Multianalyte, high-throughput liquid chromatography tandem mass spectrometry method for the sensitive determination of fungicides and insecticides in wine

Abstract

Evidence of pesticide transfer from grapes to wine, added to differences in the national regulations regarding the number and the maximum concentration of these species in wine, demands analytical procedures suitable for their routine control in this foodstuff. In this research, solid-phase extraction (SPE) and ultra-performance liquid chromatography (UPLC), with tandem mass spectrometry (MS/MS) detection, are combined to obtain a sensitive and rapid procedure to determine 50 pesticides in red and white wines. Efficiency and selectivity of sample preparation are correlated with the type of sorbent, the elution solvent, and the physicochemical properties of pesticides. SPE of 2-mL wine samples followed by direct injection of the extract in the UPLC-MS/MS system provides quantification limits (LOQs) below 1 ng mL for 48 out of 50 compounds, linear responses up to 200 ng mL, and acceptable accuracy, employing quantification against solvent-based standards, for 45 species. A total analysis time of 10 min, including compounds separation and re-equilibration of the UPLC column, was achieved. The developed methodology was applied to 25 wines (20 conventional and 5 ecological), produced in 7 different countries. Out of 27 pesticides quantified in these wines, 12 displayed occurrence frequencies above 24%; moreover, all wines, except one of the ecological ones, contained residues from at least one pesticide.

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

“…For the rest of compounds, LOQs remain three orders of magnitude below MRLs for grapes. When compared with values achieved in previous studies, the LOQs compiled in Table 3 are significant lower than those reported for SPE techniques (from 0.1 to 15 ng mL -1 , depending on the compound) [9,10] and also than those reported for QuEChERS (ca.…”

“…The relative deviations of retention times through a typical sequence, involving more than 50 injections, remained below 0.15% for all the compounds. Additional instrumental parameters, including ESI variables were adopted from a previous study [10].…”

“…SPE was used as a reference technique to evaluate the absolute extraction efficiency (EE) of the optimized FPSE method under equilibrium sampling conditions. To this end, 4 mL of the diluted wine solution, previously exposed to the FPSE sorbent, were concentrated by SPE under reported elsewhere [10]. Aliquots (4 mL) of the same spiked solution, not submitted to FPSE, were also concentrated by SPE.…”

“…Subsequently, FPSE sorbent pieces were desorbed with 1 mL of ACN: MeOH (80:20) solution. This mix of solvents has been recommended for the quantitative extraction of fungicides and insecticides from reversed-phase SPE cartridges [10], whilst many of the red wine pigments remained attached to the SPE sorbent.…”

“…Although some studies describe wine analysis by direct injection of the filtered sample in the chromatographic system [4,5], a sample preparation step is usually required to remove unwanted components, to increase the concentration of pesticides and/or to make the wine matrix compatible with the chromatographic instrument (in case of gas chromatography (GC) based methods). Solid-phase extraction (SPE) [6][7][8][9][10] and QuEChERS [11][12][13][14] are the most common sample preparation methodologies to extract and/or to concentrate multiclass pesticides from wine. Despite the widespread use of the above techniques in food control laboratories, there is an increasing concern about the voluminous consumption of organic solvents during sample preparation, a trend to move towards the so-called Green Analytical Chemistry (GAC) supported extraction methodologies; and also a continuous search to reduce resources dedicated to sample preparation.…”