Determination of simazine and cymoxanil in soils by microwave-assisted solvent extraction and HPLC with reductive amperometrical detection

Abstract

SummaryA microwave-assisted extraction (MAE) method was optimized for the herbicide simazine and the fungicide cymoxanil in soil samples. The experimental variables that affect MAE, such as temperature, extraction time and solvent volume, were studied. It was concluded that these pesticides could be efficiently extracted from soil samples in a microwave oven with 10 mL of acetonitrile at 90 ~ for 5 min The analysis of extracts has been carried out by high performance liquid chromatography with amperometric reductive detection (HPLC-ED). The detector, equipped with a hanging mercury drop electrode (HMDE), operated in direct current mode at-1.2 Vvs Ag/AgCI, when a mobile phase consisting of phosphate buffer-acetonitrile (95:5, v/v) was used. The procedure developed involving MAE and HPLC-ED provided detectability in soil samples of 30 I~g Kg 1, acceptable recoveries (range 82.3-100.3%) and RSDs of lower than 5% for cymoxanil and simazine.

Modern Methods of Sample Preparation for GC Analysis

“…Applications PAHs, PCBs, phthalate esters and pesticides are prominent classes of target analytes and sample types include soils [50,51], sediments [52] and various types of biological matrices [53,54]. Relevant information on a selected number of recent MAE-based applications is presented in Table 3.…”

Simultaneous microextraction of pesticides from wastewater using optimized μSPEed and μQuEChERS techniques for food contamination analysis

“…Fungicides are another group of pesticides widely used for different purposes, namely, to kill fungus parasites that colonize crop species. This is the case with thiabendazole (THIA, 4-(1H-benzimidazol-2-yl)-1,3-thiazole), a post-harvesting pesticide used to preserve citrus fruits during transport and storage [ 17 ] and cymoxanil (CYM, (1E)-2-(ethylcarbamoylamino)-N-methoxy-2-oxoethanimidoyl cyanide) used against grape downy mildew [ 18 ]. Table 1 aggregates relevant information on selected pesticides, their classification, toxicity and authorized maximum residue levels (MRLs) in foodstuffs according to the legislation adopted by the European Union [ 19 ].…”

Parameters Affecting Extraction of Selected Fungicides from Vineyard Soils

“…In previous methods for the determination of fungicides or pesticides in soil, the analyte has been extracted from the sample in a Soxhlet or by means of microwaves, shaking, or sonication, using organic solvents or solvent mixtures: acetone (4,12,13), acetonitrile (1,14,15), benzene (2), cyclohexane (5), ethyl acetate (7), methanol (16)(17)(18)(19), acetonitrile plus water (20), ethyl acetate plus acetone (21), or methanol plus water (3,6,(22)(23)(24). The method described in this paper also uses an organic extractant (ethyl acetate), but, unlike many of the methods cited above, it does not require subsequent partition or chromatographic purification steps, which significantly lengthen the procedures in which they are employed.…”