Fabric phase sorptive extraction followed by ultra-performance liquid chromatography-tandem mass spectrometry for the determination of fungicides and insecticides in wine

Development of highly hydrophobic fabric phase sorptive extraction membranes and exploring their applications for the rapid determination of tocopherols in edible oils analyzed by high pressure liquid chromatography-diode array detection

Α novel, green, and facile fabric phase sorptive extraction (FPSE) prior to high pressure liquid chromatography with diode array detection (HPLC-DAD) methodology was developed for the efficient extraction and quantitative determination of tocopherols (α-, sum of (β+γ), and δ-) in edible oils. Among several highly hydrophobic FPSE membranes, sol-gel polycaprolactone-polydimethylsiloxane-polycaprolactone (sol-gel PCAP-PDMS-PCAP) coated polyester FPSE membrane was found as the most efficient in extracting tocopherol homologues from edible oil samples. To maximize the extraction efficiency of FPSE membrane, major parameters of FPSE including the membrane size, sample loading time, the choice of the appropriate elution solvent and the elution solvent volume, desorption time, and the influence of stirring were systematically optimized. The developed FPSE-HPLC-DAD methodology was validated and presented adequately low limits of detection (LODs) and limits of quantification (LOQs) over the ranges 0.05-0.10 μg/g, and 0.17-0.33 μg/g, respectively. The RSD% of the within-day and between-day assays were lower than 1.3, and 11.8, respectively, demonstrating good method precision. The trueness of the method was assessed by means of relative percentage of recovery and ranged between 90.8 and 95.1% for within-day assay, and between 88.7-92.8% for between-day assay. The developed methodology was applied in the analysis of edible oils.

Direct determination of boscalid in grape samples by differential pulse voltammetry using a carbon paste electrode

A new methodology to determine directly the fungicide boscalid (BSC) was developed and successfully applied in red grape 100% juice, peel extracts, pulp and purple grape seeds (Vitis labrusca L.) with a working carbon paste electrode (CPE) without sample preparation. Cyclic voltammetry (CV) indicated the presence of an irreversible cathodic process of BSC at -1.21 V vs. Ag|AgCl (KCl 3.0 mol L^-1) in a solution of 0.100 mol L^-1 HCl/acetone 70 : 30 (v/v). This behavior was also observed using Square Wave Voltammetry (SWV). The Differential Pulse Voltammetry (DPV) technique proved to be more sensitive and with higher selectivity for BSC quantification. The influence of pH on the reduction of BSC was investigated in Britton-Robinson Buffer (BRB), 0.01 mol L^-1 (pH 2.00-12.00). The limit of detection (LOD) values obtained from calibration curves for different samples were as follows: 0.107 mg L^-1 for deionized water; 0.146 mg L^-1 for red grape 100% juice; 0.922 mg kg^-1 for peel extracts; 0.818 mg kg^-1 for grape pulp and 0.691 mg kg^-1 for grape seeds. The corresponding Limit of Quantification (LOQ) values for the same samples were as follows: 0.358 mg L^-1; 0.486 mg L^-1; 2.87 mg kg^-1; 2.73 mg kg^-1 and 2.51 mg kg^-1, respectively. In addition, the recovery rates for the different concentration levels in the investigated range varied between 97.13 and 103.4%. All tests performed with the samples did not require extraction or pre-concentration steps of BSC, resulting in a fast, simple and cheap methodology.

Fabric Phase Sorptive Extraction: A Paradigm Shift Approach in Analytical and Bioanalytical Sample Preparation

