氢化物发生-原子荧光光谱法测定硒中微量铋

Determination of trace bismuth in selenium by hydride generation-atomic fluorescence spectrometry

硒样品经硝酸和盐酸溶解后,加入氯化羟胺将硒(Ⅵ)还原成单质硒,使基体与杂质元素分离,用氢化物发生-原子荧光光谱法测定样品中微量铋.研究了氢化物发生的介质和酸度、硼氢化钾溶液浓度、预还原剂用量、预还原时间、氯化羟胺用量、共存元素等因素对测定结果的影响.在最佳测定条件下,铋的质量浓度在0～100 ng/mL范围内与荧光强度呈良好线性关系,相关系数大于0.9995,方法的检出限为0.18 ng/mL,加标回收率在96%～106%之间.本法测得结果和电感耦合等离子体原子发射光谱法(ICP-AES)基本一致,相对标准偏差(n=11)小于10%.

After the selenium sample was dissolved with nitric acid and hydrochloric acid, hydroxylammonium chloride was added to reduce selenium（VI） to elementary selenium, realizing the separation of matrix from impu- rity elements. Then, the content of bismuth in sample was determined by hydride generation-atomic fluorescence spectrometry. The effects of medium and acidity in hydride generation, potassiun borohydride concentration, dos- age of pre-reduction reagent, pre-reduction time, dosage of hydroxylammonium chloride and coexisting elements on the determination results were investigated. Under the optimum conditions, the concentration of bismuth in range of 0-100 ng/mL had good linearity to the fluorescence intensity with correlation coefficient higher than 0.9995. Detection limit of this method was 0.18ng/mL.The addition recovery is between 96% -106%.The results determinated by proposed method were consistent with those obtained by inductively coupled plasma atomic emission spectrometry （ICP-AES） with relative standard deviation （RSD, n=11） less than 10%.