Determination of pesticides in grape juices by QuEChERS and liquid chromatography-tandem mass spectrometry

Abstract

In this study, we describe a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for quantifying 25 pesticides in grape juice. This method was optimized and validated according with INMETRO (Instituto Nacional de Metrologia Qualidade e Tecnologia) for the simultaneous determination of pesticide, which are widely used in grape culture in Brazil. The method was based on the QuEChERS (quick, easy, cheap, effective, rugged and safe) methodology. We used AOAC Official Method 2007.01 and Standard Method EN 15662 for sample preparation, both methods presented statistically equivalent recoveries and coefficients of variation. At 0.005 and 2 mg L-1, fortified blank grape juices had average recoveries of 101 and 112% and average coefficients of variation of 16 and 11%, respectively. The repeatability was tested in three concentrations 0.005, 0.1 and 2 mg L-1, affording coefficients of variation 16.4, 20.7 and 10.8%, respectively.