灿烂黄褪色光度法测定调味品中铜含量

摘要

研究铜（Ⅱ）与1，10-菲啉和灿烂黄的络合反应，建立褪色光度法测定铜含量的新方法。通过试验优化酸度、1，10-菲啉用量、灿烂黄用量、反应温度和反应时间等测定条件。结果表明，最大褪色波长为474 nm，表观摩尔吸光系数为7．92×104 L／mol·cm，铜（Ⅱ）浓度在0～0．6μg／mL范围内服从比尔定律，检出限为4．89μg／L。方法用于测定调味品中铜含量，结果与原子吸收光谱法一致，相对标准偏差为1．02％～1．36％（n＝5），回收率为99．8％～102．1％。%Study the complexation reaction of Cu (Ⅱ)-1 ,10-phenanthroline monohydrate-brilliant yellow system,a new fading spectrophotometry for determination of copper content is established. The optimal determination conditions are studied after the experiments including acidity, 1 , 10-phenanthroline monohydrate and brilliant yellow dosage,reaction temperature and time.The results show that the maximum fading wavelength is at 474 nm.The apparent molar absorption coefficient is 7.92×104 L/mol·cm.Beer's law is obeyed in the concentration range of 0~0.6μg/mL for copper.The detection limit is 4.89μg/L.This method is applied for the determination of copper content in condiment.The results obtained by this method agree well with those obtained by atomic absorption spectrometry.RSD is in the range of 1.02%~1.36% (n= 5),and recovery is in the range of 99.8%~102.1%.