Unveiling Coformulants in Plant Protection Products by LC-HRMS Using a Polyhydroxy Methacrylate Stationary Phase.

A polyhydroxy methacrylate-based stationary reversed phase was used for the determination of coformulants in 20 plant protection products (PPPs). These samples were analyzed by liquid chromatography coupled to Q-Orbitrap high-resolution mass spectrometry (LC-Q-Orbitrap-HRMS) in full-scan MS and data-dependent acquisition (ddMS2) modes. A total of 92 coformulants were tentatively identified in these formulations by nontargeted and unknown analyses. Twelve out of them were quantified by analytical standards. The most concentrated coformulant was the anionic surfactant dodecylbenzenesulfonic acid, whose highest content was obtained in the Score 25 sample (6.87%, w/v). Furthermore, triethylene glycol monomethyl ether, 4-s-butyl-2,6-di-tert-butylphenol, 1-ethyl-2-pyrrolidone, sorbitan monostearate, 2,6-dimethylaniline, palmitamide, and N-lauryldiethanolamine were quantified for the first time in these products. Hence, the polyhydroxy methacrylate-based stationary phase increased the identification of new coformulants in PPPs, being complementary to conventional C18. This strategy could be applied in future studies to estimate potential coformulant residues from PPPs applied to crops.

Offline Solid-Phase Extraction and Separation of Mineral Oil Saturated Hydrocarbons and Mineral Oil Aromatic Hydrocarbons in Edible Oils, and Analysis via GC with a Flame Ionization Detector.

A method was developed for the determination of mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH) in edible oils, achieving similar limits of quantification than those obtained by online extraction methodologies, i.e., 0.5 mg/kg. The isolation of MOSH and MOAH was performed in a silver nitrated silica gel stationary phase prior to their analysis by gas chromatography-flame ionization detector (GC-FID). To improve the sensitivity, the simulated on-column injection method, using a suitable liner, was optimized. The method was validated at 0.5, 10.0 and 17.9 mg/kg, and recoveries ranged from 80 to 110%. Intra and inter-day precision were evaluated at the same levels, and relative standard deviation (RSD) was lower than 20%. The method was applied to a total of 27 samples of different types of oil previously analyzed in an accredited laboratory, detecting MOSH up to 79.2 mg/kg and MOAH up to 22.4 mg/kg.

An Innovative Metabolomic Approach for Golden Rum Classification Combining Ultrahigh-Performance Liquid Chromatography-Orbitrap Mass Spectrometry and Chemometric Strategies.

A comprehensive fingerprinting strategy for golden rum classification considering different categories such as fermentation barrel, raw material, and aging is provided, using a metabolomic fingerprinting approach. A nontarget fingerprinting of 30 different rums using liquid chromatography coupled to high-resolution mass spectrometry (Exactive Orbitrap mass analyzer, LC-HRMS) was applied. Principal component analysis (PCA) was used to assess the overall structure of the data and to identify potential outliers. Different chemometric analyses such as partial least-squares discriminant analysis (PLS-DA) were used. A variable importance in projection (VIP) selection method was applied to identify the most significant markers that allow group separation. Compounds related to aging and fermentation processes such as furfural derivates (e.g., hydroxymethylfurfural) and sugars (e.g., glucose, mannitol) were found as the most discriminant compounds (VIP threshold value >1.5). Suitable separation according to selected categories was achieved, and a classification ability of the models of close to 100% was achieved.

Determination of Calystegines in Several Tomato Varieties Based on GC-Q-Orbitrap Analysis and Their Classification by ANOVA.

In this study, several calystegines (A3, A5, B1, B2, B3, B4, and C1) were determined in tomato. A simple extraction followed by a derivatization step with silylating agents was performed prior to their analysis by gas chromatography coupled to high resolution mass spectrometry (GC-HRMS-Q-Orbitrap), which allowed the monitoring of several ions at accurate mass. The validation of the method has provided suitable values of linearity, trueness (73.7-120.0%), and precision (≤20.0%, except for calystegines B3 and B4 at 0.5 mg/kg). The limit of quantitation was set at 0.5 mg/kg for all analytes. The validated method was successfully applied to the analysis of nine different tomato varieties, and calystegines A3, A5, B2, and C1 were found at concentrations ranging between 0.65 mg/kg (C1) and 12.47 mg/kg (B2). Tomato varieties were classified according to their calystegines content by applying an analysis of variance (ANOVA).

