Multiclass Analytical Method for Pesticide and Mycotoxin Analysis in Malt, Brewers' Spent Grain, and Beer: Development, Validation, and Application.

A multiclass analytical method to determine pesticides and mycotoxins in beer-related matrices based on the dilute and shoot approach was optimized and validated according to the European guidelines SANTE/12682/2019 and EC/401/2006. Extraction used acidified acetonitrile at 1% (v/v) acetic acid, followed by horizontal shaking homogenization, centrifugation, freeze-out step for cleanup, another centrifugation, and injection into a high-performance liquid chromatography-tandem mass spectrometry system. Linearity, detection and quantification limits, accuracy, and measurement uncertainty were evaluated, and 201, 184, and 176 analytes were validated for malt, beer, and brewers' spent grain, respectively. The limits of quantification ranged between 1 and 200 µg kg-1 and between 5 and 1000 µg kg-1 for beer and malt, respectively, and expanded uncertainties ranged between 9.7 and 50%, meeting the legislation requirements. A total of 40 samples have been analyzed thus far, and 36 of them exhibited the presence of some of the analyzed substances. The validated method is reliable and easy to apply for mycotoxin and pesticide determination in complex matrices.

Development and validation of a multianalyte method for quantification of mycotoxins and pesticides in rice using a simple dilute and shoot procedure and UHPLC-MS/MS.

In the present manuscript an analytical methodology for the simultaneous determination of ten mycotoxins and six pesticides in rice was developed. This methodology comprises the application of the dilute and shoot protocol followed by quantification via UHPLC-MS/MS. The methodology was validated and all figures of merit shown to be within the limits established by regulation. Hence, the recoveries for mycotoxins and pesticides were within the specified ranges. Precision was assessed by repeatability and intra-laboratory reproducibility with standard deviations smaller than or equal to 20%. The limits of detection, quantification and decision as well as the detection capacity were determined by the analytical curves whereas the measurement uncertainty was established by applying the bottom-up approach. Finally, the current methodology was applied to samples of rice (n = 42) commercialized in Brazil and positive results were found in only two for deoxynivalenol and zearalenone.

Simultaneous determination of fumonisins B1 and B2 in different types of maize by matrix solid phase dispersion and HPLC-MS/MS.

This work involved the optimization and validation of a method, according to Directive 2002/657/EC and the Analytical Quality Assurance Manual of Ministério da Agricultura, Pecuária e Abastecimento, Brazil, for simultaneous extraction and determination of fumonisins B1 and B2 in maize. The extraction procedure was based on a matrix solid phase dispersion approach, the optimization of which employed a sequence of different factorial designs. A liquid chromatography-tandem mass spectrometry method was developed for determining these analytes using the selected reaction monitoring mode. The optimized method employed only 1g of silica gel for dispersion and elution with 70% ammonium formate aqueous buffer (50mmolL-1, pH 9), representing a simple, cheap and chemically friendly sample preparation method. Trueness (recoveries: 86-106%), precision (RSD ≤19%), decision limits, detection capabilities and measurement uncertainties were calculated for the validated method. The method scope was expanded to popcorn kernels, white maize kernels and yellow maize grits.

Electrical field assisted matrix solid phase dispersion as a powerful tool to improve the extraction efficiency and clean-up of fluoroquinolones in bovine milk.

This work presents a new method by electrical matrix solid phase dispersion for the extraction and clean-up of marbofloxacin, ofloxacin, norfloxacin, ciprofloxacin, enrofloxacin, difloxacin and sarafloxacin in bovine milk. Composition and pH of the eluent, applied electrical potential and polarity were optimized by experimental designs. The combination of the chromatographic and electrophoretic mechanisms allowed the extraction and clean-up in one step with low organic solvent consumption, high extraction throughput and elution automation. Linearity, precision, trueness and limit of quantification were evaluated and provided values in accordance with other methods recently developed for the analysis of fluoroquinolones in milk. This technique proved to be promising for the extraction and clean-up of ionizable analytes in different milk matrices.