Multiclass screening of >200 pharmaceutical and other residues in aquatic foods by ultrahigh-performance liquid chromatography-quadrupole-Orbitrap mass spectrometry

Development and validation of rapid screening of 192 veterinary drug residues in aquatic products using HPLC-HRMS coupled with QuEChERS

The presence of veterinary drug residues in aquatic products represents a significant challenge to food safety. The current detection methods, limited in both scope and sensitivity, underscore the urgent need for more advanced techniques. This research introduces a swift and potent screening technique using high-performance liquid chromatography-high-resolution mass spectrometry (HPLC-HRMS) and a refined QuEChERS protocol, allowing simultaneous qualitative and semi-quantitative analysis of 192 residues. A comprehensive database, employing full scan mode and data-dependent secondary mass spectroscopy, enhances screening accuracy. The method involves efficient extraction using 90% acetonitrile, dehydration with Na2SO4, and acetic acid, followed by cleanup using dispersive solid-phase extract sorbent primary secondary amine. It is suitable for samples with varying fat content, offering detection limits ranging from 0.5 to 10 μg/kg, high recovery rates (60-120%), and low relative standard deviations (<20%). Practical application has validated its effectiveness for multi-residue screening, marking a significant advancement in food safety evaluation.

One step cleanup of 160 pesticides and veterinary drugs in aquatic products using melamine-based automatic pressure filtration purification method combined with HPLC-MS/MS

A 15-channel pressure filtration purification method was presented for high throughput sample preparation of aquatic products. A cost-effective device was constructed and melamine sponge was selected as the cleanup sorbent. Upon interfacing with HPLC-MS/MS, the analytical procedure demonstrated its suitability for quantifying 160 pesticides and veterinary drug residues in aquatic products such as fish, shrimp, and crab. The method achieved sample recoveries ranging from 61.3 to 124.9 %. The detection limits were established between 0.5 and 1.0 μg/kg, while the quantitation limits were confirmed to be within the range of 1.0-2.0 μg/kg. The method was applied to quantify the pesticide and veterinary drug residues in mostly consumed aquatic products from five coastal provinces in China. The results showed significant differences between different aquatic products in the concentrations of pesticide and veterinary drug residues, implying the necessity of supervision for the accurate determination of pesticides and veterinary drugs.

Novel filter-press single-step cleanup approach facilitated rapid screening and accurate quantification of 112 veterinary drugs in aquatic products

In this study, a novel filter-press cleanup column was developed as a single-step cleanup approach for the rapid screening and quantification of 112 veterinary drugs in fish samples. Fish muscle samples were extracted with acetonitrile and ethyl acetate, sequentially. After concentration and reconstitution, N-propylethylenediamine (PSA) sorbent, packed in filter-press column, allows rapid single-step cleanup operation, while UHPLC-Q-Orbitrap-HRMS provides high-precision mass information in multi-residue screening. Under optimum settings, the detection and quantification limits were validated at 0.5 and 2.0 μg·kg-1, for all analytes, respectively. The ranges of recoveries were from 35.3 to 138.4%. Most of these target analytes (82%) could be measured with recoveries between 60 and 130%, and intra-day RSDs ranging from 1.9 to 26.1%. This method was further applied to evaluate the residual of veterinary drugs in fish samples from four cities in China, and results demonstrated its practicability for multi-residue monitoring veterinary residues for food safety administration.

Multi-Residue Screening of Pesticides in Aquatic Products Using High-Performance Liquid Chromatography-Tandem High-Resolution Mass Spectrometry