Automated Determination of Xenobiotics (Pesticides, PCBs, PAHs, and PBDEs) in Sediment Samples Applying HS-SPME-GC-HRMS.

Background: Automated methods are needed for the reliable determination of xenobiotics in environmental samples. Objective: Optimization and application of an automated method for the ultra-trace analysis of 34 organic contaminants including polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), organochlorinated (OCPs), and organophosphorus pesticides (OPPs) in sediment samples have been performed. Methods: Automated method based on headspace solid-phase microextraction (SPME) coupled to GC-high-resolution MS (GC-HRMS) for the ultra-trace analysis of the targeted compounds has been developed. Conclusions: Suitable validation parameters in terms of linearity, trueness, selectivity, intraday and interday precision, LODs, and LOQs were obtained. Relative recovery values between 70 and 120% were achieved for all compounds (concentration levels assayed 1 and 10 µg/kg). RSD values were always lower than 25% for intra- and interday precision, and LODs and LOQs were 0.1 and 1.0 µg/kg, respectively, for all analytes. Highlights: The proposed method was applied to the analysis of sediments collected in Andalusia, Spain, and Poland, finding PCB 18 in one sample (15.9 µg/kg) and p,p'-DDE in several samples at concentrations ranging from 27.6 to 297.2 µg/kg.

Influence of storage conditions in the evolution of phytochemicals in nutraceutical products applying high resolution mass spectrometry.

An adequate knowledge about possible transformation of bioactive compounds in nutraceutical products during long storage is important in order to know potential modifications of this type of compounds. In this study, one year monitoring was performed in different types of nutraceutical products based on natural extracts (green tea, soy, royal jelly and grapes) observing the appearance of new bioactive compounds, which were not detected at the initial conditions, as well as the decrease of some of the detected compounds. To determine these transformation products, an analytical procedure based on high resolution mass spectrometry (Exactive-Orbitrap analyzer) was applied. It was noted that transformation products were detected after 3 months of storage in green tea and soy products, while 6 months were necessary to observe transformation products in royal jelly.

Quality control evaluation of nutraceutical products from Ginkgo biloba using liquid chromatography coupled to high resolution mass spectrometry.

Analysis of 11 commercial nutraceutical products obtained from ginkgo has been performed using ultra-high performance liquid chromatography coupled to single-stage Orbitrap high resolution mass spectrometry (UHPLC-Orbitrap-MS). The main phytochemicals present in these samples were detected and quantified, utilizing a database containing 65 compounds. Phytochemicals were extracted using a mixture of an aqueous solution of methanol:water (80:20, v/v) in two sequential solid-liquid extractions. Adequate validation parameters were obtained. The validated compounds exhibited suitable linearity with determination coefficients (R(2)) higher than 0.99, and intra and inter-day precision were lower than 17 and 22%, respectively. Limits of detection (LODs) and quantification (LOQs) were calculated, ranging from 2 to 10 µg L(-1), except for myricetin (LOD, 150 µg L(-1) and LOQ, 300 µg L(-1)). Results indicate that the amount of terpenoids greatly varies among samples, ranging from 1133 (C7) to 12706 mg kg(-1) (C11). This emphasizes the importance of improve quality control in ginkgo-based products. Moreover, retrospective analysis allowed the detection of some undesirable substances as ginkgolic acid in the samples evaluated.

Development and Validation of a Multiresidue Method for the Determination of Pesticides in Dry Samples (Rice and Wheat Flour) Using Liquid Chromatography/Triple Quadrupole Tandem Mass Spectrometry.

