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目的建立茶叶中高氯酸盐的同位素标记-超高效液相色谱-串联质谱测定法。方法茶叶样品经超纯水-甲醇(2∶3,V/V)提取后,高速离心,上清液用PRi ME HLB柱净化,再经Thermo Acclaim TRINITY P1色谱柱分离,串联质谱法检测,内标法定量。结果高氯酸盐在0.25μg/L~50.0μg/L时线性回归方程为y=0.329 86x+0.031 82,相关系数(r)为0.999 3。加标浓度为0.10 mg/kg、0.40 mg/kg、0.80 mg/kg时,绿茶、红茶、茉莉花茶的平均回收率分别为93.8%~103.5%、93.4%~98.6%、94.6%~102.7%,相对标准偏差(RSD)分别为2.4%~4.6%、3.6%~4.9%、3.7%~4.8%。检出限为2.0μg/kg。结论本方法前处理简单、灵敏度高、准确、可靠,适用于茶叶中高氯酸盐的测定。
Objective To establish an isotopic labeling of perchlorate in tea - Ultra Performance Liquid Chromatography - Tandem Mass Spectrometry. Methods The tea samples were extracted with ultrapure water - methanol (2: 3, V / V) and centrifuged at high speed. The supernatants were cleaned up with PRi ME HLB column, separated by Thermo Acclaim TRINITY P1 column and detected by tandem mass spectrometry Standard method of quantitative. Results The linear regression equation of perchlorate at 0.25μg / L ~ 50.0μg / L was y = 0.329 86x + 0.031 82 with a correlation coefficient (r) of 0.999 3. The average recoveries of green tea, black tea and jasmine tea were 93.8% ~ 103.5%, 93.4% ~ 98.6% and 94.6% ~ 102.7% at the spiked concentrations of 0.10 mg / kg, 0.40 mg / kg and 0.80 mg / The relative standard deviations (RSDs) were 2.4% -4.6%, 3.6% -4.9% and 3.7% -4.8%, respectively. The detection limit was 2.0μg / kg. Conclusion The method pretreatment is simple, sensitive, accurate and reliable, suitable for the determination of perchlorate in tea.