气相色谱-串联质谱法考察茶汤中49种农药的迁移规律

Investigation of Migration Regularity of 49 Pesticides in Tea Infusion by GC-MS/MS

采用气相色谱-串联质谱法测定茶叶浸泡茶汤中49种农药含量,通过公式计算农药的迁移率,考察农药的迁移率与农药的溶解度、迁移率与其在正辛醇-水中的分配系数(logKow)之间的关系。结果表明:茶叶浸泡后农药迁移率范围,第一汤在82.4%以内,第二汤在16.1%以内,第一汤中农药的迁移率较高;茶汤中农药的总迁移率与其在水中的溶解度呈正相关(Pearson相关系数为0.743;P<0.01),差异有统计学意义;与农药在辛醇-水中的分配系数呈负相关(Pearson相关系数为-0.984;P<0.01),差异有统计学意义。因此,茶叶浸泡后第一汤中农药迁移率较高,饮茶时建议弃掉第一汤,以减少茶汤引起的农药暴露;种植茶叶过程中推荐使用水中溶解度低且分配系数较高的农药。

The 49 pesticides in tea infusion were determined by GC-MS/MS,then values of migration rate of pesticides were calculated by formula.Relationships between migration rate and solubility of pesticides,and between migration rate of pesticides and distribution coefficient(LogKow)in n-octyl alcohol-water was studied.The results showed that the range of migration rate of pesticides after tea soaking:the first soup was within 82.4%,the second soup was within 16.1%,and the migration rate of pesticides in the first soup was relatively high.The total migration rate of pesticides in tea soup was positively correlated with solubility in water(Pearson correlation coefficient was 0.743,P<0.01),the difference was statistically significant;and the total migration rate of pesticides in tea soup was negatively correlated with distribution coefficient in n-octyl alcohol-water(Pearson correlation coefficient was-0.984,P<0.01);the difference was statistically significant.Therefore,the migration rate of pesticides in the first soup after tea soaking was relatively high,so it was suggested to drop the first soup when drinking tea to reduce the pesticide exposure caused by tea infusion.Pesticides with low solubility in water and high distribution coefficient were recommended for tea planting.