Chinese Journal of Chromatography

Chinese Journal of Chromatography ›› 2017, Vol. 35 ›› Issue (11): 1177-1183.DOI: 10.3724/SP.J.1123.2017.07011

Previous Articles     Next Articles

Determination of three organotin pesticide residues in apples and cabbages by gas chromatography-electron impact/positive chemical ionization mass spectrometry

CAI Lisheng1,2, SHEN Weijian2, WANG Zhengping1, ZHANG Rui2, DING Tao2, YU Keyao2, WANG Hong2, ZHANG Wenjun2, GONG Yuxia2   

  1. 1. Nanjing University of Science and Technology, Nanjing 210094, China;
    2. Jiangsu Entry-Exit Inspection and Quarantine Bureau, Nanjing 210001, China
  • Received:2017-07-13 Online:2017-11-08 Published:2014-01-17
  • Supported by:

    Shanghai Yangtze River Delta Science and Technology Cooperation Project (No. 15395810100).

PDF

101

Abstract:

A method for the simultaneous determination of fenbutatin oxide, triphenyltin and cyhexatin in apples and cabbages was developed by gas chromatography-mass spectrometry coupled with two different ionization techniques, electron impact (EI) ionization and positive chemical ionization (PCI). At first, the samples were digested by hydrobromic acid, and extracted by acetone-hexane (1:2, v/v). The extracts were derivatized by sodium tetraethylborate as the derivatization reagent, and cleaned up by the Florisil SPE columns. Finally, the samples were analyzed by GC-EI/MS and GC-PCI/MS in selected ion monitoring (SIM) mode. The results showed that good linearities were obtained with correlation coefficients (r2) greater than 0.997 for fenbutatin oxide in the range of 75-500 μg/L in both foods, triphenyltin in the range of 50-1000 μg/L in cabbages and 50-500 μg/L in apples and cyhexatin in the range of 50-1000 μg/L in the two foods. The accuracy was checked at three spiked levels (50, 100 and 200 μg/kg) in cabbages and apples. The limits of detection (LODs, S/N=3) were 0.01-0.05 mg/kg (EI) and 0.01-0.02 mg/kg (PCI), and the limits of quantifications (LOQs, S/N=10) were 0.03-0.16 mg/kg (EI) and 0.02-0.06 mg/kg (PCI). The average recoveries ranged from 59.24%-97.36% (apples) and 50.54%-94.54% (cabbages) in the mode of EI, and the corresponding values were 65.38%-95.86% and 62.56%-90.44% in the mode of PCI. The relative standard deviations (RSDs) were all less than 6.9% (n=6). The PCI method can be used to improve the accuracy in comparing with the EI, in terms of good selectivity and high sensitivity.

Key words: cyhexatin, electron impact ionization (EI), fentutatin oxide, gas chromatography-mass spectrometry (GC-MS), positive chemical ionization (PCI), triphenyltin

CLC Number: