密闭溶样-原子荧光光谱法测定硫磺中微量汞

采用原子荧光光谱法测定硫磺中微量汞。利用正交试验法研究了硝酸-双氧水密闭消化硫磺样品的溶解条件,确定了仪器最佳测试条件,探讨了硝酸介质、硼氢化钾浓度对测定结果的影响。在选定的仪器条件下,对食品级硫磺和工业级硫磺两种样品中的汞进行了测定,方法的检出限为0.012 7 ng/mL,回收率为98.0%~104.0%,精密度为2.00%~4.74%(n=11)。建立的方法具有灵敏度高、简便、结果准确、无环境污染的特点。

Determination of Micro-amount of Mercury in Sulfur by Atomic Fluorescence Spectrometry with Closed-vessel Digestion Method

A method for the determination of micro-amount of mercury in sulfur samples was developed.The samples were digested in closed-vessel and micro-amount of mercury in sample solution was determined by atomic fluorescence spectrometry.The digestion experiments were designed using orthogonal test.In the closed system,the complete digestion of the sample was performed using concentrated nitric acid and hydrogen peroxide.The effects of acidity of the medium and the amounts of KBH4 on sample digestion were studied and the operating conditions of the instrument were optimized.The detection limit(3σ) of Hg was 0.012 7 ng/mL and the recovery is 98.0%～104.0% with the precision of 2.00%～4.74%RSD(n=11).The method has been applied to the determination of micro-amount of mercury in foodstuff and industrial sulfur samples with advantages of high sensitivity,precision and accuracy,simple operation and less environmental contamination risks.