A rapid and sensitive multiresidue method was developed and validated for the determination of around 100 pesticides in dry samples (rice and wheat flour) by ultra-performance LC coupled to a triple quadrupole mass analyzer working in tandem mode (UPLC/QqQ-MS/MS). The sample preparation step was optimized for both matrixes. Pesticides were extracted from rice samples using aqueous ethyl acetate, while aqueous acetonitrile extraction [modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method] was used for wheat flour matrixes. In both cases the extracts were then cleaned up by dispersive solid phase extraction with MgSO4 and primary secondary amine+C18 sorbents. A further cleanup step with Florisil was necessary to remove fat in wheat flour. The method was validated at two concentration levels (3.6 and 40 µg/kg for most compounds), obtaining recoveries ranging from 70 to 120%, intraday and interday precision values≤20% expressed as RSDs, and expanded uncertainty values≤50%. The LOQ values ranged between 3.6 and 20 µg/kg, although it was set at 3.6 µg/kg for the majority of the pesticides. The method was applied to the analysis of 20 real samples, and no pesticides were detected.

Identification of transformation products of pesticides and veterinary drugs in food and related matrices: use of retrospective analysis.

Retrospective analysis has been applied in different samples, including honey, meat, feed and nutraceutical products from ginkgo biloba, soya, royal jelly and green tea, with the aim of searching transformation products of pesticides and veterinary drugs, which were not included in an initial analysis. Generic extraction and analytical procedures based on high resolution mass spectrometry (Exactive-Orbitrap analyser was used) have been applied. All obtained data have been reprocessed and some compounds as anhydroerythromycin in honey and 3,5,6-trichloro-2-pyridinol in feed have been detected, demonstrating the applicability and the utility of the procedure. Advantages and disadvantages of retrospective approach have been highlighted.

Systematic Study of the Content of Phytochemicals in Fresh and Fresh-Cut Vegetables.

Vegetables and fruits have beneficial properties for human health, because of the presence of phytochemicals, but their concentration can fluctuate throughout the year. A systematic study of the phytochemical content in tomato, eggplant, carrot, broccoli and grape (fresh and fresh-cut) has been performed at different seasons, using liquid chromatography coupled to triple quadrupole mass spectrometry. It was observed that phenolic acids (the predominant group in carrot, eggplant and tomato) were found at higher concentrations in fresh carrot than in fresh-cut carrot. However, in the case of eggplant, they were detected at a higher content in fresh-cut than in fresh samples. Regarding tomato, the differences in the content of phenolic acids between fresh and fresh-cut were lower than in other matrices, except in winter sampling, where this family was detected at the highest concentration in fresh tomato. In grape, the flavonols content (predominant group) was higher in fresh grape than in fresh-cut during all samplings. The content of glucosinolates was lower in fresh-cut broccoli than in fresh samples in winter and spring sampling, although this trend changes in summer and autumn. In summary, phytochemical concentration did show significant differences during one-year monitoring, and the families of phytochemicals presented different behaviors depending on the matrix studied.

Fast analysis of polyphenols in royal jelly products using automated TurboFlow™-liquid chromatography-Orbitrap high resolution mass spectrometry.

This study describes the development of a novel, simple and fast analytical method for the detection and quantification of polyphenols in royal jelly products, using an in-house database containing more than 50 compounds. The extraction method consisted of sample dilution, followed by a fast on-line system composed of turbulent flow chromatography (TurboFlow™) coupled to liquid chromatography (LC)-Exactive-Orbitrap analyzer. The total run time was 18min, including automated extraction, analytical chromatography and re-equilibration. The method was validated obtaining limits of quantification (LOQ) ranging from 10 to 150µg/kg. The linearity range was up to 2000µg/L and determination coefficients (R2) were higher than 0.994. Adequate recoveries were obtained at three concentration levels (500, 1000 and 2000µg/kg). This method was applied to the analysis of nine samples and the concentration of polyphenols ranged from 14 (apigenin) to 18,936µg/kg (ferulic acid).

Highly sensitive determination of polybrominated diphenyl ethers in surface water by GC coupled to high-resolution MS according to the EU Water Directive 2008/105/EC.

