亚硝基红盐-光度法测定垃圾渗滤液中镉量

Photometric Determination of Cadmium in Landfill Leachate with Nitroso R

在酸性条件下,镉(Ⅱ)与亚硝基红盐发生反应生成黄色络合物,其最大吸收波长位于644 nm,表观摩尔吸光率为6.06×10~4L·mol^(-1)·cm^(-1),线性范围为3.56×10^(-7)～2.8×10^(-5)mol·L^(-1),由此建立了测定镉的光度法。此法用于巯基棉分离富集后的垃圾填埋场渗滤液中镉的测定,测得结果与原子吸收光谱法的测定结果相符,算得相对标准偏差(n=6)为0.56%,平均回收率为99.6%。

In a slightly acidic solution of 1.5 × 10^-3 mol · L^-1 HCI, a colored complex was formed between CA（ Ⅱ ） and nitroso R salt, having its absorption maximum at 644 nm and apparent molar absorptivity （ε） of 6.06 × 10^4L · mol^-1 · cm^-1. Linearity range was found in the range of 3.56×10^-7-2.8× 10^-5mol · L^-1. Based on these facts, a method for determination of cadmium in landfill leachate was proposed. Cadmium（ Ⅱ ） in the sample was pre-enriched by the sulfhydryl cotton adsorption, eluted from the sulfhydryl cotton with 0. 01 mol · L^-1 HCl and finally determined by photometry. Six separate portions of the sample solution were taken for the analysis, and the results obtained were in consistency with the results obtained by AAS. Value of RSD （n=6） found was 0.56% and the average recovery obtained was 99.6%.