Pesticide residues in aquatic products are of great concern due to the risk of environmental transmission and their extensive use in aquaculture. In our work, a quick screening approach was developed for the qualitative and semi-quantitative screening of 87 pesticide residues in aquatic products. The sample preparation was investigated, including extract solvent, extract methods, buffer salts, lipid removal, cleanup materials and filter membranes for aquatic products. Samples were extracted using a modified QuEChERS procedure, and two clean-up procedures were developed for UHPLC-Q/Orbitrap MS analysis based on the fat content of the aquatic products. The screening detection limits for all studied pesticides were distributed between 1 and 500 μg/kg in the three representative matrices. Seventy-one pesticides could be analyzed with a screening limit between 1 and 25 μg/kg in grass carp and crayfish, sixty-one pesticides could be screened for limits between 1 and 50 μg/kg in crab. The accuracy results showed that recoveries ranged from 50 to 120% for 60, 56 and 52 pesticides at medium-level for grass carp, crayfish and crab, respectively. At high spiking levels, 74, 65 and 59 pesticides were recovered within the range of 50-120% for the three matrices, respectively. The relative standard deviations of most compounds in different matrices were less than 20%. With this method, the local farmed aquatic products were tested for pesticide residues. In these samples, ethoxyquinoline, prometryn and phoxim were frequently detected. The majority of these confirmed compounds did not exceed 2.00 μg/kg. A grass carp with trichlorfon at 4.87 μg/kg and two carps with ethoxyquinoline at 200 µg/kg were detected, indicating the potential dietary risk.

Multiresidues Multiclass Analytical Methods for Determination of Antibiotics in Animal Origin Food: A Critical Analysis

Veterinary drugs are widely used to prevent and treat diseases. The European Union has forbidden the use of antibiotics as growth promoters since 2006. Its abusive use leads to the presence of antibiotic residues (AR) in foods of animal origin which is associated with antibiotic resistance. The monitoring of AR in food intended for human consumption is of utmost importance to assure Food Safety. A systematic bibliographic review was carried out on the analytical methodologies, published in 2013, for the determination of AR in foods of animal origin. The food processing effect in the AR detected in animal products is also addressed. However, there is a preference for multiresidues multiclass methods, i.e., methodologies that allow determining simultaneously different classes of antibiotics, which is still a challenge for researchers. The wide diversity of physico-chemical properties of these drugs is an obstacle to achieving excellent analytical performance for a vast number of molecules analyzed concurrently. New techniques in sample preparation continue to be developed in order to obtain a compromise between good recoveries and extracts without interferences (clean extracts). The most widely used analytical methodology for the determination of AR is liquid chromatography coupled with mass spectrometry. However, the current trend is focused on the use of powerful high-resolution MS detectors such as Time of Flight and Orbitrap with modern chromatographic systems. Cooking time and temperature control are the key processing conditions influencing the reduction of AR in foods.

Discrimination of Atlantic salmon origins using untargeted chemical fingerprinting

Mislabelling the geographic origin of same-species aquaculture products is difficult to identify. This study applied untargeted small-molecule fingerprinting to discriminating between Atlantic salmon originating from Chile and Norway. The acquired liquid chromatography-high-resolution mass spectrometry data from Chilean (n = 32) and Norwegian (n = 29) salmon were chemometrically processed. The partial least squares discriminant analysis (PLS-DA) models successfully discriminated between Chilean and Norwegian salmon at both positive and negative ionisation modes (R² > 0.96, Q² > 0.81). Univariate analyses facilitated the selection of approximately 100 candidate markers with high statistical confidence (> 95%). Of these, 37 confirmed markers of Chilean and Norwegian salmon were primarily associated with feed formulations, including lipid derivatives and feed additives. None of the markers were residues or contaminants of potential food safety concern.

Current perspective on veterinary drug and chemical residues in food of animal origin

The marked increase in the demand for animal protein of high quality necessitates protecting animals from infectious diseases. This requires increasing the use of veterinary therapeutics. The overuse and misuse of veterinary products can cause a risk to human health either as short-term or long-term health problems. However, the biggest problem is the emergence of resistant strains of bacteria or parasites. This is in addition to economic losses due to the discarding of polluted milk or condemnation of affected carcasses. This paper discusses three key points: possible sources of drug and chemical residues, human health problems, and the possible method of control and prevention of veterinary drug residues in animal products.

