油酸改性的Fe_(3)O_(4)磁性固相萃取-火焰原子吸收光谱法测定环境水样中铅离子

Determination of lead ions in environmental water samples by oleic acid modified Fe_(3)O_(4) magnetic solid phase extraction-flame atomic absorption spectrometry

目的在四氧化三铁纳米粒子表面包覆油酸制得一种新型磁性纳米材料Fe3O4@OA,建立环境水样中铅离子的磁性固相萃取-火焰原子吸收分光光度测定法。方法采用化学共沉淀法合成四氧化三铁磁性纳米粒子并用油酸对其进行改性。用红外光谱仪(FT-IR)对制备的Fe3O4@OA磁性纳米材料的结构进行表征。采用磁性纳米材料Fe3O4@OA对环境水样中铅离子进行萃取,优化了萃取条件,在样品p H值为5.0、吸附剂用量为50 mg、吸附时间为10 min的条件下,采用火焰原子吸收分光光度法测定铅离子浓度。结果Pb2+浓度在0.05μg/ml~1.0μg/ml呈现良好的线性关系,回归方程为y=0.01152x-0.00022,线性相关系数为0.9994。方法的检出限为78.1μg/L,回收率为98.0%~103.4%,批内精密度和批间精密度分别为2.12%~3.86%和3.98%~5.64%。结论该方法操作简单、灵敏度高,可用于环境水样中Pb2+的分离富集与测定。

Objective A novel magnetic nanomaterial Fe_(3)O_(4)@OA was prepared by coating the surface of Fe_(3)O_(4)nanoparticle with oleic acid.A magnetic solid phase extraction-flame atomic absorption spectrophotometry method was developed for the determination of lead ions in environmental water samples.Methods The ferric oxide magnetic nanoparticle was synthesized by chemical coprecipitation method and modified by oleic acid.The structure of Fe_(3)O_(4)@OA magnetic nanomaterial was characterized by FT-IR.The magnetic nanomaterial Fe_(3)O_(4)@OA was used to extract lead ions from environmental water samples.The extraction conditions were optimized.The concentration of lead ions was determined by flame atomic absorption spectrophotometry under the conditions of p H 5.0,dosage of adsorbent 50 mg and adsorption time of 10 min.Results The method exhibited good linearity in the linear range of 0.05μg/ml-1.0μg/ml.The regression equation was y=0.01152x-0.00022.The correlation coefficient was 0.9994.The limits of detection was 78.1μg/L,good recoveries was within 98.0%-103.4%,and relative standard deviations was in the range of 2.12%-3.86%for intra-day and 3.98%-5.64%for inter-day.Conclusion The method is simple and sensitive and can be used for the separation,enrichment and determination of lead irons in environmental water samples.