple, environmental friendly, and rapid inasmuch that it involved only dilution(<1mL of hexane). The low-pressure gas chromatography analyses were performed by using a 5 m wide-bore column. The limit of quantification for the phthalates ranged from 0.06 to 1.14mg kg-1 . Both intra- and interday precisions were measured, with coefficient of variation values ranging from 0.2% to 11.7%. The trueness of the method was measured by evaluating accuracy at the initial stage of the work and after 2 months, with values ranging between -8.7% and 12.1%. Moreover, blind accuracy was comprised between -11.6% and 14.2%. The method involves the use of simplified instrumentation and reduced analysis times (nearly two times faster) compared to a previously published comprehensive two-dimensional gas chromatography-triple-quadrupole mass spectrometry method, leading to a reduction of energy and helium consumption. The approaches were compared in analytical terms and for the environmental impact. In total, 23 olive oil samples were analyzed, with at least one phthalate detected in all but one sample.

Comprehensive two-dimensional gas chromatography under low-pressure conditions

The analysis of thermally labile and high-boiling point compounds by gas chromatography (GC) can be a challenge. One technique to overcome these challenges is low-pressure GC, which uses the vacuum produced from the mass spectrometer and wide-bore columns to elute compounds at significantly lower temperatures. While GC-MS is a powerful technique, comprehensive two-dimensional gas chromatography (GC × GC), allows for resolution of compounds that would typically coelute using GC. In this study, a pesticide standard mixture (8270 MegaMix Standard) was analyzed using a conventional GC × GC-TOFMS configuration (0.25 mm inner diameter (i.d.) to a 0.18 mm i.d. column) and low-pressure GC × GC-TOFMS configuration (0.53 mm i.d. to a 0.53 mm i.d. column). Elution temperatures, sensitivity, and peak capacity were investigated for both configurations. Compounds eluted an average of 30 °C less on the low-pressure GC × GC-TOFMS configuration compared to the conventional GC × GC-TOFMS configuration. Moreover, the compounds were separated in ∼13 min on the low-pressure GC × GC-TOFMS as opposed to 33 min for conventional GC × GC-TOFMS. However, due to the wide-bore columns and faster runtimes the low-pressure GC × GC-TOFMS had a lower, β corrected 2D peak capacity, nc,β,2D, of 1260 while the conventional GC × GC-TOFMS was 3588. Interestingly, both configurations yielded a similar peak capacity production of 93 peaks/min and 107 peaks/min for low-pressure and conventional GC × GC-TOFMS, respectively. A “real world” sample of diesel fuel was tested on the low-pressure and conventional GC × GC-TOFMS configurations and similar results were obtained compared to the pesticide standard mix except the peak capacity production of the low-pressure GC × GC-TOFMS configuration was higher than that of the conventional GC × GC-TOFMS method.

Fast pesticide analysis using low-pressure gas chromatography paired with a triple quadrupole mass spectrometer equipped with short collision cell technology.

RationaleA proof of concept showing GC–MS/MS analysis time for pesticides can be dramatically reduced while maintaining a similar separation efficiency by combining a low‐pressure gas chromatography (LPGC) column with the enhanced selected reaction monitoring (SRM) switching speed of the short collision cell of a JEOL JMS‐TQ4000GC.MethodsTriple‐quadrupole tandem mass spectrometry (standard EI + at 70 eV) was used to measure pesticides eluting from a low‐pressure gas chromatograph capillary column. Three transitions for each of 244 pesticide compounds were measured within an 11‐min analysis time, and the data were checked to confirm the method's reproducibility and ability to distinguish all three transitions for each pesticide.ResultsAll three transitions for all 244 pesticides were detected in the standard mixture at 1X concentration within the 11‐min analysis time. Relative standard deviation (RSD) of peak areas was less than 15% for 242 pesticides, and I/Q RSDs were less than 10% for 242 compounds. Retention time RSD over 15 replicates was less than 0.1%.ConclusionsResults show that analysis time can be markedly decreased using an LPGC column, and that the ability of the short collision cell to distinguish a large number of coeluting peaks makes the two technologies a natural pairing. The effective measurement of pesticides within a short time could benefit any scientists doing pesticide analysis work.

