Multi-residue determination of 115 veterinary drugs and pharmaceutical residues in milk powder, butter, fish tissue and eggs using liquid chromatography-tandem mass spectrometry

A simple and sensitive multi-residue method for the determination of 115 veterinary drugs and pharmaceuticals, belonging in more than 20 different classes, in butter, milk powder, egg and fish tissue has been developed. The method involves a simple generic solid-liquid extraction step (solvent extraction, SE) with 0.1% formic acid in aqueous solution of EDTA 0.1% (w/v)-acetonitrile (ACN)-methanol (MeOH) (1:1:1, v/v) with additional ultrasonic-assisted extraction. Precipitation of lipids and proteins was promoted by subjecting the extracts at very low temperature (-23°C) for 12h. Further cleanup with hexane ensures fat removal from the matrix. Analysis was performed by liquid chromatography coupled with electrospray ionization and tandem mass spectrometry (LC-ESI-MS/MS). Two separate runs were performed for positive and negative ionization in multiple reaction monitoring mode (MRM). Particular attention was devoted to extraction optimization: different sample-to-extracting volume ratios, different concentrations of formic acid in the extraction solvent and different ultrasonic extraction temperatures were tested in butter, egg and milk powder samples. The method was also applied in fish tissue samples. It was validated, on the basis of international guidelines, for all four matrices. Quantitative analysis was performed by means of standard addition calibration. For over 80% of the analytes, the recoveries were between 50% and 120% in all matrices studied, with RSD values in the range of 1-18%. Limits of detection (LODs) and quantification (LOQs) ranged from 0.008μgkg-1 (oxfendazole in butter) to 3.15μgkg-1 (hydrochlorthiazide in egg). The evaluated method provides reliable screening, quantification, and identification of 115 veterinary drug and pharmaceutical residues in foods of animal origin and has been successfully applied in real samples. © 2015 Elsevier B.V.

Multi-residue determination of seventeen sulfonamides and five tetracyclines in fish tissue using a multi-stage LC-ESI-MS/MS approach based on advanced mass spectrometric techniques

A strategy was newly developed to rapidly screen seventeen sulfonamides and five tetracyclines in a single run from fish tissues using ultra-high performance liquid chromatography (UHPLC) coupled with comprehensive mass spectrometric approaches, including precursor-ion scan and data dependent scan. The product ions for precursor-ion scanning were selected by studying the MS/MS fragmentation of the analytes. All sulfonamides share the same diagnostic product ion at m/z 156 in positive MS/MS scan, while for tetracycline antibiotics the diagnostic product ion was proved to be at m/z 153.8. Further characterization of each compound was performed using a data dependent scan. Separation was performed on a Zorbax Eclipse Plus C18 column with a gradient elution using acetonitrile - 0.1% formic acid mobile phase at a flow rate of 0.1mLmin-1. This approach has proven to be a powerful, highly selective, and sensitive tool for rapid screening and detection of non-targeted components in fish tissue and requires a minimum sample preparation such as one generic extraction step with MeOH:ACN 50:50 (v/v) acidified with 0.05% formic acid. The method has also been applied successfully to porcine and poultry meat. The validation of such a screening method was performed for the first time according to Commission Decision 2002/657/EC and satisfactory method performance characteristics were achieved. © 2010 Elsevier B.V

Ionization study and simultaneous determination of avermectins and milbemycines in fish tissue by LC-ESI-MS/MS

In this study, the simultaneous determination of avermectins (emamectin, eprinomectin, abamectin, doramectin and ivermectin) and milbemycines (moxidectin) in fish tissue with LC-ESI-MS/MS, was studied. Optimum chromatographic separation of target analytes was achieved using a Waters Acquity UPLC BEH C18 (100 mm × 2.1 mm, 1.7 mm) analytical column, operated at 40 °C and the composition of the mobile phase used was (A): ACN-MeOH (0.1% HCOOH) (1:1) and (B): 1 mM HCOONH4 (0.1% HCOOH). Various mobile phases were tested and the effect of the mobile phase composition on the analytes ionization was thoroughly examined in an extensive ionization study, aiming to increase the analytes' sensitivity. Deuterated ivermectin (IVR-d2) was used as an internal standard (IS). Avermectin's and milbemycine's extraction from the fish matrix was conducted with acidified ACN (0.1% HCOOH), followed by QuEChERS methodology. The method developed herein was validated according to the European Legislation requirements (Commission Decision 657/2002/EC) and recoveries ranged from 86 to 106% for all target analytes, with relative standard deviations < 20%. LODs ranged from 0.07 μg/kg (emamectin) to 1.3 μg/kg (doramectin), indicating the excellent sensitivity of the method. The developed methodology was successfully applied to fish samples obtained from aquaculture. © 2018 Elsevier B.V

