研究了在硫酸介质中,铬(Ⅵ)氧化吖啶红荧光增强反应的最佳实验条件,建立了测定痕量铬(Ⅵ)的新的高灵敏度荧光分析法。该方法的检出限为0.6μg·L^-1,线性范围为2.0~32μg·L^-1,对含量为4.0和28μg·L^-1的Cr(Ⅵ)标准溶液进行11次平行测定,其相对标准偏差分别为2.0%和1.0%。该法用于电镀液、废铬酸洗液及合金钢中痕量铬(Ⅵ)的测定,与标准样品和二苯碳酰二肼分光光度法进行了对照,获得了满意结果。
A simple and highly sensitive fluorimetric method for the determination of Cr(Ⅵ) was developed in the present paper. The method is based on the fluorescence enhancement of acridine red with Cr( Ⅵ ) in the sulfuric acid medium. The effects of some experimental conditions on the determination of Cr(Ⅵ) were investigated in detail. The detection limit for Cr(Ⅵ) is 0. 6 μg·L^-1 , and the linear range of the determination is 2. 0-32 μg·L^-1. The relative standard deviation of 11 replicate measure- ments is less than 2.0%. The proposed method has been successfully used to determine Cr(VI ) in electroplating solution, waste chromic acid mixture, and alloy steel samples. The results obtained were compared with the certified values of Cr(Ⅵ) in standard samples and those provided by 1,5-diphenylcarbazide method with satisfaction.