Validation of the QuEChERSER mega-method for the analysis of pesticides, veterinary drugs, and environmental contaminants in tilapia (Oreochromis Niloticus)

ABSTRACT Diverse food safety programmes around the world are designed to help ensure production of safe food. To meet this need, the development and implementation of more efficient and effective analytical methods to monitor residues (pesticides and veterinary drugs) and contaminants in food is important. In this study, we report the validation results for a simple high-throughput mega-method for residual analysis of 213 pesticides and veterinary drugs, including 15 metabolites, plus 12 environmental contaminants (polychlorinated biphenyls) in tilapia muscle for implementation in routine laboratory analyses. The generic sample preparation method and analytical approach are known as QuEChERSER (more than QuEChERS). A small portion of the initial extract (204 µL) is taken for analysis by ultrahigh-performance liquid chromatography (UHPLC) tandem mass spectrometry (MS/MS) covering 145 analytes, and the remaining extract undergoes a salting out step followed by an automated robotic instrument top sample preparation (ITSP) cleanup, also known as micro-solid-phase extraction (µSPE), plus fast low-pressure gas chromatography LPGC-MS/MS for 134 analytes (66 pesticides are targeted in both UHPLC-MS/MS and LPGC-MS/MS). The mega-method was validated in spiked tilapia samples at 5, 10, 15, and 20 ng/g with 10 replicates per level over two days (n = 80 overall), and 70–140% recoveries with RSDs ≤20% were achieved for 92% of the analytes in LC and 82% in GC. No significant matrix effects were observed for the analytes in LPGC-MS/MS, and only 5% of the analytes exceeded ±20% matrix effect in UHPLC-MS/MS. Analysis of standard reference materials (NIST SRMs 1946 and 1947) for contaminants in freeze-dried fish showed acceptable results, further demonstrating that the QuEChERSER mega-method can be implemented to expand analytical scope and increase laboratory efficiency compared to the QuEChERS method.

Analysis of the California list of pesticides, mycotoxins, and cannabinoids in chocolate using liquid chromatography and low-pressure gas chromatography-based platforms.

Cannabis legalization has led to the development of a variety of cannabis‐infused products with edibles being one of the most popular. The state of California has implemented comprehensive cannabis testing regulations requiring the analysis of cannabinoids (potency) and contaminants, such as pesticides and mycotoxins, in any type of cannabis good. In this work, we propose an analytical workflow for the quantification of the California list of pesticides and mycotoxins, as well as six cannabinoids, in chocolate, using 3 mL of solvent for the extraction. For the analysis of pesticides and mycotoxins, clean‐up steps employing a C18 solid‐phase extraction cartridge and dispersive solid‐phase extraction sorbents were implemented. Gas chromatography amenable pesticides were analyzed using low‐pressure gas chromatography coupled to tandem mass spectrometry which allowed for a total method run of 12 min. Both liquid chromatography and gas chromatography instrumental methods had the same analysis time, ensuring satisfactory sample throughput. For the determination of cannabinoids, a dilution of the original organic extract collected for pesticides and mycotoxins analysis (and prior to any clean‐up step) was used. Excellent results in terms of analytical figures of merit were obtained for all target analytes.

The Role of Chromatography in the Food Industry

The widespread usage of gas chromatography for food analysis makes it a value for scientific research. The typical chemical and food analysis tasks performed by Quall Expand use mostly quantitative or qualitative analysis of food constituents, poisons, pesticides, and waste chemicals. As well as the changes in food taste and packaging, and odour composition, and work with various extraction procedures such as using water and steam distillation, solvents. This review provides a general introduction to gas chromatography research and mentions the main uses of gas chromatography in food science in addition to high-performance liquid chromatography (HPLC). Trends from past and forecasted implementation practices are noted, evaluated, and possible trends in the present and possible future behavior of food industries. They predict that in food applications, which do not include the already gas chromatography, the fastest-developing research methods in the next decade would be used known as gas chromatography. The main three methods for quick gas chromatography are low-pressure gas chromatography or TOFOT gas chromatography/time-of-MS, which is only briefly defined, and the features of a gas chromatography are evaluated.

Validation of a high-throughput method for analysis of pesticide residues in hemp and hemp products

Hemp has been an agricultural commodity for millennia, and it has been undergoing a resurgence in interest and production due to its high content of cannabinoids, protein, fiber and other ingredients. For legal possession and use throughout the USA, hemp and hemp products must have delta-9-tetrahydrocannabinol (THC) concentration < 0.3%. As with most crops, pesticides may be applied when farming hemp, which need to be monitored in food, feed, and medicinal products. The aim of this work was to evaluate and validate the recently developed “quick, easy, cheap, effective, rugged, safe, efficient, and robust” (QuEChERSER) sample preparation mega-method to determine pesticide residues in hemp plants, flowers, powders, oils, and pellets. High-throughput analysis of final extracts for 106 targeted pesticides and metabolites from North American monitoring lists entailed: 1) ultrahigh-performance liquid chromatography - tandem mass spectrometry (UHPLC-MS/MS) with column back-flushing, and 2) instrument-top sample preparation + low-pressure gas chromatography (ITSP+LPGC-MS/MS). In QuEChERSER, 2 g sample is extracted with 10 mL 4/1 (v/v) acetonitrile/water by mechanical shaking for 10 min, followed by 3 min centrifugation. For LC, 0.2 mL of extract is taken and solvent exchanged into initial mobile phase followed by 5 min ultra-centrifugation prior to the 10 min analysis. For GC-amenable pesticides, the remaining initial extract is partitioned with 4/1 (w/w) anh. MgSO4/NaCl, and 1 mL is taken for automated ITSP cleanup in parallel with 10 min LPGC analysis. In the former case, the UHPLC column is back-flushed with 1/1 (v/v) methanol/acetonitrile for 3 min between each injection to keep the system clean and avoid ghost peaks. Multi-level, multi-day validation results achieved 70–120% recoveries with RSDs < 20% for more than 80% of the analytes in hemp protein powder, oil, pellets, and fresh plant (dried hemp plant and flower were too complex). Limits of quantification (LOQs) were < 10 ng/g were achieved for nearly all pesticides, yielding 2.8% false negatives among >13,000 analyte results in the spiked samples. The QuEChERSER method was demonstrated to meet the challenge for several complex hemp matrices.

Less than one minute low-pressure gas chromatography - mass spectrometry

Conventional gas chromatography - mass spectrometry (GC-MS) takes 20–40 min per sample, which is undesirably slow in any application if speed can be increased while still meeting analytical needs. In this study, we achieved reasonably good separations with full analysis cycle times of less than 1 min by combining for the first time low-pressure (LP) GC-MS with low thermal mass (LTM) resistive-heating for rapid temperature ramping and cooling of the capillary column. The analytical column is threaded into the LTM thin-walled metal tubing in an instrumental device known as “LTM Fast GC” that is mounted at the top of the gas chromatograph in a detector port. The column inlet and outlet are connected to the GC injector and MS transfer line as usual. For LPGC-MS, a 40 cm, 0.1 mm. i.d. uncoated flow restrictor capillary connected at the injector is coupled with a 2.6 m, 0.25 mm i.d., 0.25 µm film thickness analytical column leading to the MS. Thus, the inlet operates at normal GC pressures, but the analytical column is under vacuum, which increases the optimal helium carrier gas flow velocity thereby increasing speed of full range separations while maintaining acceptable quality of chromatography. This column configuration in LTM-LPGC-MS trades a 64-fold gain in speed of analysis vs. standard GC-MS for a 4-fold loss in chromatographic peak capacity, thereby converting analysis time from minutes into seconds in common applications. For example, jet fuel containing fatty acid methyl esters (akin to biofuel) was separated in 25 s with <1 min full analysis cycle time. An EPA Method 8270 mixture of 76 analytes was also analyzed in <1 min full cycle time by LTM-LPGC-MS. Other examples include very fast analysis of heroin in a street drug powder and elucidation of a new organic synthetic compound. In this report, we describe and discuss the several advantageous and practical features of LTM-LPGC-MS, as well as its trade-offs.

Applications of monolithic columns in gas chromatography and supercritical fluid chromatography.

Porous monoliths are well-known stationary phases in high-performance liquid chromatography and capillary electrochromatography. Contrastingly, their use in other types of separation methods such as gas or supercritical fluid chromatography is limited and scarce. In particular, very few studies address the use of monolithic columns in supercritical fluid chromatography. These are limited to silica-based monoliths and will be covered in this review together with an underlying reason for this trend. The application of monoliths in gas chromatography has received much more attention and is well documented in two reviews by Svec and Kurganov published in 2008 and 2013, respectively. The most recent studies, covered in this review, build on the previous findings and on further understanding of the influence of preparation conditions on porous properties and chromatographic performance of poly(styrene-co-divinylbenzene), polymethacrylate, and silica-based monolithic columns while expanding to polymer-based monoliths with incorporated metal organic frameworks and to vinylized hybrid silica monoliths. In addition, the potential application of porous layer open tubular monolithic columns in low-pressure gas chromatography will be addressed.