Comparison of four different multiclass, multiresidue sample preparation methods in the analysis of veterinary drugs in fish and other food matrices

In 2018, AOAC International issued Standard Method Performance Requirements (SPMR) 2018.010 - Screening and Identification Method for Regulated Veterinary Drug Residues in Food. In response, we compared 4 different multiresidue methods of sample preparation using the same analytical method entailing ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Tilapia was chosen for testing, and the analytes and monitoring levels were from SPMR 2018.010. The methods consist of efficient procedures with published validation results from the US Department of Agriculture (USDA), Food and Drug Administration (FDA), and Canadian Food Inspection Agency (CFIA), and an enhanced-matrix removal (EMR)-Lipid protocol from China. Each method was used to prepare 102 final extracts of tilapia spiked or not at different levels with the 78 targeted analytes plus metabolites. The same FDA/USDA rules of mass spectral identification were employed in all analyses to assess rates of false positives and negatives. Quantitative accuracy of the methods was also compared in terms of recoveries and reproducibility of spiked tilapia, incurred catfish, and spiked and certified reference material of bovine muscle. Each method yielded generally acceptable results for the targeted veterinary drugs, but the USDA "extract & inject" method was the fastest, simplest, and cheapest to achieve equally or more acceptable results for the widest scope of analytes for the tested food matrices.

Characteristics of veterinary antibiotics in intensive livestock farming watersheds with different liquid manure application programs using UHPLC-q-orbitrap HRMS combined with on-line SPE

Composted livestock manures, in both solid and liquid form, are used as fertilizers in cropland. However, excess solid and liquid manures in agricultural watersheds are considered as nonpoint pollution sources because of their high nutrient and heavy metal contents of, as well as their antibiotic contents, especially veterinary antibiotics (VAs). In this study, 21 VAs under nine classes (i.e., cephems, ionophores, lincosamides, penicillins, pleuromutilins, quinolones, streptogramins, sulfonamides, and tetracyclines) found in agricultural watersheds were simultaneously analyzed via UHPLC-q-orbitrap high-resolution mass spectrometry using an on-line solid-phase extraction system. The residues of VAs in the surface water of two intensive livestock rearing watersheds (Cheongmi and Gwangcheon streams) in Korea were successfully quantified, and the values were found to range from 1.84 ± 0.42 ng L^-1 to 835.6 ± 31.9 ng L^-1. Time lags of 2-3 months were observed between the periods of liquid manure application and the periods with the maximum concentrations of VAs. In both watersheds, samples from points close to areas with extensive application of liquid manure exhibited high concentrations of most of the 21 VAs. Between the watersheds, the one with heavier application of liquid manure showed higher concentrations of the target VAs. To the best of our knowledge, this study represents the first attempt at evaluating the correlation between liquid manure application and environmental occurrence of VAs in surface water. The findings reveal that liquid manure application plays an important role in introducing VAs into aquatic environments.

Simultaneous screening for chemically diverse micropollutants in public water bodies in Japan by high-performance liquid chromatography-Orbitrap mass spectrometry

An improved assessment of environmental risks to public water bodies requires screening a large number of micropollutants. This study reports the development of a novel target screening method based on solid-phase extraction (SPE), HPLC, and high-resolution Orbitrap MS for the analysis of micropollutants with diverse chemical properties. First, target compounds were screened for their detectability by Orbitrap MS. An optimized SPE cartridge and HPLC column maximized recovery and separated most target compounds. The sensitivity and repeatability of the method was validated by determining the detection limits and relative standard deviation (RSD). Eighty-four compounds with highly diverse properties were simultaneously detected with detection limits of 0.1-100 ng/L. Of these compounds, 52 were quantitated, with R2 ≥ 0.99 by linearity analysis and SPE recovery ratios of ≥50%. The remaining 32 compounds were qualitatively detected, with R2 < 0.99 or SPE recovery ratio of <50%. Satisfactory repeatability was obtained (RSD < 13.5%). This method was applied to the surveillance of the Arakawa River in Japan in 2019. Thirty-two compounds, including pesticides, surfactants, plasticizers, adhesives, and industrial solvents, were detected in the river. The measured concentrations of 13 compounds were compared with their predicted no effect concentrations (PNECs). Decanoic acid showed a higher concentration than the corresponding PNEC value, suggesting that its risk to the Arakawa water environment required further evaluation. The concentrations of dicyclohexylamine, 1,3-diphenylguanidine, and 2,4-dichlorophenoxyacetic acid were higher than their corresponding PNEC/10 values, demonstrating that these compounds were of higher priority than other compounds.

