苯醚甲环唑在茶叶中的残留量及其在茶汤中的浸出动态研究

采用气相色谱-电子捕获检测器(GC-ECD)对田间采集的茶叶样品中的苯醚甲环唑残留量进行了测定,同时对泡茶后茶汤中苯醚甲环唑的浸出动态进行了研究。结果表明:苯醚甲环唑10%水分散粒剂分别按有效成分100和150 mg/kg于茶叶炭疽病发生初期施药2~3次,距末次施药后间隔5 d采样,成茶中苯醚甲环唑的残留量低于最大残留限量(MRL)值10.0 mg/kg;茶汤中苯醚甲环唑残留量及浸出率随冲泡次数的增加逐渐下降,4次冲泡的总浸出率为19.6% ~21.8%,人体摄入的苯醚甲环唑残留量占每日允许摄入量(ADI)的9.0%。

Study on residue of difenoconazole in tea and its transfer from made tea to infusion

A field experiment was conducted to reveal residue of difenoconazole in made tea,determined by gas chromatography(GC-ECD).Furthermore,the dissolution dynamic of difenoconazole from tea infusion were studied.Results showed that when the tea was sprayed 2 to 3 times with 100 and 150 a.i.mg/kg difenoconazole 10% WG at the initial stage of anthracnose of tea,with pre-harvest intervals (PHI) of 5 d,residue of difenoconazole in made tea was lower than 10.0 mg/kg(MRL proposed).The dissolution ratio was declined with the increasing of dunking number.Theres low level of difenoconazole residue in the infusion of tea,with only 19.6% to 21.8% was entered the infusion after 4 total times.The estimated intake of difenoconazole is shown to be 9.0 percentage of Accepatbable Daily Intake (ADI).