【摘要】 在0.2mol·L-1H2SO4介质中,偶氮氯膦 DBC(CPA DBC)与铬(Ⅵ)发生氧化褪色反应,该褪色反应的表观摩尔吸光系数ε550=2.35×104L·mol-1·cm-1,铬(Ⅵ)在0.040～0.60μg·ml-1范围内与吸光度差值呈良好线性关系。方法用于芹菜、大米、面粉中铬分析,结果满意。更多还原

【Abstract】 In a dilute acidic medium of c（H2SO4） 0.10～0.72mol·L^-1, CPA-DBC is oxidized by （Cr（Ⅵ））, leading to a fading of the color reagent. The decrease of color intensity （ΔA） of CPA-DBC was found to have a linear relationship with the concentration of Cr（Ⅵ） in the range from 0.040 to 0.60μg·ml^-1 and the apparent molar absorptivity （ε） was found to be 2.35×10⁴L·mol^-1·cm^-1 at 550nm which is the absorption maximum of CPA-DBC. This method has been applied to the determination of microamounts of Cr（Ⅵ） in celery, rice, and wheat flour with satisfactory results.更多还原