微波消解-双道原子荧光光谱法同时测定茶叶中砷和硒

建立了微波消解-双道原子荧光光谱法同时测定茶叶中微量砷和硒的方法。采用密闭微波消解技术,在避免砷、硒损失的同时,使茶叶样品消解完全。对影响原子荧光分光光度计灵敏度的实验参数进行了优化。探究了样品中潜在的共存元素对砷、硒同时测定的干扰问题。在优化条件下,该法对砷的检出限为0.043μg/L,对硒的检出限为0.140μg/L。将该法应用于市售茶叶中砷和硒含量测定,砷和硒的加标回收率均在95.3-107.9%之间;茶叶成分分析标准物质(GBW 10016)中砷和硒的含量测定结果与标准值相符。该法具有方便快速、灵敏稳定、准确可靠等优点。

Simultaneous Determination of Arsenic and Selenium in Tea by Double-channel Atomic Fluorescence Spectrometry Digested with Microwave

A method is developed for the simultaneous determination of arsenic and selenium in tea by double-channel atomic fluorescence spectrometry digested with microwave. The airtight microwave-digestion technique was used to digest the tea samples thoroughly and avoid the loss of arsenic and selenium in the meanwhile. The experimental parameters of atomic fluorescence spectrometry were optimized to get the favorable sensitivity. The interferences from potential coexisting elements of samples were evaluated. Under the optimized conditions, the detecting limit for arsenic was 0.043 μg /L, and 0.140 μg/L for selenium. This method was used to determine the arsenic and selenium of tea samples on sale, and the spiked recoveries were in the range of 95.3-107.9%. Arsenic and selenium in reference materials （tea,GBW10016） were also determined by this method. The detecting results were in agreement with the standard values. The method is rapid, sensitive, reliable, accurate and can be easily performed.