二安替比林基-(3,4-二甲氧基)苯基甲烷光度法测定微量铬

Spectrophotometric Determination of Chromium (Ⅵ) with Diantipyryl-(3,4-dimethyloxy )-phenylmethane

合成和鉴定了二安替比林基-(3,4-二甲氧基)苯基甲烷(DADMM),并研究了其与Cr(Ⅵ)的显色条件。在Mn(Ⅱ)存在下,试剂与Cr(Ⅵ)反应生成橙黄色产物,λ_(max)=465nm,ε=8.45×10~5L·mol^(-1)·cm^(-1),Cr(Ⅵ)量在8～56ng/ml范围内符合比尔定律。该体系稳定时间在3h以上,重现性好。用于电镀废液及球铁中Cr(Ⅵ)的测定,结果满意。

Diantipyryl-(3,4-dimethyloxy)-phenylmethane(DADMM) was synthesized and identified. Cr ( Ⅵ) reacts with DADMM in the presence of Mn ( Ⅱ ) to form an orange product in phosphoric acid medium. Maximum absorbance is at 465nm with molar absorptivity of 8. 45 ×105 L· mol-1 ·cm-1. Beer's law is obeyed in the range 8 ~ 56ng/ml. The method has been satisfactorily applied to the determination of trace Cr( Ⅵ ) in electroplating wastes and ferroalloys.