Technical Overview of Orbitrap High Resolution Mass Spectrometry and Its Application to the Detection of Small Molecules in Food (Update Since 2012)

Food safety and quality issues are becoming increasingly important and attract much attention, requiring the development of better analytical platforms. For example, high-resolution (especially Orbitrap) mass spectrometry simultaneously offers versatile functions such as targeted/non-targeted screening while providing qualitative and quantitative information on an almost unlimited number of analytes to facilitate routine analysis and even allows for official surveillance in the food field. This review covers the current state of Orbitrap mass spectrometry (OMS) usage in food analysis based on research reported in 2012-2019, particularly highlighting the technical aspects of OMS application and the achievement of OMS-based screening and quantitative analysis in the food field. The gained insights enhance our understanding of state-of-the-art high-resolution mass spectrometry and highlight the challenges and directions of future research.

Application of Nanostructured Carbon-Based Electrochemical (Bio)Sensors for Screening of Emerging Pharmaceutical Pollutants in Waters and Aquatic Species: A Review

Pharmaceuticals, as a contaminant of emergent concern, are being released uncontrollably into the environment potentially causing hazardous effects to aquatic ecosystems and consequently to human health. In the absence of well-established monitoring programs, one can only imagine the full extent of this problem and so there is an urgent need for the development of extremely sensitive, portable, and low-cost devices to perform analysis. Carbon-based nanomaterials are the most used nanostructures in (bio)sensors construction attributed to their facile and well-characterized production methods, commercial availability, reduced cost, high chemical stability, and low toxicity. However, most importantly, their relatively good conductivity enabling appropriate electron transfer rates-as well as their high surface area yielding attachment and extraordinary loading capacity for biomolecules-have been relevant and desirable features, justifying the key role that they have been playing, and will continue to play, in electrochemical (bio)sensor development. The present review outlines the contribution of carbon nanomaterials (carbon nanotubes, graphene, fullerene, carbon nanofibers, carbon black, carbon nanopowder, biochar nanoparticles, and graphite oxide), used alone or combined with other (nano)materials, to the field of environmental (bio)sensing, and more specifically, to pharmaceutical pollutants analysis in waters and aquatic species. The main trends of this field of research are also addressed.

Multi-Residue Screening of Pesticides in Aquaculture Waters through Ultra-High-Performance Liquid Chromatography-Q/Orbitrap Mass Spectrometry

Pesticide residues in foodstuffs can lead to several undesirable effects. A simple and high-throughput targeted screening method analyzing multi-residue pesticide in aquaculture water based on ultra-high-performance liquid chromatography-Q/Orbitrap mass spectrometry (UHPLC-Q/Orbi MS) was developed and validated. In this technique, the peaks of the compound using precursor ions were recorded by the full scan, which was used for rough quantitative analysis with single point matrix matched calibration. The qualitative identification was performed following the stringent confirmation criteria with fragment ions, retention time, and an isotopic pattern. Additionally, solid-phase extraction with an HLB (Hydrophilic/Lipophilic Balanced) column was selected to enrich and separate target pesticides from water. The screening detection limit of 33 compounds are less than 2 ng·L−1, while 26 compounds range from 2 ng·L−1 to 10 ng·L−1, 19 compounds are at the range of 10–200 ng·L−1, and the other two compounds are 200 ng·L−1 and 1000 ng·L−1. Most of the recovery results were found to be between 60~130%. Finally, the method was successfully applied to the analysis of pesticide residues in 30 water samples from aquaculture environment in Shanghai, indicating its applicability in pesticide screening for environmental monitoring.

