石墨炉原子吸收法直接测定鸡蛋中的六价铬

Direct Determination of Cr(Ⅵ) in Eggs by Graphite Furnace Atomic Absorption Spectrometry Using Volatilization of Cr(TTA)3

基于Cr（Ⅲ）与噻吩甲酰三氟丙酮（TTA）生成的络合物在石墨炉中的挥发性,建立了一种前处理简单、灵敏度高的测定鸡蛋中六价铬的分析方法.研究了鸡蛋样品的消化方式、Cr（Ⅲ）与TTA络合的反应酸度、各种试剂的加入量、超声波水浴的温度和时间、静置时间等条件,并对石墨炉挥发Cr（Ⅲ）的原子化条件进行了探讨.测试液中Cr（Ⅵ）质量浓度在0.001～0.010 mg/L范围内呈良好线性关系,线性回归系数为0.999 7.鸡蛋样品中Cr（Ⅵ）不同加入量的平均回收率在75%～96%;相对标准偏差在3.5%～11.5%;定量下限为0.3 μg/L.

Based on the volatihzation of Cr（TTA）3 formed between Cr（Ⅲ） and thnoyhrifluroacetone, a novel and highly sensitive method was developed for the determination of Cr（Ⅵ） in eggs by graphite furnace atomic absorption spectrometry. The sample digestion mode and the effects of acidity, sonication time and temperature, reagent amount, and the reaction time on the formation of Cr（TTA）3 complex were studied in detail. The atomization conditions for volatilizing Cr（Ⅲ） in graphite furnace were discussed. The dynamic linear range for Cr（Ⅵ） is 0. 001 - 0. 010 mg/L with a correlation coefficient of 0. 999 7. The average recovery range of Cr（Ⅵ） in eggs is 75% -96% and the relative standard deviation range is 3.5% -11.5%. The limit of quantification（LOQ） is 0. 3 μg/L.