超声提取-液相色谱-电感耦合等离子体质谱法测定茶叶中6种砷形态的含量  

Analysis of six arsenic speciations in tea by ultrasound extraction-high-performance liquid chromatographyinductively coupled plasma mass spectrometry

作　　者：马真真 田欢 郑洪涛 Ma Zhenzhen;Tian Huan;Zheng Hongtao(Faculty of Materials Science and Chemistry,China University of Geosciences,Wuhan 430074,China)

机构地区：[1]中国地质大学(武汉)材料与化学学院,武汉430074

出　　处：《分析仪器》2025年第2期19-23,共5页Analytical Instrumentation

基　　金：陕西省技术创新引导专项(基金)计划项目,安康主要农作物富硒肥开发研究及应用示范(2022QFY09-02)。

摘　　要：将茶叶经70%的甲醇超声提取100min后,离心所得的上清液氮吹定容后用0.45μm的滤膜过滤。以8mmol/L(NH4)2HPO4~8mmol/LNH4NO3(p H 9.40)为流动相,于1.0m L/min下等度洗脱,可在10min内实现对6种砷形态的分离。分离后的6种砷形态{一甲基砷(MMA)、二甲基砷(DMA)、砷胆碱(As C)、砷甜菜碱(As B)、三价砷[As(Ⅲ)]和五价砷[As(Ⅴ)]}用电感耦合等离子体质谱仪测定。结果显示:质量浓度在2~200μg/L内与其对应的信号强度呈线性关系,检出限(3S/N)为0.41~0.70μg/L。对茶叶样品进行加标回收试验,回收率均在80%以上,测定值的相对标准偏差(n=6)为1.5%~2.88%。将该方法用于茶叶样品的测定,结果发现茶叶中砷主要以无机砷形态As(V)、As(III)存在,另外还含有少量的DMA。After ultrasonic extraction of tea with 70%methanol for 100minutes,the supernatant liquid obtained by centrifugation and nitrogen-blown was filtered using a 0.45μm membrane filter.Using 8mmol/L(NH4)2HPO4-8mmol/L NH4NO3(pH 9.40)as the mobile phase and isocratic elution at a flow rate of 1.0mL/min,the separation of six arsenic species can be achieved within 10minutes.The six arsenic species(MMA,DMA,AsC,AsB,As(III),As(V))were determined by inductively coupled plasma mass spectrometry.It was showed that linear ranges of the standard curves for the 6 arsenic species were 2-200ug/L,with detection limits(3S/N)in the range of 0.41-0.70ug/L.The tea samples were subjected to spiked recovery tests,and the recovery rates were all above 80%.The relative standard deviation(n=6)of the measured values was 1.5%to 2.88%.The test results showed that arsenic in tea mainly existed in the form of inorganic arsenic(As(V),As(III),and also contained a small amount of DMA.

关 键 词：超声提取 高效液相色谱-电感耦合等离子体质谱法 砷形态 茶叶 

分 类 号：O657.3[理学—分析化学]