共振光散射法测定环境水样中痕量铬(Ⅵ)

Determination of Trace Chromium(Ⅵ) in Environmental Water by ResonanceLight-Scattering

研究了在磷酸介质中 ,铬 (Ⅵ ) -碘化钾 -吖啶橙(AO)体系的共振散射光谱 ,考察了它们的光谱特征 ,影响因素和适宜的反应条件 ;确定了散射光强度与溶液中Cr(Ⅵ)浓度的关系 ,提出了共振光散射法测定Cr(Ⅵ)的新方法 ;该法在室温下进行 ,操作方便 ,具有较高的灵敏度和较好选择性 ;线性范围为0.008～0.48mg/LCr(Ⅵ) ,方法的检出限为3.8μg/LCr(Ⅵ) ;用于环境水样中Cr(Ⅵ)的测定 ,结果满意。

The resonance light-scattering spectrum of Acridine orange in phosphoric acid medium was enhanced significantly in the presence of KI-Cr(Ⅵ) solution. The spectral characteristics, the affecting factors and the optimum conditions of the reaction were thus investigated. A new method based on the relationship of the intensity of resonance light-scattering to the concentration of chromium(Ⅵ) in water sample was established. This method can be operated conveniently at ambient temperature with high sensitivity and good selectivity. The detection limit and the linear range for Cr(Ⅵ) were 3.8 μg/L and 0.008～0.48 mg/L, respectively. The proposed method has been used to determine Cr(Ⅵ) in the environmental water sample with satisfactory results.