氢化物发生原子荧光光谱法测定轻烧镁和水镁石中砷汞

Determination of arsenic and mercury in calcined magnesite and brucite by hydride generation-atomic fluorescence spectrometry

试样经微波溶解，用抗坏血酸和硫脲作还原剂，氢化物发生原子荧光光谱法测定轻烧镁和水镁石中砷和汞。镁对测定的影响可通过基体匹配方法避免，样品中主要杂质和痕量元素无干扰。砷和汞的工作曲线线性范围分别为0～100ng／mL和0～10ng／mL，检出限分别为0．7ng／mL和0．02ng／mL。样品中砷和汞加标回收率分别为101．4％～107．1％和104．1％～108．5％。方法已用于轻烧镁和水镁石中砷和汞的测定。

A hydride generation - atomic fluorescence spectrometric method for the determination of trace arsenic and mercury in calcined magnesite and brucite was achieved. The samples were dissolved in mixed solution of HCI and H2O2 by microwave digestion. Arsenic and mercury in the sample solution were prereduced with ascorbic acid and thiourea,and finally determined by hydride generation atomic fluorescence spectrometry. Influence from large amounts of magnesium could be avoided by using matrix matching technique. Main impurity elements and trace elements didn＇t interfere with the determlnation. The calibration curves of arsenic and mercury gave a linear range of 0- 100 ng/mL and 0 - 10 ng/mL, respectively. The detection limits were 0.7 ng/mL and 0.02 ng/mL, respectively. The method was applied for the determination of arsenic and mercury in calcined magnesite and brucite with the recovery in the range of 101.4 %- 107.1% for arsenic, 104.1%-108.5% for mercury.