对用氢化物发生-原子荧光光谱法测定砷、镉、铅、汞、硒五元素时,溶液酸度对相关元素荧光强度的影响进行了试验,并提出了测定各元素时的最佳条件,所述酸度实际是指原子化前试液的综合酸度.试验结果表明,测定铅的溶液酸最严格,应控制在cHNO3 0.20~0.22 mol·L-1之间,与此相比,测定镉的酸度范围较宽,可允许在cHCl 0.20~0.31 mol·L-1范围内.而对砷、硒、汞的测定,酸度的影响最小,依次在cHCl>0.1 mol·L-1,cHCl>0.12 mol·L-1及cHNO3>0.16 mol·L-1的酸度条件下均能获得满意结果.

The effect of acidity of sample solution introduced into the atomizer after addition of the mixed solution containing KBH4 in the HG-AFS determination of As,Cd,Pb,Hg and Se were studied,and optimized conditions for their determinations were given.It was shown that the acidity of the solution was most critical for determination of lead,which should be controlled in a narrow range of cHNO3 0.20-0.22 mol·L-1.For the determination of cadmium,broader range of acidity between cHCl 0.20-0.31 mol·L-1 were tolerable.While for the determination of arsenic,selenium and mercury,the fluoresence intensity were very slightly effected by the acidity of test solution,and satisfactory results were obtained under the acidity of cHCl>0.1 mol·L-1 (for As),cHCl>0.12 mol·L-1 (for Se) and cHNO3>0.16 mol·L-1 (for Hg).