固相萃取-石墨炉原子吸收法测定食盐中铅

Determination of lead in edible salt with solid-phase extraction and GFAAS

目的建立固相萃取与石墨炉原子吸收联用测定食盐中铅的方法。方法食盐样品用乙酸铵溶液直接定容,样液流经预先活化好的固相萃取柱,保留富集其中的铅离子,同时去除不被保留的氯化钠,固相萃取柱经淋洗洗脱后,洗脱液用石墨炉原子吸收法在257.4nm处对铅进行测定。结果该方法能有效地去除氯化钠的基体干扰;样品检出限为0.7μg/kg;定量限为2μg/kg。结论使用固相萃取技术能有效地降低石墨炉原子吸收法测定食盐中铅的基体干扰,提高检测的准确性和重现性。

Objective Establishing a method for determination of lead in salt with solid-phase extraction and GFAAS. Methods Salt sample was diluted to a certain volume directly with ammonium acetate, then the sample solution was filtered through the solid phase extraction column which has been pre-activated. Lead ions were retained, and the sodium chloride matrix was removed. After elution,the collected lead ions was determined by graphite furnace atomic absorption spectrometry in 257.4nm. Results This method can be used effectively to wipe off the sodium chloride in matrix. The limit of detection was 0.7μg/kg and the limit of quantification was 2μg/kg. Conclusion Solid phase extraction technique can be used effectively to reduce the interference in matrix and improves the accuracy and reproducibility of detection.