Low-pressure gas chromatography with chemical ionization mass spectrometry for quantification of multifunctional organic compounds in the atmosphere

Abstract. Oxygenated volatile organic compounds (OVOCs) are formed during the oxidation of gas-phase hydrocarbons in the atmosphere. However, analytical challenges have hampered ambient measurements for many of these species, leaving unanswered questions regarding their atmospheric fate. We present the development of an in situ gas chromatography (GC) technique that, when combined with the sensitive and specific detection of chemical ionization mass spectrometry (CIMS), is capable of the isomer-resolved detection of a wide range of OVOCs. The instrument addresses many of the issues typically associated with chromatographic separation of such compounds (e.g., analyte degradation). The performance of the instrumentation is assessed through data obtained in the laboratory and during two field studies. We show that this instrument is able to successfully measure otherwise difficult-to-quantify compounds (e.g., organic hydroperoxides and organic nitrates) and observe the diurnal variations in a number of their isomers.

Static Headspace Analysis Using Low-Pressure Gas Chromatography and Mass Spectrometry, Application to Determining Multiple Partition Coefficients: A Practical Tool for Understanding Red Wine Fruity Volatile Perception and the Sensory Impact of Higher Alcohols.

To evaluate the partition coefficients of volatiles between the liquid and gas phases, an analytical method was developed and optimized using static headspace analysis and low-pressure injection gas chromatography coupled to mass spectrometry (SHS-LP-GC/MS). Two different types of analytical columns were coupled for low-pressure chromatography injection: a narrow restriction microbore column on the inlet side and a mega-bore column on the mass spectrometer side. Coupling these two columns and static headspace analysis to gas chromatography and mass spectrometry resulted in a simple, fast, sensitive, and accurate approach. Several points have been optimized: time to reach the thermodynamic equilibrium in the gas phase, syringe filling rate, gas injection rate, and volume ratio between the gas and liquid phases. This new method was used to determine partition coefficients between the liquid and gas phases and study multicomponent mixtures for which particular perceptive interactions had previously been highlighted. The partition coefficients of 9 esters and 5 higher alcohols were determined in dilute alcohol solution (12% v/v) and dearomatized red wine. These partition coefficients revealed modifications in ester headspace release in the presence of higher alcohols for the first time in this type of matrix. The correlation of these results with sensory data highlighted the role of physicochemical, presensory effects on sensory modifications for the first time, suggesting that this type of interaction may partly modulate qualitative and quantitative fruity perception.

High-throughput analytical method for 265 pesticides and environmental contaminants in meats and poultry by fast low pressure gas chromatography and ultrahigh-performance liquid chromatography tandem mass spectrometry

A high throughput method for simultaneous determination of 200 pesticides and 65 environmental contaminants: polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and other flame retardants, was developed and validated in cattle, swine and poultry muscle tissues. The method was based on sample preparation with QuEChERS extraction followed by an automated robotic sample cleanup with solid phase extraction (SPE) mini-columns using Instrument Top Sample Preparation (ITSP). The automated robotic ITSP was integrated with instrumental analysis (low pressure (LP)GC–MS/MS) to conduct sample cleanup and analysis in parallel. Another aliquot of the initial QuEChERS extract was subjected to UHPLC-MS/MS analysis, and 53 overlapping pesticides were analyzed by both LPGC- and UHPLC-MS/MS (10 min each). Fit-for-purpose LOQs<5 ng/g were achieved for ≥90% of the analytes. The method was validated in cattle, swine and chicken muscles at three spiking levels at and below the US regulatory levels of concern, and satisfactory recoveries (70–120%) and RSDs ≤ 20% were demonstrated for 219 analytes. Matrix effects were within ±20% for 78–97% of LC- and GC-amenable analytes. The validated method was successfully applied for the analysis of real-world incurred meat and poultry samples, further demonstrating its applicability to real-world samples, and potential for implementation in routine monitoring of contaminants.

Analysis of triglycerides in butter, plant oils, and adulterated butter with LPGC-MS

This work is focused on the detection of butter adulteration by sunflower and rapeseed oils using low pressure gas chromatography mass spectrometry (LPGC-MS). The method is based on simple dissolution of triglycerides from butter samples in chloroform and their direct analysis with LPGC-MS. The method allows the detection of characteristic triglycerides as butter adulteration markers and their quantification in different samples, with the possibility to quantify plant oil addition to butter at 0.45% level (using m/z = 600.4 for rapeseed oil) and 0.15% for sunflower oil (using m/z = 598.4). Ten different commercial butters were tested for the presence of sunflower and rapeseed oil. Interestingly, the addition of rapeseed oil up to 1.2% was recorded in one butter brand.

