Dynamic microwave-assisted extraction online coupled with single drop microextraction of organophosphorus pesticides in tea samples

Objective: The objective of this research was to improve the method of extracting pesticide residue from vegetable by using microwave-assisted extraction, headspace single drop microextraction (MAE-HS-SDME) and analysed by gas chromatograph-mass spectrometer (GC-MS).Methods: Microwave-assisted extraction (MAE) coupled with headspace single drop microextraction (HS-SDME) was used for extraction of chlorpyrifos insecticide residues in lettuce. The optimum conditions for obtaining efficient extraction have been tried; kind and quantity of solvent, extraction time, microwave irradiation power, pH value and the amount of salt added in the sample followed the method of Plackett–Burman. Optimum conditions for efficient analysis were evaluated by using a central composite design (CCD) combined with a response surface methodology (RSM).Results: The optimum extract conditions from CCD for the MAE-HS-SDME method were: using 1.5 µl of n-butyl acetate, 460 W of the microwave power, 4.5 min of the extraction time, no pH adjustment and no salt addition. Verification of the optimized experimental conditions showed that validation of the determination coefficient ranges from the concentrations of 0.01 to 0.10 mg/l, equal to 0.999; the percentages of variation coefficient were ranges from 4.6 to 7.7%; the recoveries ranges from 70.0 to 79.5%; limit of detection was 0.003 mg/kg and limit of quantitation was 0.01 mg/kg.Conclusion: In this study, the MAE-HS-SDME method coupled with GC-MS was found most suitable for chlorpyrifos analysis. The results obtained from analyzing chlorpyrifos in lettuce samples indicated that this method is rapid, simple, sensitive, reducible cost and safety for the analyst and the environment.

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Development of microwave-assisted extraction followed by headspace single-drop microextraction for fast determination of paeonol in traditional Chinese medicines

Journal of Chromatography A ◽

10.1016/j.chroma.2005.11.023 ◽

2006 ◽

Vol 1103 (1) ◽

pp. 15-21 ◽

Cited By ~ 93

Author(s):

Chunhui Deng ◽

Ning Yao ◽

Ben Wang ◽

Xiangmin Zhang

Keyword(s):

Traditional Chinese Medicines ◽

Microwave Assisted Extraction ◽

Single Drop ◽

Fast Determination ◽

Chinese Medicines ◽

Microwave Assisted ◽

Assisted Extraction ◽

Single Drop Microextraction

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Microwave-Assisted Extraction Coupled with Single Drop Microextraction and High-Performance Column Liquid Chromatography for the Determination of Trace Estrogen Adulterants in Soybean Isoflavone Dietary Supplements

Journal of AOAC International ◽

10.1093/jaoac/93.3.849 ◽

2010 ◽

Vol 93 (3) ◽

pp. 849-854 ◽

Cited By ~ 4

Author(s):

Xiaohua Xiao ◽

Yi Yin ◽

Yuling Hu ◽

Gongke Li

Keyword(s):

Dietary Supplements ◽

High Performance ◽

Ethinyl Estradiol ◽

Accurate Method ◽

Microwave Assisted Extraction ◽

Single Drop ◽

Microwave Assisted ◽

Assisted Extraction ◽

Single Drop Microextraction

Abstract A sensitive and accurate method consisting of microwave-assisted extraction (MAE) coupled with single drop microextraction (SDME) and HPLC was developed for the determination of four trace estrogen adulterants, including estriol (E3), estradiol (E2), ethinyl estradiol (EE), and estrone (E1), in different soybean dietary supplements. The samples were extracted by MAE; the extracts were cleaned up and enriched by SDME, and then analyzed by HPLC. The conditions of MAE were optimized, and the effects of solvent and extraction time in SDME on the enrichment capacity were studied. The enrichment factors of E3, E2, EE, and E1 under the optimized conditions were 247-, 335-, 316-, and 319-fold, respectively. The linear range of the MAE-SDME-HPLC method ranged from 5.0 to 180.0 g/L, and the detection limit from 1.1 to 1.2 g/L. The RSD ranged from 7.9 to 9.6. Three soybean dietary supplements, including oral liquid, capsule, and tablet forms, were analyzed. The spike recovery was more than 70, with RSD lower than 13.2. It was shown that the proposed method was accurate, sensitive, and suitable for the determination of trace analytes in complex samples.

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