Determination of multi-class herbicides in soil by liquid-solid extraction coupled with headspace solid phase microextraction method

A method is described for simultaneous determination of five herbicides (metribuzin, acetochlor, clomazone, oxyfluorfen and dimethenamid) belonging to different pesticides groups in soil samples. Developed headspace solid phase microextraction method (HS-SPME) in combination with liquid-solid sample preparation (LS) was optimized and applied in the analysis of some agricultural samples. Optimization of microextraction conditions, such as temperature, extraction time and sodium chloride (NaCl) content was perfor-med using 100 ?m polydimethyl-siloxane (PDMS) fiber. The extraction effi-ciencies of methanol, methanol:acetone=1:1 and methanol:acetone:hexane= =2:2:1 and the optimum number of extraction steps during the sample prepa-ration, were tested, as well. Gas chromatography-mass spectrometry (GC-MS) was used for detection and quantification, obtaining relative standard deviation (RSD) below 13%, and recovery values higher than 83% for multiple analyses of soil samples fortified at 30 ?g kg-1 of each herbicide. Limits of detection (LOD) were less than 1.2 ?g kg-1 for all the studied herbicides.

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Determination of atrazine, acetochlor, clomazone, pendimethalin and oxyfluorfen in soil by a solid phase microextraction method

Pesticidi i fitomedicina ◽

10.2298/pif0804265d ◽

2008 ◽

Vol 23 (4) ◽

pp. 265-271 ◽

Cited By ~ 7

Author(s):

Rada Djurovic ◽

Jelena Gajic-Umiljendic ◽

Tijana Djordjevic

Keyword(s):

Sample Preparation ◽

Solid Phase Microextraction ◽

Solid Phase ◽

Soil Samples ◽

Extraction Time ◽

Gas Chromatography Mass Spectrometry ◽

Optimum Number ◽

Extraction Solvent ◽

Relative Standard

A solid phase microextraction (SPME) method for simultaneous determination of atrazine, acetochlor, clomazone, pendimethalin and oxyfluorfen in soil samples was developed. The method is based on a combination of conventional liquid-solid procedure and a following SPME determination of the selected pesticides. Initially, various microextraction conditions, such as the fibre type, desorption temperature and time, extraction time and NaCl content, were investigated and optimized. Then, extraction efficiencies of several solvents (water, hexane, acetonitrile, acetone and methanol) and the optimum number of extraction steps within the sample preparation step were optimized. According to the results obtained in these two sets of experiments, two successive extractions with methanol as the extraction solvent were the optimal sample preparation procedure, while the following conditions were found to be most efficient for SPME measurements: 100 ?m PDMS fibre, desorption for 7 min at 2700C, 30 min extraction time and 5% NaCl content (w/v). Detection and quantification were done by gas chromatography-mass spectrometry (GC/MS). Relative standard deviation (RSD) values for multiple analysis of soil samples fortified at 30 ?g/kg of each pesticide were below 19%. Limits of detection (LOD) for all the compounds studied were less than 2 ?g/kg.

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Liquid–Solid Sample Preparation Followed by Headspace Solid-Phase Microextraction Determination of Multiclass Pesticides in Soil

Journal of AOAC International ◽

10.5740/jaoacint.sge_durovic ◽

2012 ◽

Vol 95 (5) ◽

pp. 1331-1337 ◽

Cited By ~ 7

Author(s):

Rada D Ðurović ◽

Tijana M Ðorðević ◽

Ljiljana R Šantrić

Keyword(s):

Sample Preparation ◽

Solid Phase Microextraction ◽

Solid Phase ◽

Extraction Procedure ◽

Soil Samples ◽

Optimum Number ◽

Headspace Solid Phase Microextraction ◽

Extraction Solvents ◽

Development And Validation

Abstract This paper describes development and validation of a multiresidue method for the determination of five pesticides (terbufos, prochloraz, chloridazon, pendimethalin, and fluorochloridone) belonging to different pesticide groups in soil samples by GC/MS, followed by its application in the analysis of some agricultural soil samples. The method is based on a headspace solid-phase microextraction method. Microextraction conditions, namely temperature, extraction time, and NaCl content, were tested and optimized using a 100 μm polydimethylsiloxane fiber. Three extraction solvents [methanol, methanol–acetone (1 + 1, v/v), and methanol–acetone–hexane (2 + 2 + 1, v/v/v)] and the optimum number of extraction steps within the sample preparation stage were optimized for the extraction procedure. LOD values for all the studied compounds were less than 12 μg/kg. Recovery values for multiple analyses of soil samples fortified at 30 μg/kg of each pesticide were higher than 64%. The method was proven to be repeatable, with RSD lower than 15%.

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