Fabric phase sorptive extraction (FPSE) is an evolutionary sample preparation approach which was introduced in 2014, meeting all green analytical chemistry (GAC) requirements by implementing a natural or synthetic permeable and flexible fabric substrate to host a chemically coated sol-gel organic-inorganic hybrid sorbent in the form of an ultra-thin coating. This construction results in a versatile, fast, and sensitive micro-extraction device. The user-friendly FPSE membrane allows direct extraction of analytes with no sample modification, thus eliminating/minimizing the sample pre-treatment steps, which are not only time consuming, but are also considered the primary source of major analyte loss. Sol-gel sorbent-coated FPSE membranes possess high chemical, solvent, and thermal stability due to the strong covalent bonding between the fabric substrate and the sol-gel sorbent coating. Subsequent to the extraction on FPSE membrane, a wide range of organic solvents can be used in a small volume to exhaustively back-extract the analytes after FPSE process, leading to a high preconcentration factor. In most cases, no solvent evaporation and sample reconstitution are necessary. In addition to the extensive simplification of the sample preparation workflow, FPSE has also innovatively combined the extraction principle of two major, yet competing sample preparation techniques: solid phase extraction (SPE) with its characteristic exhaustive extraction, and solid phase microextraction (SPME) with its characteristic equilibrium driven extraction mechanism. Furthermore, FPSE has offered the most comprehensive cache of sorbent chemistry by successfully combining almost all of the sorbents traditionally used exclusively in either SPE or in SPME. FPSE is the first sample preparation technique to exploit the substrate surface chemistry that complements the overall selectivity and the extraction efficiency of the device. As such, FPSE indeed represents a paradigm shift approach in analytical/bioanalytical sample preparation. Furthermore, an FPSE membrane can be used as an SPME fiber or as an SPE disk for sample preparation, owing to its special geometric advantage. So far, FPSE has overwhelmingly attracted the interest of the separation scientist community, and many analytical scientists have been developing new methodologies by implementing this cutting-edge technique for the extraction and determination of many analytes at their trace and ultra-trace level concentrations in environmental samples as well as in food, pharmaceutical, and biological samples. FPSE offers a total sample preparation solution by providing neutral, cation exchanger, anion exchanger, mixed mode cation exchanger, mixed mode anion exchanger, zwitterionic, and mixed mode zwitterionic sorbents to deal with any analyte regardless of its polarity, ionic state, or the sample matrix where it resides. Herein we present the theoretical background, synthesis, mechanisms of extraction and desorption, the types of sorbents, and the main applications of FPSE so far according to different sample categories, and to briefly show the progress, advantages, and the main principles of the proposed technique.

Analytical methods to analyze pesticides and herbicides

This paper reviews studies published in 2019, in the area of analytical techniques for determination of pesticides and herbicides. It should be noted that some of the reports summarized in this review are not directly related to but could potentially be used for water environment studies. Based on different methods, the literatures are organized into six sections, namely extraction methods, electrochemical techniques, spectrophotometric techniques, chemiluminescence and fluorescence methods, chromatographic and mass spectrometric techniques, and biochemical assays. PRACTITIONER POINTS: Totally 141 research articles have been summarized. The review is divided into six parts. Chromatographic and mass spectrometric techniques are the most widely used methods.

Fabric phase sorptive extraction for the determination of 17 multiclass fungicides in environmental water by gas chromatography-tandem mass spectrometry

A rapid environmental pollution screening and monitoring workflow based on fabric phase sorptive extraction-gas chromatography-tandem mass spectrometry (FPSE-GC-MS/MS) is proposed for the first time for the analysis of 17 widespread used fungicides (metalaxyl, cyprodinil, tolylfluanid, procymidone, folpet, fludioxonil, myclobutanil, kresoxim methyl, iprovalicarb, benalaxyl, trifloxystrobin, fenhexamid, tebuconazole, iprodione, pyraclostrobin, azoxystrobin and dimethomorph) in environmental waters. The most critical parameters affecting FPSE, such as sample volume, matrix pH, desorption solvent and time, and ionic strength were optimized by statistical design of experiment to obtain the highest extraction efficiency. Under the optimized conditions, the proposed FPSE-GC-MS/MS method was validated in terms of linearity, repeatability, reproducibility, accuracy and precision. To assess matrix effects, recovery studies were performed employing different water matrices including ultrapure, fountain, river, spring, and tap water at 4 different concentration levels (0.1, 0.5, 1 and 5 µg/L). Recoveries were quantitative with values ranging between 70-115%, and relative standard deviation values lower than 14%. Limits of quantification were at the low ng/L for all the target fungicides. Finally, the validated FPSE-GC-MS/MS method was applied to real water samples, revealing the presence of 11 out of the 17 target fungicides.

Monitoring of 49 Pesticides and 17 Mycotoxins in Wine by QuEChERS and UHPLC-MS/MS Analysis

An effective method for the determination of 49 pesticide residues and 17 mycotoxins in wine by a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method and ultrahigh-performance liquid chromatography-tandem mass spectrometry was developed. The target compounds were extracted with 1% (v/v) formic acid-acetonitrile, and no cleanup steps were required. The extracts were separated on a C18 chromatographic column (2.1 mm × 50 mm, 1.7 µm) with acetonitrile and water with 0.2% formic acid solution and ammonium acetate (10 mM) as the mobile phases under gradient elution at a flow rate of 0.2 mL/min. The determination was conducted using electrospray ionization in positive ion mode with multiple reaction monitoring. The analytes were quantified by comparison with matrix-matched standard solutions. The good linearities were obtained in the range of 0.05 to 500.0 µg/kg, and the correlation coefficients were all greater than 0.9935. The average recoveries of the 66 target compounds ranged from 69% to 119%, and the RSDs were in the range of 1% to 10%. The limits of detection were in the range of 0.05 to 20.0 µg/kg. The method was proved to be rapid, selective, sensitive, and stable, and it has been applied to analysis of 64 wine samples.