The analysis of brominated flame retardants, such as polybrominated diphenyl ethers (PBDEs), has received increased interest because of their toxicity and ubiquity. According to European Union Directive 2008/105/EC, the development of highly sensitive and selective methods capable of determining PBDEs at low concentration levels (<0.5 ng/L) is necessary. In this work, an SPE method was developed for the analysis of the six PBDEs (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154) specified by the aforementioned directive in surface waters. The analyses were performed by GC coupled to magnetic sector high-resolution MS. The conditions were also optimized to detect the target compounds in water samples at concentrations below the environmental quality standards established by European legislation. The validated method provided adequate linearity (determination coefficient, R(2) ≥ 0.9960), recovery (101-120%, except for BDE-47 at 5 ng/L, 127%), and precision values (RSD < 20%) at two fortification levels (0.2 and 5 ng/L). The method showed LODs and LOQs ranging from 0.02 to 0.05 and from 0.05 to 0.1 ng/L, respectively. The method was applied in surface water samples, allowing the determination of these compounds at the limits established by current legislation.

Multiclass determination of phytochemicals in vegetables and fruits by ultra high performance liquid chromatography coupled to tandem mass spectrometry.

In this study a simultaneous determination of several classes of phytochemicals (isoflavones, glucosinolates, flavones, flavonols and phenolic acids) in tomato, broccoli, carrot, eggplant and grape has been carried out by ultra high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). Solid-liquid extraction assisted by rotary agitator was utilised, using a mixture of methanol:water (80:20, v/v) as solvent. The analytical procedure was validated in all the matrices, obtaining recoveries ranging from 60% to 120% with repeatability values (expressed as relative standard deviations, RSDs) lower than 25%. Limits of quantification (LOQs) were always equal or lower than 50µg/kg, except for some glucosinolates (125µg/kg). Finally the method was applied to different matrices such as tomato, broccoli, carrot, grape and eggplant, observing that chlorogenic acid was detected in most of the samples at higher concentrations in relation to the other compounds.

Multi-mycotoxin determination in cereals and derived products marketed in Tunisia using ultra-high performance liquid chromatography coupled to triple quadrupole mass spectrometry.

The aim of the study was the use of a fast and simple method using ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) for the simultaneous determination of aflatoxins (AFB1, AFB2, AFG1 and AFG2), ochratoxin A (OTA), fumonisins (FB1 and FB2), deoxynivalenol (DON), T2 and HT2 toxins in 58 samples of raw wheat (n = 34), barley (n = 5), sorghum (n = 3), processed wheat (n = 13) and breakfast cereals (n = 3) from Tunisian markets. The frequency of contamination of total samples with the analyzed mycotoxins was 50%. AFG2 was the most frequently detected in 11 samples (4 wheat, 4 barley and 3 sorghum) and it was detected at 5.2-52.4 µg/kg. HT2 toxin contaminated seven samples (4 wheat and 3 barley) and it was detected at 5.0-11.1 µg/kg. FB2 was detected in one wheat, sorghum, semolina and breakfast cereal samples at 5.0-61.5 µg/kg. FB1 was detected in three samples (2 sorghum and one barley) at 6.4-120 µg/kg. AFB1 was only found in two sorghum samples at 14 and 79.9 µg/kg. OTA was detected in one sorghum sample at concentrations below limit of quantification (5 µg/kg). The analytical results also showed that all the analyzed samples were not contaminated with DON, AFG1, AFB2 and T2 toxin.

Multiresidue determination of veterinary drugs in aquaculture fish samples by ultra high performance liquid chromatography coupled to tandem mass spectrometry.