Simultaneous Determination of Pesticides and Veterinary Pharmaceuticals in Environmental Water Samples by UHPLC–Quadrupole-Orbitrap HRMS Combined with On-Line Solid-Phase Extraction

Pesticides and veterinary pharmaceuticals are used for effective crop production and prevention of livestock diseases; these chemicals are released into the environment via various pathways. Although the chemicals are typically present in trace amounts post-release, they could disturb aquatic ecosystems and public health through resistance development toward drugs or diseases, e.g., reproductive disorders. Thus, the residues of pesticides and veterinary pharmaceuticals in the environment must be managed and monitored. To that end, we developed a simultaneous analysis method for 41 target chemicals in environmental water samples using ultra-high-performance liquid chromatography (UHPLC)–quadrupole-orbitrap high-resolution mass spectrometry (HRMS) coupled with an on-line solid-phase extraction system. Calibration curves for determining linearity were constructed for 10–750 ng∙L−1, and the coefficient of determination for each chemical exceeded 0.99. The method’s detection and quantitation limits were 0.32–1.72 ng∙L−1 and 1.02–5.47 ng∙L−1, respectively. The on-line solid-phase extraction system exhibited excellent method reproducibility and reduced experimental error. As the proposed method is applicable to the monitoring of pesticides and veterinary pharmaceuticals in surface water and groundwater samples acquired near agricultural areas, it allows for the management of chemicals released into the environment.

Suspect screening of plastic-related chemicals in northern pike (Esox lucius) from the St. Lawrence River, Canada

Environmental contaminant monitoring traditionally relies on targeted analysis, and very few tools are currently available to monitor "unexpected" or "unknown" compounds. In the present study, a non-targeted workflow (suspect screening) was developed to investigate plastic-related chemicals and other environmental contaminants in a top predator freshwater fish species, the northern pike, from the St. Lawrence River, Canada. Samples were extracted using sonication-assisted liquid extraction and analyzed by high performance liquid chromatography coupled with quadrupole time of flight mass spectrometry (HPLC-QTOF-MS). Ten bisphenol compounds were used to test the analytical performances of the method, and satisfactory results were obtained in terms of instrumental linearity (r² > 0.97), recoveries, (86.53-119.32%), inter-day precision and method detection limits. The non-targeted workflow data processing parameters were studied, and the peak height filters (peak filtering step) were found to influence significantly the capacity to detect and identify trace chemicals in pike muscle extracts. None of the ten bisphenol analogues were detected in pike extracts suggesting the absence of accumulation for these chemicals in pike muscle. However, the non-targeted workflow enabled the identification of diethyl phthalate (DEP) and perfluorooctanesulfonic acid (PFOS) in pike extracts. This approach thus can be also applied to various contaminants in other biological matrices and environmental samples.

Development of a liquid chromatography-quadrupole-time-of-flight-mass spectrometry based method for the targeted and suspect screening of contaminants in the pearl oyster Pinctada imbricata radiata

A rapid method based on solvent extraction followed by direct injection in liquid chromatography-quadrupole-time-of-flight-mass spectrometry (LC-Q-TOF-MS) was developed for the targeted and suspect screening of contaminants in the soft tissues of the pearl oyster Pinctada imbricata radiata. The quantification method was first validated for the targeted analysis of 21 contaminants including some pharmaceutically active compounds, with the relative recoveries ranging from 88 to 123%, and method detection limits generally below 1 ng g^-1 on the wet weight (ww) basis. This targeted analysis method was then applied to oyster samples collected around the Qatari coast between 2017/2018, and none of the 21 compounds were detected in these samples. The post-acquisition data treatment based on the accurate mass measurement in both full MS scan and All Ions MS/MS was further used for mining other contaminants in oyster extracts, as well as 21 targeted compounds spiked in oyster extracts (suspect screening). The 21 spiked compounds were identified successfully and the estimated limit of identification for the individual 21 compounds ranged from 0.5 to 117 ng g^-1 ww of oyster tissues. A phthalate, di(2-ethylhexyl) phthalate (DEHP) was identified to be present in oyster extracts from 2018 batches, at a concentration level significantly higher than that in procedure blanks. These results confirmed that high resolution MS data obtained using the targeted method can be exploited through suspect screening workflows to identify contaminants in the tissues of bioindicator mollusks. However, a number of false identifications could be obtained and future work will be on improving the success rate of the correct identifications using this workflow.

