流动注射冷原子发生-原子荧光光谱法测定中药材中汞
FI-CV-AFS Determination of Mercury in Traditional Chinese Crude Drugs
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摘要: 提出了中药材中微量汞的冷原子发生-原子荧光光谱测定方法.采用微波技术用HNO3+H2O2消解样品,分取1.0 mL试样溶液用断续流动方式进样.荧光强度与汞的质量浓度在25 μg·L-1以内呈线性关系,检出限(3S)为0.02 μg·L-1.按此方法分析了10种药材,汞测定值的相对标准偏差(n=7)均小于5%,加标回收率在97.2%~102.7%之间.Abstract: Samples of traditional Chinese crude drugs were digested with HNO3 and H2O2 in closed vessel under pressure and heated in micro-wave oven.Aliquot portions of 1.0 mL of sample solutions were introduced with intermittent flow-injection mode into the AFS spectrometer and contents of mercury in micro amounts were determined by CV-AFS under the working conditions of the instrument described.Linear relationship between values of fluorescence intensity and concentration of mercury was obtained in the range within 25 μg·L-1,with detection limit(3S) of 0.02 μg·L-1.Ten samples of different crude drugs were analyzed by the proposed method.Values of RSD′s(n=7) calculated from the analytical results of mercury were all less than 5%,and values of recovery found by standard addition method were in the range of 97.2%-102.7%