挥发化合物发生-原子荧光法测定水中痕量锌
Volatile compound Generation-Atomic Fluorescence Spectrometric Determination of Trace Amounts of Zinc in Environmental Water Samples
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摘要: 研究了挥发化合物发生-原子荧光光谱法测定环境水中痕量锌的可行性,着重优化了硼氢化钾与锌的反应条件,包括仪器和试剂条件.研究发现:适量镍离子和钴离子的存在能增强锌的荧光强度.在选定的最佳试验条件下,荧光强度与锌的质量浓度在0~1 200 μg·L-1范围内呈线性关系.对标准空白进行11次测定,方法检出限为0.53 μg·L-1;对400 μg·L-1锌进行11次测定,其相对标准偏差(RSD)为3.0%,平行测定8份水样,RSD为3.6%;分析了4种不同水样并做加入不同浓度锌(Ⅱ)标准溶液时的回收率试验,结果在98%~104%之间.Abstract: Conditions of the formation of zinc hydride by the reaction between Zn2+ and potassium borohydride (KBH4) was studied and its feasibility of hyphenation with atomic fluorescence spectrometry in the determination of traces of zinc in environmental water was tested.It was found that the presence of Ni2+ or Co2+ enhanced the fluerescence intensity of zinc to a remarkable extent,and that Ni2+ in the concentration of 120 μg·L-1 was chosen as sensitizing agent in the determination.Under the optimum conditions,linear relationship between the fluorescence intensity and concentration of Zn2+ ion was obtained in the range of 0 to 1 200 μg·L-1.From the data of eleven blank determinations,value of detection limit found was 0.53 μg·L-1.Precision of the method was tested at concentration level of 400 μg·L-1 for 11 determinations,value of RSD found was 3.0%.When 8 portions of a water sample were analyzed for its zinc content,value of RSD obtained was 3.6%.In application of the method to analyze 4 different water samples,test for recovery was made by addition of Zn2+ standard solution at different concentrations,values of recovery in the range from 98% to 104% were obtained.