联苯菊酯等菊酯类农药在茶叶上使用安全性研究

Application of bifenthrin and other pyrethroids in tea fields

不规范使用农药,容易造成茶叶中农药残留,危害茶园环境,影响消费者健康。联苯菊酯是茶园中较为常用的农药。有研究表明,菊酯类农药在茶树上降解量的约45%是由生长稀释引起的。按照推荐浓度施用,7天安全间隔期后残留量可以降低至安全限量(5 mg/kg)以下。加工过程中联苯菊酯降低24%左右,主要发生在干燥工序。茶叶中的菊酯类农药在茶汤中浸出较少,绿茶和红碎茶中联苯菊酯在冲泡中分别溶出4.4%和4.6%。通过田间喷施降解剂(包括微生物制剂、氧化剂等)、辐照处理干茶等也有进一步降解联苯菊酯残留的效果。

Bifenthrin is widely used in tea fields safety of bifenthrin and other synthetic pyrethroids in The present paper reviews the application and tea production. The synthetic pyrethroids were degraded on tea plants, in which about 45% of the degradation was caused by growth dilution. The residue of bifenthrin and pyrethroids would be decreased to maximum residue limit （5 mg/kg） after 7-day safety interval period if they were used at the recommended concentration. During tea processing, about 24% of bifenthrin remained in tea leaves was further degraded, in which most of them took placed in the dry process. During tea brewing, the extraction rate of bifenthrin residue in tea leaves was 4.4% for green tea and 4.58% for black tea respectively. The residues of bifenthrin and other synthetic pyrethroids were partially degraded by spraying degradation agents in tea fields （such as microbial agents or oxidants） or exposing the tea to various radiations such as gamma ray.