【摘要】 建立了在番茄及土壤中乙烯利的顶空-气相色谱检测方法,并研究了其在番茄和土壤中的消解动态及最终残留。利用乙烯利在碱性水溶液中受热并快速分解成乙烯的特点,结合气相色谱-氢火焰离子化检测器(GC-FID)检测。结果表明,在0.025,0.05和2.0 mg/kg三个添加水平下,乙烯利在番茄和土壤中的平均回收率在93.0%~109.1%之间,相对标准偏差(RSD)为0.7%~5.0%。乙烯利在三地番茄及土壤中的消解半衰期分别为5.9~8.2 d和1.3~4.5 d,表明乙烯利消解速率较快;采用85%乙烯利可溶性粉剂,分别按低剂量1 700倍稀释液和高剂量1 133倍稀释液于番茄果实生长至1/3时各施药1次,在收获期时乙烯利在番茄中残留量的最大值为0.682 mg/kg,低于我国制定的乙烯利在番茄中的最大残留限量标准(2 mg/kg)。更多还原

【Abstract】 A headspace-gas chromatography(HS-GC) method was developed for determining ethephon residues in tomato and soil. The dissipation curve and final residues of ethephon in tomato field were studied. The method developed was based on the special property that ethephon could be easily decomposed into ethene in alkaline solution by heating, and detected by the HS-GC-FID method. The fortified recoveries ranged from 93.0% to 109.1% with relative standard deviations of 0.7%~5.0% in tomato and soil when ethephon was spiked at 0.025, 0.05 and 2.0 mg/kg levels. The results of dissipation dynamics indicated that the half-lives of ethephon in tomato and soil were 5.9~8.2 d and 1.3~4.5 d, respectively. The tomato was sprayed with 85% soluble powder(SP) with two dosage levels, 1∶1 700 dilutions(low concentration) and 1∶1 133 dilutions(high concentration) at young tomato period. The highest residue of ethephon was 0.682 mg/kg in tomato at harvest time, and below the maximum residue limit set by China(2 mg/kg).更多还原