机构地区: 韩山师范学院化学系
出 处: 《中国调味品》 2011年第2期105-106,117,共3页
摘 要: 目的:探索测定食品中痕量铅的新方法。方法:以新试剂2-(2-氰基-4-硝基-6-溴苯偶氮)对苯二酚作为显色剂,研究分光光度法测定铅的优化条件。结果:在HAc-NaAc缓冲溶液中,铅(Ⅱ)与显色剂形成桔红色络合物,最大吸收波长为457nm,表观摩尔吸光系数ε=5.13×104 L.mol-1.cm-1,铅的质量在0~15μg/25mL范围内符合比耳定律。相对标准偏差为2.3%~2.8%。结论:该方法准确度、精密度良好,是一种简便、可靠的测定食品中铅的方法。 Objective: The aim was to explore the method for the determination of trace lead. Method: With 2-(2-Bromo-6-Cyano-4-Nitrobenzeneazo)Hydroquinone as the chromogenic reagent , the optimum of spectrophotometric determination of lead was studied. Result:In the buffer solution of HAc- NaAc ,lead could form orange complex with 2-(2-Bromo-6-Cyano-4-Nitrobenzeneazo)Hydroquinone. The maximum absorption of the complex occurred at 457 nm. The apparent molar absorptivity was 5.13× 104 L · mol^-1· cm^-1, and Beers lawwas obeyed in the range of 0- 15 μg/25 mL. , RSD was 2.3%-2.8%. Conclusion:The method has good accuracy and precision. It s a convenient and reliable method for analyzing tea.