Evaluation of a new carbon/zirconia‐based sorbent for the cleanup of food extracts in multiclass analysis of pesticides and environmental contaminants

A novel carbon/zirconia-based material, SupelTM QuE Verde, was evaluated in a filter-vial dispersive solid-phase extraction cleanup of pork, salmon, kale, and avocado extracts for the residual analysis of 65 pesticides and 52 environmental contaminants (flame retardants, polychlorinated biphenyls, polybrominated diphenyl ethers, and polycyclic aromatic hydrocarbons) using low-pressure gas chromatography with tandem mass spectrometry. An amount of 180 mg sorbent per 0.6 mL extract in filter-vial dispersive solid-phase extraction cleanup was found the optimum in terms of achieving satisfactory removal of co-extractives and recoveries of analytes, especially for structurally planar compounds. For analytes partially retained by Verde, normalization to an internal standard resulted in 62-107% recoveries. Addition of Verde to primary secondary amine and C18 in cleanup resulted in 38% more removal of gas-chromatography-amenable co-extractives in avocado, 30% in kale, 39% in salmon, and 50% in pork. The removal efficiency of co-extracted chlorophyll was 93% for kale and 64% for avocado based on ultraviolet-visible absorbance. The developed method was validated at three spiking levels (10, 25, and 100 ng/g), and 70-120% recoveries with ≤20% relative standard deviation were achieved for 96 (83%) out of 117 analytes in pork, 79 (69%) in salmon, 71 (62%) in kale, and 75 (65%) in avocado.

Automated Mini-Column Solid-Phase Extraction Cleanup for High-Throughput Analysis of Chemical Contaminants in Foods by Low-Pressure Gas Chromatography-Tandem Mass Spectrometry.

This study demonstrated the application of an automated high-throughput mini-cartridge solid-phase extraction (mini-SPE) cleanup for the rapid low-pressure gas chromatography—tandem mass spectrometry (LPGC-MS/MS) analysis of pesticides and environmental contaminants in QuEChERS extracts of foods. Cleanup efficiencies and breakthrough volumes using different mini-SPE sorbents were compared using avocado, salmon, pork loin, and kale as representative matrices. Optimum extract load volume was 300 µL for the 45 mg mini-cartridges containing 20/12/12/1 (w/w/w/w) anh. MgSO4/PSA (primary secondary amine)/C18/CarbonX sorbents used in the final method. In method validation to demonstrate high-throughput capabilities and performance results, 230 spiked extracts of 10 different foods (apple, kiwi, carrot, kale, orange, black olive, wheat grain, dried basil, pork, and salmon) underwent automated mini-SPE cleanup and analysis over the course of 5 days. In all, 325 analyses for 54 pesticides and 43 environmental contaminants (3 analyzed together) were conducted using the 10 min LPGC-MS/MS method without changing the liner or retuning the instrument. Merely, 1 mg equivalent sample injected achieved <5 ng g−1 limits of quantification. With the use of internal standards, method validation results showed that 91 of the 94 analytes including pairs achieved satisfactory results (70–120 % recovery and RSD ≤ 25 %) in the 10 tested food matrices (n = 160). Matrix effects were typically less than ±20 %, mainly due to the use of analyte protectants, and minimal human review of software data processing was needed due to summation function integration of analyte peaks. This study demonstrated that the automated mini-SPE + LPGC-MS/MS method yielded accurate results in rugged, high-throughput operations with minimal labor and data review.Electronic supplementary materialThe online version of this article (doi:10.1007/s10337-016-3116-y) contains supplementary material, which is available to authorized users.

