Pesticide enrichment factors and matrix effects on the determination of multiclass pesticides in tomato samples by single-drop microextraction (SDME) coupled with gas chromatography and comparison study between SDME and acetone-partition extraction procedure

This study describes an analytical method employing capillary gas chromatography (GC) using flame ionization detection (FID) that has been developed for the simultaneous determination of chlorobenzenes (m-dichlorobenzene (m-DCB),p-dichlorobenzene (p-DCB),o-dichlorobenzene (o-DCB) and 1,2,4-trichlorobenzene (1,2,4-TCB)) in wastewater. For this purpose, single-drop microextraction (SDME) was applied as a sample preparation technique. The SDME parameters such as types of extractants, volume of the microdroplet size, extraction time, stir rate and immersion depth of needle point were studyed and optimized. The method was linear in the ranges from 4.0×10-3to 40.0 μg·mL-1form-DCB,p-DCB ando-DCB, and 4.0×10-3to 30.0 μg·mL-1for 1,2,4-TCB withR2≥0.9955. The SDME procedure allowed efficient recovery of the investigated chlorobenzenes ranging between 80 % and 105 % with a relative standard deviation (RSD) ≤6.5 for actual wastewater sampes spiked with 2, 5 and 10 μg·mL-1of chlorobenzes, respectively. These results showed the potential of this technique for chlorobenzenes monitoring in wastewater samples. Furthermore, the investigated methods are simple, reliable, reproducible, and not expensive.

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Determination of Pesticide Residues in Honey by Single-Drop Microextraction and Gas Chromatography

Journal of AOAC International ◽

10.1093/jaoac/94.2.634 ◽

2011 ◽

Vol 94 (2) ◽

pp. 634-644 ◽

Cited By ~ 15

Author(s):

Nikolaos G Tsiropoulos ◽

Elpiniki G Amvrazi

Keyword(s):

Pesticide Residues ◽

Enrichment Factors ◽

The European Union ◽

Maximum Residue Limit ◽

Single Drop ◽

Limit Values ◽

Screening Design ◽

Single Drop Microextraction ◽

Central Composite

Abstract A novel, simple, and rapid single-drop microextraction (SDME) procedure combined with GC has been developed, validated, and applied for the determination of multiclass pesticide residues in honey samples. The SDME was optimized using a Plackett-Burman screening design considering all parameters that may influence an SDME procedure and a consequent central composite design to control the parameters that were found to significantly influence the pesticide determination. The developed analytical method required minimal volumes of organic solvents and exhibited good analytical characteristics with enrichment factors ranging from 3 for -endosulfan to 10 for lindane, procymidone, and captan and method quantification limits ranging from 0.03 g/kg for phosalone to 10.6 g/kg for diazinon. The relative recoveries obtained ranged from 70.8 for captan to 120 for fenarimol, and the precision (RSD) ranged from 3 to 15. The proposed SDME procedure followed by GC with an electron capture detector for quantification and GC/MS for identification was applied with success to the analysis of 17 honey samples. Monitoring results indicated a low level of honey contamination by diazinon, chlorpyrifosethyl, procymidone, bromopropylate, and endosulfan (-, -, and endosulfan sulfate) residues that were far below the maximum residue limit values specified by the European Union for endosulfan (10 g/kg) and bromopropylate (100 g/kg) in honey samples.

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Determination of Volatile Halogenated Hydrocarbons in Wastewater by Single-Drop Microextraction Coupled to Capillary Gas Chromatography

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.295-298.487 ◽

2013 ◽

Vol 295-298 ◽

pp. 487-491

Author(s):

Jian Qi Sun

Keyword(s):

Gas Chromatography ◽

Capillary Gas Chromatography ◽

Halogenated Hydrocarbons ◽

Wastewater Sample ◽

Single Drop ◽

Single Drop Microextraction ◽

Relative Standard ◽

Wastewater Samples ◽

Volatile Halogenated Hydrocarbons

Single-drop microextraction (SDME) coupled to capillary gas chromatography (GC) was established for the determination of seven volatile halogenated hydrocarbons in wastewater, including chloroform (CF), carbon tetrachloride (CT), trichloroethylene (TCE), bromodichloromethane (BDCM), perchlorethylene (PCE), dibromochloromethane (DBCM) and bromoform (BF). The SDME parameters such as extractants, extracting time，stirring rate and immerging depth of needle point were studyed and optimized. The abovementioned halogenated hydrocarbons were quantified by external standardization method using GC coupled with a flame ionization detector (FID). The linear regression calibration curves, detection limits (S/N=3) and the linear ranges of the method for determining each halogenated hydrocarbons were determined, respectively. The concentrations of componds abovementioned in a real wastewater sample, the average of the recoveries obtained in the spiked wastewater samples and the corresponding relative standard deviations were determined, respectively. The results showed the proposed method several attributes, friendly enviroment, economic and highly efficient pretreatment, less time, simplicity, sensitivity, accuracy and wide linear range and so on.

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