三乙膦酸鋁在煙葉及土壤中的降解規(guī)律研究
Degradation of Phosethy-Al in Tobacco Leaves and Soils
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摘要: 煙葉及土壤中殘留的農(nóng)藥三乙膦酸鋁，經(jīng)堿解生成乙醇?xì)怏w,，以叔丁醇做內(nèi)標(biāo),，頂空進(jìn)樣，氣相色譜(FID)測(cè)定乙醇含量,，據(jù)三乙膦酸鋁對(duì)乙醇的轉(zhuǎn)化率,，推知三乙膦酸鋁殘留量。結(jié)果表明,，三乙膦酸鋁在煙葉和土壤中平均添加回收率超過84.0%,，相對(duì)標(biāo)準(zhǔn)偏差小于8.50%，方法最低檢出濃度鮮煙葉和土壤中0.01 mg/kg,，干煙葉中0.05 mg/kg,；在煙葉中消解速率較快，半衰期2.44～3.14 d,，在土壤中消解速率相對(duì)較慢,，半衰期6.20～8.98 d；最后一次施藥后21 d,，三乙膦酸鋁最終殘留量在煙葉中低于0.68 mg/kg,，在土壤中低于0.31 mg/kg。方法靈敏度和添加回收率符合農(nóng)藥殘留分析要求,。Abstract: Phosethy-Al residues in tobacco leaves and soils were analyzed by Gas Chromatography (FID). In this method residues of phosethy-Al transformed into ethanol gas in alkali liquid, the content of ethanol in FID was determined with tert-butyl alcohol as inner demarcate, then the content of phosethy-Al was calculated according to the content of ethanol. Results showed that the fortified recovery in leaves and soils was above 84.0% and relative standard deviation was under 8.50%. The minimum residue in fresh leaves, soils and dry leaves were 0.01, 0.01 and 0.05 mg/kg, respectively. The half life in leaves and soils ranged in 2.44-3.14 days and 6.20-8.98 days, respectively. The ultimate residue in leaves was lower than 0.68 mg/kg, and in soils was lower than 0.31 mg/kg, which could fulfill the residue analysis requirement.
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