An analytical method was developed by using LC-ESI(−ve)-MS/MS to investigate the residue dynamics of 2,4-D (2,4-dichlorophenoxyacetic acid) in green tea leaves, processed tea, tea liquor, and tea-cropped soil at Singhiajhora Tea Estate and Putinbari Tea Estate at Terai Region, Darjeeling District, West Bengal, India. In this method, an acidified methanol was used for extraction and subsequent clean-up was done by HLB (hydrophilic lipophilic balanced) cartridges. The method was validated as per SANTE guideline (SANTE/11813/2017). The limit of quantification (LOQ) of 2,4-D was 0.05 mgkg⁻¹ and average % recoveries were in the range from 88.05 to 113.28 with relative standard deviation (RSD) 3.46 to 6.43. The dissipation of 2,4-D followed the 1st-order reaction kinetics with a half-life (T_1/2) of 1.51–1.61 day at the recommended dose and 2.50–2.72 day for doubled recommended dose in tea for both locations. This method can be applied successfully for the determination of 2,4 D residues in/on tea matrix and subsequent studies on safety evaluation showed that the use of 2,4-D in tea is safe.

通过使用LC-ESI（-ve）-MS / MS开发了一种分析方法，以研究绿茶叶，加工茶，茶液和茶中2,4-D（2,4-二氯苯氧乙酸）的残留动力学印度西孟加拉邦大吉岭区Terai地区的Singhiajhora茶园和Putinbari茶园种植的土壤。在这种方法中，使用酸化的甲醇进行萃取，随后通过HLB（亲水性亲脂平衡）滤芯进行净化。该方法已根据SANTE指南（SANTE / 11813/2017）进行了验证。2,4-D的定量极限（LOQ）为0.05 mgkg ^-1，平均回收率在88.05至113.28之间，相对标准偏差（RSD）为3.46至6.43。2,4-D的消散遵循一阶反应动力学，具有半衰期（T推荐剂量的1.51–1.61天的_1/2）和两个位置的茶中推荐剂量的两倍的2.50–2.72天。该方法可成功用于茶叶基质中/茶叶中2,4 D残留的测定，随后的安全性评估研究表明，在茶叶中使用2,4-D是安全的。