A simple, selective and fast multiresidue method was developed for the determination of 32 veterinary drug residues belonging to several families, in gilthead sea bream (Sparus aurata) by ultra high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). The extraction was based on modified QuEChERS (quick, easy, cheap, effective, rugged and safe) procedure, using as extraction solution a mixture of acetonitrile and methanol (75:25, v/v), and it reduces sample handling, increasing sample throughput in relation to current methodologies. The developed method was validated and mean recovery ranged from 69% to 125% (at 10, 25, 50 and 100 µg/kg). Intra and interday precision, estimated as the same levels and expressed as relative standard deviation, RSD, were lower than 20% and 30%, respectively. Limits of detection (LODs) and quantification (LOQs) were lower than 7.5 and 25 µg/kg, respectively, except for danofloxacin, oxytetracycline and tetracycline (LOD and LOQ of 15.0 and 50 µg/kg, respectively). Decision limit (CC(α)) and detection capability (CC(ß)) were also calculated and ranged from 16.7 µg/kg (levamisole) to 605.0 (flumequine) µg/kg and from 23.5 µg/kg (levamisole) to 611.5 µg/kg (flumequine), respectively. The expanded uncertainty, U, was also evaluated ant it was below 25% at 100 µg/kg level, except for tetracycline (28%). Finally, the method was applied to ten samples obtained from local supermarkets in Almería (Spain) and traces of some compounds were detected.

Development and validation of a multiclass method for the determination of veterinary drug residues in chicken by ultra high performance liquid chromatography-tandem mass spectrometry.

A multiclass method has been optimized and validated for the simultaneous determination of 20 veterinary drug residues belonging to several classes, as quinolones, sulfonamides, macrolides, anthelmintics, avermectins and diamino derivatives, and benzathine, used as a marker of the presence of penicillin, in muscle chicken. It has been based on QuEChERS methodology (quick, easy, cheap, effective, rugged and safe) and ultra high performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry (UHPLC-MS/MS). Several chromatographic conditions were optimized, obtaining a running time <8.5 min. The developed method was validated on the basis of international guidelines. Mean recoveries ranged from 70 to 120%, except for benzathine (65.6% at 20 µg kg(-1)) and sulfadimidine (69.0% at 100 µg kg(-1)). Repeatability was lower than 20.0% except for sulfachlorpyridazine (22.1% at 20 µg kg(-1)) and tylosin (20.5% and 20.6% at 30 and 50 µg kg(-1), respectively), whereas reproducibility was lower than 25% except for flumequine (27.4% at 20 µg kg(-1)) and benzathine (37.8% and 27% at 20 and 50 µg kg(-1), respectively). Limits of detection (LODs) and quantification (LOQs) ranged from 3.0 to 6.0 µg kg(-1) and 10.0 to 20.0 µg kg(-1), respectively, except for tylosin that showed a LOD and LOQ of 9.0 and 30.0 µg kg(-1). Decision limit (CC(α)) and detection capability (CC(ß)) were calculated and CC(ß) ranged from 24.1 µg kg(-1) (mebendazole) to 423.6 µg kg(-1) (flumequine). Finally, the method was applied to real samples and traces of some compounds were found in eight samples of chicken and benzathine was detected in one sample at 29.9 µg kg(-1).

Single solid phase extraction method for the simultaneous analysis of polar and non-polar pesticides in urine samples by gas chromatography and ultra high pressure liquid chromatography coupled to tandem mass spectrometry.

A new multiresidue method has been developed and validated for the simultaneous extraction of more than two hundred pesticides, including non-polar and polar pesticides (carbamates, organochlorine, organophosphorous, pyrethroids, herbicides and insecticides) in urine at trace levels by gas and ultra high pressure liquid chromatography coupled to ion trap and triple quadrupole mass spectrometry, respectively (GC-IT-MS/MS, UHPLC-QqQ-MS/MS). Non-polar and polar pesticides were simultaneously extracted from urine samples by a simple and fast solid phase extraction (SPE) procedure using C(18) cartridges as sorbent, and dichloromethane as elution solvent. Recovery was in the range of 60-120%. Precision values expressed as relative standard deviation (RSD) were lower than 25%. Identification and confirmation of the compounds were performed by the use of retention time windows, comparison of spectra (GC-amenable compounds) or the estimation of the ion ratio (LC-amenable compounds). For GC-amenable pesticides, limits of detection (LODs) ranged from 0.001 to 0.436 µg L(-1) and limits of quantification (LOQs) from 0.003 to 1.452 µg L(-1). For LC-amenable pesticides, LODs ranged from 0.003 to 1.048 µg L(-1) and LOQs ranged from 0.011 to 3.494 µg L(-1). Finally, the optimized method was applied to the analysis of fourteen real samples of infants from agricultural population. Some pesticides such as methoxyfenozide, tebufenozide, piperonyl butoxide and propoxur were found at concentrations ranged from 1.61 to 24.4 µg L(-1), whereas methiocarb sulfoxide was detected at trace levels in two samples.