Analysis of 76 veterinary pharmaceuticals from 13 classes including aminoglycosides in bovine muscle by hydrophilic interaction liquid chromatography–tandem mass spectrometry

A multiresidue/multiclass method for the simultaneous determination of 76 veterinary drugs and pharmaceuticals in bovine muscle tissue has been developed and validated according to the requirements of European Commission Decision 2002/657/EC. The analytes belong in 13 different classes, including aminoglycoside antibiotics, whose different physicochemical properties (extremely polar character) render their simultaneous determination with other veterinary drugs quite problematic. The method combines a two-step extraction procedure (extraction with acetonitrile followed by an acidic aqueous buffer extraction) with hydrophilic interaction liquid chromatography–tandem mass spectrometry (HILIC–MS/MS) determination, allowing confirmation and quantification in a single chromatographic run. Further cleanup with solid phase extraction was performed using polymeric SPE cartridges. A thorough ionization study of aminoglycosides was performed in order to increase their sensitivity and significant differences in the abundance of the precursor ions of the analytes were revealed, depending on the composition of the mobile phase tested. Further gradient elution optimization and injection solvent optimization were performed for all target analytes.The method was validated according to the European Commission Decision 2002/657. Quantitative analysis was performed by means of standard addition calibration. Recoveries varied from 37.4% (bromhexine) to 106% (kanamycin) in the lowest validation level and 82% of the compounds showed recovery >70%. Detection capability (CCβ) varied from 2.4 (salinomycin) to 1302 (apramycin) μg kg−1. © 2016 Elsevier B.V

Qualitative multiresidue screening method for 143 veterinary drugs and pharmaceuticals in milk and fish tissue using liquid chromatography quadrupole-time-of-flight mass spectrometry

A wide-scope screening methodology has been developed for the identification of veterinary drugs and pharmaceuticals in fish tissue and milk using ultrahigh-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF MS). The method was validated using a qualitative approach at two concentration levels. The detection of the residues was accomplished by retention time, accurate mass, and the isotopic fit using an in-house database. Product-ion spectra were used for unequivocal identification of the compounds. Generic sample treatment was applied. The majority of the compounds were successfully detected and identified at concentration levels of 150 ng mL-1 in milk and 200 μg kg-1 in fish (>80% of the compounds in both matrices), whereas satisfactory results were also obtained at concentration levels of 15 ng mL-1 in milk and 20 μg kg-1 in fish (>60% of the compounds detected and identified). © 2015 American Chemical Society

Liquid chromatography–tandem mass spectrometric methods for the determination of spinosad, thiacloprid and pyridalyl in spring onions and estimation of their pre-harvest interval values

Two liquid chromatography–tandem mass spectrometric methods were developed and validated to determine spinosyn A and D, thiacloprid and pyridalyl in spring onions cultivated under Egyptian field conditions. The degradation rates, the pre-harvest interval (PHI) values and the half-life values of the three pesticides were estimated. QuEChERS was used for sample preparation and the separation was performed on an X-Bridge C18 column with ACN-formic acid 0.1% as the mobile phase. Linear range, method detection limits (MDLs), precision, recovery and matrix effects were estimated. The multi-residue MDLs ranged from 0.02 μg/kg (spinosyn A & D) to 0.05 μg/kg for pyridalyl. All the investigated pesticides showed high degradation rates. For spinosad the half-life value was 1.2 days, for thiacloprid it reached 2.2 days and for pyridalyl 4.4 days. Furthermore, the calculated PHI values, according to the maximum residue levels set by the EU, were 0 days for spinosad, 9.8 days for thiacloprid and 39.4 days for pyridalyl. © 2016 Elsevier Lt

Application of High Resolution Mass Spectrometric methods coupled with chemometric techniques in olive oil authenticity studies - A review

