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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 To establish a method for the determination of lead in common salt by solid phase extraction and graphite furnace atomic absorption spectrometry. Methods The salt samples were directly fixed with ammonium acetate solution and the sample solution was passed through a pre-activated solid-phase extraction column to keep the lead ions enriched therein while removing un-retained sodium chloride. The solid-phase extraction column was washed by rinsing After off, the eluent was determined by graphite furnace atomic absorption spectrometry at 257.4 nm. Results The method can effectively remove the matrix interference of sodium chloride; the detection limit of the sample is 0.7μg / kg; the limit of quantification is 2μg / kg. Conclusion The solid-phase extraction technique can effectively reduce the matrix interference of lead in the salt by graphite furnace atomic absorption spectrometry, and improve the accuracy and reproducibility of the detection.