Critical assessment of performance characteristics of methods applicable in determination of multiple residues of modern pesticides in drinking water and foodstuffs.

The main objective of the presented dissertation was to improve two important performance characteristics of methods applicable for determination of multiple residues of modern pesticides in drinking water and foods: the analysis time and the sample throughput. In gas chromatography, which is the prevailing determinative technique in pesticide multiresidue analysis, two significant trends, both potentially contributing to the increased sample throughput, can be observed. the use of gas chromatography-mass spectrometry as a primary tool for determination of analytes and attempts to increase speed of GC analysis.Available from STL, Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi

Mycotoxins in Plant-Based Dietary Supplements: Hidden Health Risk for Consumers

Mycotoxin contamination of dietary supplements represents a possible risk for human health, especially in the case of products intended for people suffering from certain health conditions. The aim of this study was to assess the extent of this problem based on analyses of a wide set of herbal-based dietary supplements intended for various purposes: (i) treatment of liver diseases (milk thistle); (ii) reduction of menopause effects (red clover, flax seed, and soy); and (iii) preparations for general health support (green barley, nettle, goji berries, yucca, etc.) The analytical method including 57 mycotoxins was based on a QuEChERS-like (quick, easy, cheap, effective, rugged, safe) approach and ultrahigh performance liquid chromatography coupled with tandem mass spectrometry. The main mycotoxins determined were <i>Fusarium</i> trichothecenes, zearalenone and enniatins, and <i>Alternaria</i> mycotoxins. Co-occurrence of enniatins, HT-2/T-2 toxins, and <i>Alternaria</i> toxins was observed in many cases. The highest mycotoxin concentrations were found in milk thistle-based supplements (up to 37 mg/kg in the sum)

Handbook of Food Analysis Instruments

This monograph published by Taylor&Francis Publishing House contains versatile instrumentation that is applied in food analysis. More than 40 authors, experts from different fields, took part in writing comprehensive chapters related to various aspects of microscopic, chromatographic, UV VIS, electrochemical, Fluorescence, Electrophoresis, AFM and IR techniques applied in food analysis. In the beginning of this book, authors provide comprehensive statistic relevant to analytical chemistry. Also, extraction and preparation methods in food analysis are extensively explained. The readers can get an insight in several free chapters of this Monograph (issued on line in 2016) available for free in 2021

Multilaboratory Collaborative Study of a Nontarget Data Acquisition for Target Analysis (nDATA) Workflow Using Liquid Chromatography-High-Resolution Accurate Mass Spectrometry for Pesticide Screening in Fruits and Vegetables

Nontarget data acquisition for target analysis (nDATA) workflows using liquid chromatography-high-resolution accurate mass (LC-HRAM) spectrometry, spectral screening software, and a compound database have generated interest because of their potential for screening of pesticides in foods. However, these procedures and particularly the instrument processing software need to be thoroughly evaluated before implementation in routine analysis. In this work, 25 laboratories participated in a collaborative study to evaluate an nDATA workflow on high moisture produce (apple, banana, broccoli, carrot, grape, lettuce, orange, potato, strawberry, and tomato). Samples were extracted in each laboratory by quick, easy, cheap, effective, rugged, and safe (QuEChERS), and data were acquired by ultrahigh-performance liquid chromatography (UHPLC) coupled to a high-resolution quadrupole Orbitrap (QOrbitrap) or quadrupole time-of-flight (QTOF) mass spectrometer operating in full-scan mass spectrometry (MS) data-independent tandem mass spectrometry (LC-FS MS/DIA MS/MS) acquisition mode. The nDATA workflow was evaluated using a restricted compound database with 51 pesticides and vendor processing software. Pesticide identifications were determined by retention time (tR, ±0.5 min relative to the reference retention times used in the compound database) and mass errors (?M) of the precursor (RTP, ?M ≤ ±5 ppm) and product ions (RTPI, ?M ≤ ±10 ppm). The elution profiles of all 51 pesticides were within ±0.5 min among 24 of the participating laboratories. Successful screening was determined by false positive and false negative rates of <5% in unfortified (pesticide-free) and fortified (10 and 100 μg/kg) produce matrices. Pesticide responses were dependent on the pesticide, matrix, and instrument. The false negative rates were 0.7 and 0.1% at 10 and 100 μg/kg, respectively, and the false positive rate was 1.1% from results of the participating LC-HRAM platforms. Further evaluation was achieved by providing produce samples spiked with pesticides at concentrations blinded to the laboratories. Twenty-two of the 25 laboratories were successful in identifying all fortified pesticides (0-7 pesticides ranging from 5 to 50 μg/kg) for each produce sample (99.7% detection rate). These studies provide convincing evidence that the nDATA comprehensive approach broadens the screening capabilities of pesticide analyses and provide a platform with the potential to be easily extended to a larger number of other chemical residues and contaminants in foods