Extra Virgin Olive Oil (EVOO), the emblematic food of the Mediterranean diet, is recognized for its nutritional value and beneficial health effects. The main authenticity issues associated with EVOO's quality involve the organoleptic properties (EVOO or defective), mislabeling of production type (organic or conventional), variety and geographical origin, and adulteration. Currently, there is an emerging need to characterize EVOOs and evaluate their genuineness. This can be achieved through the development of analytical methodologies applying advanced “omics” technologies and the investigation of EVOOs chemical fingerprints. The objective of this review is to demonstrate the analytical performance of High Resolution Mass Spectrometry (HRMS) in the field of food authenticity assessment, allowing the determination of a wide range of food constituents with exceptional identification capabilities. HRMS-based workflows used for the investigation of critical olive oil authenticity issues are presented and discussed, combined with advanced data processing, comprehensive data mining and chemometric tools. The use of unsupervised classification tools, such as Principal Component Analysis (PCA) and Hierarchical Clustering Analysis (HCA), as well as supervised classification techniques, including Linear Discriminant Analysis (LDA), Support Vector Machine (SVM), Partial Least Square Discriminant Analysis (PLS-DA), Orthogonal Projection to Latent Structure-Discriminant Analysis (OPLS-DA), Counter Propagation Artificial Neural Networks (CP-ANNs), Self-Organizing Maps (SOMs) and Random Forest (RF) is summarized. The combination of HRMS methodologies with chemometrics improves the quality and reliability of the conclusions from experimental data (profile or fingerprints), provides valuable information suggesting potential authenticity markers and is widely applied in food authenticity studies. © 2020 Elsevier B.V

Development of Specific LC-ESI-MS/MS Methods to Determine Bifenthrin, Lufenuron, and Iprodione Residue Levels in Green Beans, Peas, and Chili Peppers Under Egyptian Field Conditions

The dissipation of bifenthrin, lufenuron, and iprodione was studied in green beans, peas, and chilli peppers under Egyptian field conditions. For this purpose, three specific and one multi-analyte liquid chromatography-electrospray ionization-tandem mass spectrometry methods were developed and validated according to SANCO guidelines for the determination of bifenthrin, iprodione, and lufenuron residues in the selected commodities. Sample preparation was carried out by the QuEChERs approach, and determination was performed in positive ionization mode for iprodione and bifenthrin and in negative mode for lufenuron. Optimization of the ionization parameters and the chromatographic conditions was performed for each method developed. All methods showed satisfactory performance criteria. Linear dynamic range, limits of detection (LOD) and quantification (LOQ), precision, recovery, and matrix effects were estimated, and the calculated LODs were in the micrograms-per-kilogram range, namely 0.14, 0.61, and 1.4 μg/kg for bifenthrin, lufenuron, and iprodione, respectively. Field trials were carried out in one of the biggest farms in Egypt (Blue Nile) that exports significant quantities of vegetables to the European Union (EU) countries. All the examined pesticides showed high degradation rates. The t 1/2 values for bifenthrin were 3.3, 2.1, and 9.6 days in green beans, peas, and chili peppers, respectively. For iprodione, they reached 2.4 and 14.4 days in green beans and peppers. Furthermore, the calculated pre-harvest interval (PHI) values, according to the maximum residue limits set by EU, were 0, 4, and 0 days for bifenthrin in green beans, peas, and peppers, respectively, and for iprodione, 2 days in green beans and 0 days in peppers. In case of lufenuron, no t 1/2 and PHI were estimated as no residues were found in all pea samples. © 2012 Springer Science+Business Media New York

Authentication of Greek PDO kalamata table olives: A novel non-target high resolution mass spectrometric approach

Food science continually requires the development of novel analytical methods to prevent fraudulent actions and guarantee food authenticity. Greek table olives, one of the most emblematic and valuable Greek national products, are often subjected to economically motivated fraud. In this work, a novel ultra-high-performance liquid chromatography–quadrupole time of flight tandem mass spectrometry (UHPLC-QTOF-MS) analytical method was developed to detect the mislabeling of Greek PDO Kalamata table olives, and thereby establish their authenticity. A non-targeted screening workflow was applied, coupled to advanced chemometric techniques such as Principal Component Analysis (PCA) and Partial Least Square Discriminant Analysis (PLS-DA) in order to fingerprint and accurately discriminate PDO Greek Kalamata olives from Kalamata (or Kalamon) type olives from Egypt and Chile. The method performance was evaluated using a target set of phenolic compounds and several validation parameters were calculated. Overall, 65 table olive samples from Greece, Egypt, and Chile were analyzed and processed for the model development and its accuracy was validated. The robustness of the chemometric model was tested using 11 Greek Kalamon olive samples that were produced during the following crop year, 2018, and they were successfully classified as Greek Kalamon olives from Kalamata. Twenty-six characteristic authenticity markers were indicated to be responsible for the discrimination of Kalamon olives of different geographical origins. © 2020 by the authors