Xiao Jin-Jing, Li Yang, Fang Qing-Kui, Shi Yan-Hong, Liao Min, Wu Xiang-Wei, Hua Ri-Mao, Cao Hai-Qun
School of Plant Protection, Anhui Agricultural University, Hefei 230036, China.
Provincial Key Laboratory for Agri-Food Safety, Anhui Agricultural University, Hefei 230036, China.
Int J Environ Res Public Health. 2017 Sep 30;14(10):1157. doi: 10.3390/ijerph14101157.
The transfer of pesticide residues from herbal teas to their infusion is a subject of particular interest. In this study, a multi-residue analytical method for the determination of pyrethroids (fenpropathrin, beta-cypermethrin, lambda-cyhalothrin, and fenvalerate) in honeysuckle, chrysanthemum, wolfberry, and licorice and their infusion samples was validated. The transfer of pyrethroid residues from tea to infusion was investigated at different water temperatures, tea/water ratios, and infusion intervals/times. The results show that low amounts (0-6.70%) of pyrethroids were transferred under the different tea brewing conditions examined, indicating that the infusion process reduced the pyrethroid content in the extracted liquid by over 90%. Similar results were obtained for the different tea varieties, and pesticides with high water solubility and low octanol-water partition coefficients (log K) exhibited high transfer rates. Moreover, the estimated values of the exposure risk to the pyrethroids were in the range of 0.0022-0.33, indicating that the daily intake of the four pyrethroid residues from herbal tea can be regarded as safe. The present results can support the identification of suitable tea brewing conditions for significantly reducing the pesticide residue levels in the infusion.
农药残留从凉茶转移至其泡出液是一个特别受关注的课题。在本研究中，一种用于测定金银花、菊花、枸杞和甘草及其泡出液样品中拟除虫菊酯类（甲氰菊酯、高效氯氰菊酯、氯氟氰菊酯和氰戊菊酯）的多残留分析方法得到了验证。研究了在不同水温、茶水比以及浸泡间隔/时间条件下拟除虫菊酯类农药残留从茶叶向泡出液的转移情况。结果表明，在所考察的不同泡茶条件下，仅有少量（0 - 6.70%）的拟除虫菊酯类被转移，这表明浸泡过程使提取液中的拟除虫菊酯类含量降低了90%以上。不同茶品种得到了类似结果，且水溶性高、正辛醇 - 水分配系数（log K）低的农药表现出较高的转移率。此外，拟除虫菊酯类的暴露风险估计值在0.0022 - 0.33范围内，这表明从凉茶中每日摄入的这四种拟除虫菊酯类残留可被视为安全的。目前的结果有助于确定能显著降低泡出液中农药残留水平的合适泡茶条件。
