Photometric Determination of Cadmium in Landfill Leachate with Nitroso R

In a slightly acidic solution of 1.5×10-3mol·L-1 HCl,a colored complex was formed between Cd(Ⅱ) and nitroso R salt,having its absorption maximum at 644 nm and apparent molar absorptivity (ε) of 6.06×104L·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%.