Detection, occurrence, and fate of emerging contaminants in agricultural environments (2019)

A review of 82 papers published in 2018 is presented. The topics ranged from detailed descriptions of analytical methods, to fate and occurrence studies, to ecological effects and sampling techniques for a wide variety of emerging contaminants likely to occur in agricultural environments. New methods and studies on veterinary pharmaceuticals, microplastics, and engineered nanomaterials in agricultural environments continue to expand our knowledge base on the occurrence and potential impacts of these compounds. This review is divided into the following sections: Introduction, Analytical Methods, Fate and Occurrence, Pharmaceutical Metabolites, Anthelmintics, Microplastics, and Engineered Nanomaterials. PRACTITIONER POINTS: New research describes innovative new techniques for emerging contaminant detection in agricultural settings. Newer classes of contaminants include human and veterinary pharmaceuticals. Research in microplastics and nanomaterials shows that these also occur in agricultural environments and will likely be topics of future work.

Extended liquid chromatography high resolution mass spectrometry screening method for veterinary drug, pesticide and human pharmaceutical residues in aquaculture fish

A liquid chromatography high resolution mass spectrometry (LC-HRMS) screening method was developed previously to analyze for veterinary drug residues commonly found in different types of aquaculture products. This method has been further evaluated for its feasibility to detect several other classes of compounds that might also be a concern as possible contaminants in farmed tilapia, salmon, eel and shrimp. Some chemicals could contaminate water sources used in aquaculture production through agricultural run-off. These compounds include several widely used triazine herbicides, organophosphate and carbamate pesticides, as well as various discarded human pharmaceuticals. Other possible contaminants investigated were selected disinfectants, some newer antibiotics, growth promoters, and various parasiticides. The sample preparation consisted of an acidic acetonitrile extraction followed by solid-phase extraction clean-up. Data were collected with a quadrupole-Orbitrap MS using both non-targeted and targeted acquisition. This rapid clean-up procedure and HRMS detection method described previously for veterinary drug residues also worked well for many other types of compounds. Most analytes had screening limit levels between 0.5-10 ng/g in the matrices examined using exact mass identification criteria. The strategy described in this paper for testing the performance of additional analytes will help expand the applicability of the HRMS procedure as aquaculture samples can now be analyzed for a wider range of contaminants.

Screening 89 Pesticides in Fishery Drugs by Ultrahigh Performance Liquid Chromatography Tandem Quadrupole-Orbitrap Mass Spectrometer

Multiclass screening of drugs with high resolution mass spectrometry is of great interest due to its high time-efficiency and excellent accuracy. A high-scale, fast screening method for pesticides in fishery drugs was established based on ultrahigh performance liquid chromatography tandem quadrupole-Orbitrap high-resolution mass spectrometer. The target compounds - were diluted in methanol and extracted by ultrasonic treatment, and the extracts were diluted with MeOH-water (1:1, v/v) and centrifuged to remove impurities. The chromatographic separation was performed on an Accucore aQ-MS column (100 mm × 2.1 mm, 2.6 μm) with gradient elution using 0.1% formic acid in water (containing 5 mmol/L ammonium formate) and 0.1% formic acid in methanol (containing 5 mmol/L ammonium formate) in Full Scan/dd-MS2 (TopN) scan mode. A screening database, including mass spectrometric and chromatographic information, was established for identification of compounds. The screening detection limits of methods ranged between 1–500 mg/kg, the recoveries of real samples spiked with the concentration of 10 mg/kg and 100 mg/kg standard mixture ranged from 70% to 110% for more than sixty compounds, and the relative standard deviations (RSDs) were less than 20%. The application of this method showed that target pesticides were screened out in 10 samples out of 21 practical samples, in which the banned pesticide chlorpyrifos were detected in 3 out of the 10 samples.