Evaluation of a recent product to remove lipids and other matrix co-extractives in the analysis of pesticide residues and environmental contaminants in foods

This study demonstrates the application of a novel lipid removal product to the residue analysis of 65 pesticides and 52 environmental contaminants in kale, pork, salmon, and avocado by fast, low pressure gas chromatography – tandem mass spectrometry (LPGC–MS/MS). Sample preparation involves QuEChERS extraction followed by use of EMR-Lipid (“enhanced matrix removal of lipids”) and an additional salting out step for cleanup. The optimal amount of EMR-Lipid was determined to be 500mg for 2.5mL extracts for most of the analytes. The co-extractive removal efficiency by the EMR-Lipid cleanup step was 83–98% for fatty samples and 79% for kale, including 76% removal of chlorophyll. Matrix effects were typically less than ±20%, in part because analyte protectants were used in the LPGC–MS/MS analysis. The recoveries of polycyclic aromatic hydrocarbons and diverse pesticides were mostly 70–120%, whereas recoveries of nonpolar polybrominated diphenyl ethers and polychlorinated biphenyls were mostly lower than 70% through the cleanup procedure. With the use of internal standards, method validation results showed that 76–85 of the 117 analytes achieved satisfactory results (recoveries of 70–120% and RSD≤20%) in pork, avocado, and kale, while 53 analytes had satisfactory results in salmon. Detection limits were 5–10ng/g for all but a few analytes. EMR-Lipid is a new sample preparation tool that serves as another useful option for cleanup in multiresidue analysis, particularly of fatty foods.

Method validation for 243 pesticides and environmental contaminants in meats and poultry by tandem mass spectrometry coupled to low-pressure gas chromatography and ultrahigh-performance liquid chromatography

An easy and reliable high-throughput analysis method was developed and validated for 192 diverse pesticides and 51 environmental contaminants (13 PCB congeners, 14 PAHs, 7 PBDE congeners, and 17 novel flame retardants) in cattle, swine, and poultry muscle. Sample preparation was based on the “quick, easy, cheap, effective, rugged and safe” (QuEChERS) approach using filter-vial dispersive solid-phase extraction (d-SPE) cleanup. Split final extracts were analyzed in parallel by low-pressure (vacuum outlet) GC-MS/MS and UHPLC-MS/MS (10 min each), providing an additional degree of confirmation for 55 overlapping LC- and GC-amenable pesticides. Analyte protectants were utilized to improve sensitivity and decrease matrix effects in GC analysis, and only filtration of initial extracts was enough to avoid ion suppression in UHPLC-MS/MS. The method was validated at three spiking levels (10, 25, and 100 ng/g) at or below established tolerance levels in the sample types. Satisfactory recoveries (70–120%) and RSDs ≤ 20% were achieved for 200 analytes. The validated method was successfully applied to the analysis of real-world incurred meat samples, further demonstrating the utility of the method for implementation in regulatory and commercial laboratories.

Rapid and sensitive multiresidue analysis of pesticides in tobacco using low pressure and traditional gas chromatography tandem mass spectrometry

Public exposure to pesticide residues through the main/side-stream smoke of tobacco (Nicotiana tabacum L.) is an international concern. This article reports optimization and validation of large-scale multiresidue analysis methods involving low pressure and traditional gas chromatography tandem mass spectrometry in compliance with the guidance residue levels (GRLs) of Cooperative Centre for Scientific Research Relative to Tobacco (CORESTA). Analysis by low pressure GC–MS/MS offered three times rapid turn around time over the traditional GC–MS/MS with limits of quantifications (LOQs) less than 2μg/L for all the 259 test compounds and the recoveries in the range of 70–118% (±20%) at 10 and 20μg/kg levels of fortification.

Higher cytotoxicity and genotoxicity of burning incense than cigarette

Hazardous particulates and volatiles produced by incense burning accumulate in the indoor atmosphere, where they pose a health risk, entering the human body via the respiratory system. Yet, few studies have focused on the effects of the total particulate matter from incense burning on human health. Here, we evaluate the health risks associated with the total particulate matter generated from burning incense indoors for the first time. The total particulate matter and major chemical components of two types of incense smoke were characterized using an electrical low pressure impactor and gas chromatography coupled with mass spectrometry. Their genotoxicity and cytotoxicity were compared with mainstream tobacco smoke using in vitro assays. Our results show that both the particulate number and mass of incense smoke were dominated by ultrafine to fine particles. In addition, many aromatic, irritant, and toxic compounds were identified in the particulate fraction. In vitro assessments showed that the genotoxicity of the particulate matter from one particular incense sample was higher than the reference cigarette sample with the same dose. All particulate matter fractions from the incense investigated were found to possess greater cytotoxicity on Chinese hamster ovary cells than smoke from the reference cigarette. Collective assessment of these data will affect the evaluation of incense products and facilitate measures to reduce exposure to their smoke. Clearly, there needs to be greater awareness and management of the health risks associated with burning incense in indoor environments.