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目的为了实现将痕量铅从咸味食品样品中分离,消除盐类基体对测定铅的干扰,建立了黄原脂棉的最佳制备方法。方法利用单因素试验和正交试验,对制备黄原脂棉的工艺条件氢氧化钠乙醇溶液浓度、苛化反应时间、磺化反应时间、烘干温度进行试验优化,并利用石墨炉原子吸收分光光度法对痕量铅进行测定。结果制备黄原酯棉的最佳工艺条件分别为:氢氧化钠乙醇溶液浓度为1%(m/V),振荡苛化反应时间为15 min,二硫化碳磺化反应时间为20 min,烘干温度为50℃。实际样品平行测定6次的相对标准偏差(RSD)为1.56%~2.31%;加标回收率为97.0%~102.7%;方法检出限为0.047 mg/kg。结论本工艺方法制备的黄原脂棉实现了铅与高盐基体的有效分离和富集,有效地消除了基体干扰。该测定方法快速、操作简单、灵敏、准确、可靠,可用于咸味食品中痕量铅的测定。
In order to achieve the separation of trace amounts of lead from savory food samples and eliminate the interference of salt matrix on the determination of lead, the optimum preparation method of yellow cotton was established. Methods The single factor experiment and orthogonal experiment were used to optimize the process conditions of sodium alginate, such as the concentration of NaOH solution, the causticizing reaction time, the sulfonation reaction time and the drying temperature. Graphite furnace atomic absorption spectroscopy Photometric method for the determination of trace lead. Results The optimal conditions for the preparation of xanthate were as follows: the concentration of sodium hydroxide in ethanol was 1% (m / V), the reaction time was 15 min, the reaction time was 20 min, the drying temperature Is 50 ° C. The relative standard deviations (RSDs) of six parallel determinations of real samples were 1.56% ~ 2.31%. The recoveries were 97.0% ~ 102.7%. The detection limit was 0.047 mg / kg. Conclusion The yellow cotton liquefied cotton prepared by this process method can effectively separate and enrich the lead and high salt matrix and effectively eliminate the matrix interference. The determination method is rapid, simple, sensitive, accurate and reliable, and can be used for the determination of trace amounts of lead in savory foods.