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目的以重金属铅(Pb)为测定对象,建立一种快速、高效、简便的检测方法测定食品中痕量的重金属,即流动注射(FI)空气混合法在线预富集与火焰原子吸收光谱法(FAAS)联用测定食品中痕量的重金属。方法样品溶液、络合剂和空气分别通过3条管子同时进样,金属离子和络合剂在线混合反应,其络合物流经编结反应器(KR)并吸附在其内壁,通入一段空气流,防止前后溶液混和并提高富集效果,用乙醇作为洗脱剂洗脱后送入火焰原子吸收光谱仪进行测定。结果与传统的流动注射与火焰原子吸收光谱法联用系统相比,此方法减少了样品的富集时间,达到了更好地吸附效果,提高了检测方法的灵敏度,线性相关系数良好(R>0.9983),检出限低,精密度好,加标回收率在97.3%~100.5%之间。结论该方法应用于沙丁鱼中重金属铅的测定,结果满意。
OBJECTIVE To establish a rapid, efficient and simple detection method for the determination of trace heavy metals in food by heavy metal lead (Pb) determination, that is, online pre-enrichment by flow injection (FI) air mixing and flame atomic absorption spectrometry FAAS) for the determination of trace amounts of heavy metals in foods. Methods The sample solution, complexing agent and air were injected simultaneously through three tubes. The metal ions and the complexing agent were mixed online. The complex was flowed through the braided reactor (KR) and adsorbed on the inner wall of the reactor. , To prevent mixing before and after the solution and improve the enrichment effect, using ethanol as the eluent eluent sent flame atomic absorption spectrometer for determination. Results Compared with the traditional flow injection and flame atomic absorption spectrometry system, this method can reduce the sample enrichment time, achieve better adsorption effect, improve the sensitivity of the detection method, and the linear correlation coefficient is good (R> 0.9983), the detection limit is low, the precision is good, and the recoveries of standard addition range from 97.3% to 100.5%. Conclusion The method was applied to the determination of heavy metal lead in sardines with satisfactory results.