浓缩柱富集-流动注射分光光度法测定食品接触材料中的微量铅

Spectrophotometric determination of trace lead in food contact materials by concentrated enrichment-flow injection analysis

目的采用低压浓缩柱来富集食品接触材料提取液中的微量铅。方法样品用煮沸的4%乙酸浸泡,后经流动注射系统(FIA)与甲基百里酚蓝(MTB)螯合显色,最后用分光光度法进行测定。结果在最佳实验条件下,该方法在2~90μg/L的范围内,铅质量浓度与峰高成良好线性关系,相关系数r=0.9991,相对标准偏差为1.6%(20μg/L Pb, n=10),方法的检出限为0.34μg/L。结论这种低压浓缩柱对溶液中的微量铅具有良好的富集作用,与FIA联用,可实现快速在线分析。

Objective To enrich trace lead in food contact materials by low concentration column. Me-thods Samples were extracted by 4%boiled acetic acid, reacted with methyl thymol blue in FIA. Chelate was de-tected by spectrophotometry. Results The linear range of standard solutions was from 2 μg/L to 90 μg/L (correla-tion coefficient r=0.9991). The relative standard deviation (RSD) was 1.6%(n=10) obtained by injecting standard solution with 50μg/L lead. The detection limit was 0.34 μg/L. Conclusion This new concentration column is feasible in the enrichment of trace lead from aqueous solutions. It can be used as a fast online analysis method combined with FIA.