关键词: 净化, 竹笋, 农药残留

Abstract: An analytical method was developed for the determination of 21 pesticide residues in bamboo shoot using dispersive solid phase extraction clean-up combined with gas chromatography (GC). To optimize this method, we compared the effects of different adsorbents on the purification of bamboo shoot extract and clean-up and the?baseline?of electron capture detector (ECD). Bamboo shoot samples were extracted with acetonitrile, followed by clean-up by dispersive solid phase extraction with anhydrous MgSO4, Florisil, primary secondary amine (PSA), strong cation exchange (SCX) or Pesticarb and subsequent determination by GC-ECD. All the 21 pesticides could be completely separated with an excellent linear relationship. The limits of detection (LODs) and quantification (LOQs) for the 21 pesticides were in the range of 0.079–1.77 and 0.26–5.89 μg/kg, respectively. For all spiked samples, mean recoveries were 92.97% with relative standard deviations (RSDs, n = 3) of less than 6.07%. The presented method was successfully applied to analyze 230 samples from China’s main bamboo shoot-producing regions. Apart?from fenvalerate, all the pesticides were detected from the 230 samples. p,p’-DDE (33.48%), δ-BHC (26.52%) and cyhalothrin (26.09%) showed high detection rates. Buprofezin was detected in the highest concentration of 9 508.9 μg/kg, which showed the largest percentage increase (6.69%) compared to the maximum residue limit.

Key words: clean-up, bamboo shoot, pesticide residues