Expanding phytoremediation to the realms of known and unknown organic chemicals of concern

Recent advancements in analytical chemistry and data analyses via high-resolution mass spectrometry (HRMS) are evolving scientific understanding of the potential totality of organic chemical exposure and pollutant risk. This review addresses the importance of HRMS approaches, namely suspect screening and nontarget chemical analyses, to the realm of phytoremediation. These analytical approaches are not without caveats and constraints, but they provide an opportunity to understand in greater totality how plant-based technologies contribute, mitigate, and reduce organic chemical exposure across scales of experimental and system-level studies. These analytical tools can enlighten the complexity and efficacy of plant-contaminant system design and expand our understanding of biogenic and anthropogenic chemicals at work in phytoremediation systems. Advances in data analytics from biological sciences, such as metabolomics, are crucial to HRMS analysis. This review provides an overview of targeted, suspect screening, and nontarget HRMS approaches, summarizes the expanding knowledge of regulated and unregulated organic chemicals in the environment, addresses requisite HRMS instrumentation, analysis cost, uncertainty, and data processing techniques, and offers potential bridges of HRMS analyses to phytoremediation research and application.

Multiresidue Pesticides Analysis of Vegetables in Vietnam by Ultrahigh-Performance Liquid Chromatography in Combination with High-Resolution Mass Spectrometry (UPLC-Orbitrap MS)

An ultrahigh-performance liquid chromatography in combination with high-resolution mass spectrometry Thermo Q-Extractive Focus Orbitrap MS has been introduced for analysis of multiclass pesticides in vegetable samples collected in Hanoi, Vietnam. Multiclass pesticides were separated on the Thermo Hypersil Gold PFP column utilizing a gradient of the mobile phase consisting of 5 mM ammonium formate, 0.1% formic acid in deionized water, and methanol. The target analytes were detected in the full-scan mode on Thermo Scientific Q-Exactive Focus Orbitrap MS for quantitation at the optimum operating conditions. These conditions included, but not limit to, the resolution of 70000 at the full width at half maximum in both positive and negative mode, mass range from 80 to 1000 m/z, and optimized parameters for the heated electrospray ionization source. The identification of the analytes in real samples was based on retention times, mass to charge ratios, mass accuracies, and MS/MS spectra at the confirmation mode with the inclusion list of target analytes. The mass accuracies of target analytes were from -4.14 ppm (dinotefuran) to 1.42 ppm (cinosulfuron) in the neat solvent and from -3.91 ppm (spinosad D) to 1.29 ppm (cinosulfuron) in the matrix-matched solution. Target analytes in the vegetable-based matrix were extracted by the QuEChERS method. Some critical parameters of the analytical method such as linearity, repeatability, limit of detection, and limit of quantitation have been evaluated and implemented. Excellent LOD and LOQ of the developed method were achieved at the range of 0.04-0.85 and 0.13-2.9 μg·kg^-1, respectively. Intraday and interday repeatability of the analytical signal (peak area, n=6) of the developed method were below 3% and 10%, correspondingly. The matrix effect, extraction recovery, and overall recovery were fully investigated by spiking experiments. Experimental results demonstrated that the ionization suppression or enhancement was the main contribution on the overall recoveries of target analytes. Finally, the in-house validated method was applied to pesticides screening in vegetables samples in local villages in Hanoi, Vietnam. The concentrations of all target analytes were below limit of quantitation and lower than US-FDA or EU maximum residue levels.

Screening of multi-class antibiotics in pork meat by LC-Orbitrap-MS with modified QuEChERS extraction

The quantification capability of high resolution mass spectrometry is of great interest to analysts. We described a method for analysis of multi-class antibiotics in pork meat by UPLC-quadrupole (Q)-Orbitrap-MS. The QuEChERS approach with a clean-up step using a sorbent of primary-secondary amine (PSA) and C18 was adopted for sample preparation, and 37 antibiotics including beta-lactams, tetracyclines, sulfonamides, fluoroquinolones and macrolides were analyzed. The Q-Orbitrap method showed high sensitivity with limits of detection (LODs) ranging from 0.8 μg kg⁻¹ to 2.9 μg kg⁻¹. The method was further validated by intra and inter-day tests with fortified samples. Recovery (85–105.6%) and precision values (RSDs < 15%) for all analytes were obtained. The result indicates that UPLC-Q-Orbitrap-MS coupled with QuEChERS preparation can serve as a routine method for multi-class antibiotic analysis in pork meat.

The quantification capability of high resolution mass spectrometry is of great interest to analysts.