微波消解-流动注射化学发光法快速测定调味品中的微量铬

Rapid Determination of Trace Chromium in Condiment by Flow Injection Chemiluminescence Method after Microwave Digestion

为快速测定调味品中的铬含量,以八角、白蔻、黑胡椒为样品,经微波程序消解后,用无水亚硫酸钠将Cr^(6+)还原成Cr^(3+),用流动注射化学发光体系测定调味品中的铬含量。结果表明:最佳条件下,铬在1.0×10-7~8.0×10-7 mol/L浓度范围内有良好的线性,相关系数r=0.9996。对1.0×10^(-13) mol/L Cr^(3+)测定的相对标准偏差RSD为3.2%(n=11),按3倍标准偏差计算的检出限为2.3×10-12 mol/L,八角、白蔻、黑胡椒中铬的质量比分别为14.97,23.13,39.28μg/g,加标回收率为91.84%~97.47%。该方法选择性好、快速灵敏,用于调味品中铬的测定,结果令人满意。

In order to rapid detect the trace chromium in condiment with flow injection combination chemiluminescence, take anise, white cardamom and black pepper as samples, after microwave treatment, Cr6＋ state is deoxidized into Cr3＋ by anhydrous sodium sulfite. The results show that a good linearity range is 1.0 × 10-7 - 8.0 ×10-2 mol/L for chromium standard solution determination under the optimal condition, the linear correlation coefficient is 0. 9996. The relative standard deviation is 3.2 % （n=11）for 1.0 × 10-13 mol/L Cr3＋ standard solution. The lowest detection limit of Cr3＋ is 2. 3 × 10-12 mol/L. The content of Cr in anise, black pepper, white cardamom samples is 14.97, 23.13, 39.28 μg/g respectively. The recoveries are 91.84% - 97. 47%. This method is fast and sensitive with good selectivity. Therefore, it can be used to determine the trace chromium in condiment with satisfactory analytical results.