氢化物发生-原子荧光光谱法测定硒中微量铋

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％.

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

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 impurity 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,dosage 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%.