刚果红-巯基棉分离富集光度法测定垃圾渗滤液中镉

基于在pH值为4.0～5.2的BR缓冲介质中，镉与刚果红发生显色反应并生成蓝色离子缔合物的原理，建立了测定垃圾渗滤液中镉的巯基棉分离富集光度法。其最大正吸收波长和最大负吸收波长分别为604nm和492nm，线性范围分别为0.10mg／L～2.80mg／L和0.10mg／L～3．40mg／L，采用双波长叠加测定灵敏度更高。探讨了渗滤液的处理方法及共存离子对测定的影响，优化了试验条件，实际样品的测定结果与原子吸收法对比无显著差异，加标回收率为98，6％～104％。

The Determ ination ofCadm ium in LandfillLeachate by Congo Red and SulfhydrylCotton Preconcentraction Spectrophotometry

Cadmium（ Ⅱ ） reacts with congo red to form blue ion complexes in the BR pH 4.0 -5.2 buffer solution. A method was established for determination of cadmium in landfill leachate by spectrophotometry with sulfhydryl cotton preconcentraction. The maximum positive absorption wavelength was at 604 nmand maximum negative absorption wavelength was at 492 nm. The linearities ranged from 0.10 mg/L to 2.80 mg/L（positive absorption） and from 0.10 mg/L to 3.40 mg/L（negative absorption）. The method was sensitive at the positive and minus wavelengths overlapping absorption. The treatment of landfill leachate and interference of coexistent ion were discussed. The analytical parameters were optimized. The samples detective results of the method were on different with the results of atomic absorption spectrometry. The recoveries were 98.6% - 104%.