Analysis of Organophosphorus Pesticides by Solid Phase Extraction Using Multi-walled Carbon Nanotubes as Adsorbent

作者：Zhao Hai Xiang; Shi Wen Li; Sun Da Jiang; Wang Hua; Zhang Lian Peng; Zao Meng Bin; Ding Ming Yu^*

来源：Chinese Journal of Analytical Chemistry, 2009, 37(10): 1479-1483.

• Multi-walled carbon nanotubes
• solid phase extraction
• organophosphorus pesticides
• vegetables
• gas chromatography-flame photometric detector

A multi-residue analytical method based on solid phase extraction with multi-walled carbon nanotubes(MWCNTs) as adsorbent was developed. The determination of 16 organophosphorus pesticides(methamidaphos, mevinphos, phorate, diazinon, monocrotophos, dimethoate, chlorpyrifos-methyl, pirimiphos-methyl ester, chlorpyrifos, fenthion, isocarbophos, quintiofos, Methidathion, ethion, phosalone, phthalophos) in vegetables(including cucumber, grape tomato, cabbage, leek, ginger and onion) was carried out by gas chromatography-flame photometric detector (GC/FPD). Two columns (HP-50 for the analysis and HP-1 for the validation) and two FPD detectors were used in this method. The clean-up conditions that included pretreatment of MWCNTs SPE, re-dissolved solvent, and eluted solvent were optimized. The experimental results showed the MWCNTs SPE cartridge can adsorb the coloring background and the eluent was colorless. Two clean-up methods were developed. For the water phase clean-up method, the extracts were re-dissolved by 5 ml, pH 5.0 HAc-NaAc buffer, dried 10 min under vacuum, the analyte were eluted by 10 mL dichlorme-thane, the recoveries of 9 organophosphorus pesticides were over 75%, and RSD were under 9%. For the organic phase clean-up method, the extracts were re-dissolved in 2 ml, hexane, and then eluted with acetone-hexane(5:5, V/V). The recoveries were over 75% and RSD were under 11.7% for 16 organophosphorus pesticides. This study indicated the MWCNTs SPE cartridge was efficient clean-up method to vegetable(included sulfur-containing Vegetables) because it reduced the contamination of the coloring background to GC/FPD.

• 出版日期2009-10
• 单位清华大学; 河北北方学院