Determination of 19 volatile organic compounds in wastewater effluents from different treatments by purge and trap followed by gas-chromatography coupled to mass spectrometry.

A rapid and simple methodology based on purge and trap with gas-chromatography coupled to triple quadrupole mass spectrometry has been developed for the analysis of 19 volatile organic compounds (VOCs) in wastewater (WW) effluents from four different treatments. The determination was carried out in the raw WW effluents, which were not submitted to any pre-treatment (e.g., filtration). A matrix effect study was also performed, concluding that solvent calibration was adequate to quantify VOCs in WW effluent samples containing a variety of suspended particulate matter. Adequate validation parameters were obtained with recovery values in the range 73-124% and precision values lower than 24%. Limits of quantification were established at 0.1 µg L(-1) for all VOCs. The proposed method was applied to the analysis of WW samples, detecting chloroform and toluene at concentrations ranging from 0.1 to 4.80 µg L(-1).

QuEChERS-based extraction procedure for multifamily analysis of phytohormones in vegetables by UHPLC-MS/MS.

A new method has been developed and validated for the simultaneous analysis of different phytohormones (auxins, cytokinins and gibberellins) in vegetables. The compounds were extracted using a QuEChERS-based method (acronym of quick, easy, cheap, effective, rugged and safe). The separation and determination of the selected phytohormones were carried out by ultra high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS), using electrospray ionization source (ESI) in positive and negative ion modes. The method was validated and mean recoveries were evaluated at three concentration levels (50, 100 and 250 µg/kg), ranging from 75 to 110% at the three levels assayed. Intra- and interday precisions, expressed as relative standard deviations (RSDs), were lower than 20 and 25%, respectively. Limits of quantification (LOQs) were equal or lower than 10 µg/kg. The developed procedure was applied to seven courgette samples, and naphthylacetic acid, naphthylacetamide and benzyladenine were found in some of the analysed samples.

Multi-mycotoxin analysis in eggs using a QuEChERS-based extraction procedure and ultra-high-pressure liquid chromatography coupled to triple quadrupole mass spectrometry.

A reliable and rapid method has been developed for the determination of 10 mycotoxins (beauvericin, enniatin A, A1, B1, citrinin, aflatoxin B1, B2, G1, G2 and ochratoxin A) in eggs at trace levels. Ultra-high-pressure liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) has been used for the analysis of these compounds in less than 7 min. Mycotoxins have been extracted from egg samples using a QuEChERS-based extraction procedure (Quick, Easy, Cheap, Effective, Rugged and Safe) without applying any further clean-up step. Extraction, chromatographic and detection conditions were optimised in order to increase sample throughput and sensitivity. Matrix-matched calibration was used for quantification. Blank samples were fortified at 10, 25, 50 and 100 µg kg(-1), and recoveries ranged from 70% to 110%, except for ochratoxin A and aflatoxin G1 at 10 µg kg(-1), and aflatoxin G2 at 50 µg kg(-1). Relative standard deviations were lower than 25% in all the cases. Limits of detection ranged from 0.5 µg kg(-1) (for aflatoxins B1, B2 and G1) to 5 µg kg(-1) (for enniatin A, citrinin and ochratoxin A) and limits of quantification ranged from 1 µg kg(-1) (for aflatoxins B1, B2 and G1) to 10 µg kg(-1) (for enniatin A, citrinin and ochratoxin A). Seven samples were analyzed and aflatoxins B1, B2, G1, G2, and beauvericin were detected at trace levels.