Volatile compound Generation-Atomic Fluorescence Spectrometric Determination of Trace Amounts of Zinc in Environmental Water Samples

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.