采用1 -(2-吡啶偶氮)-2-萘酚(PAN)为螯合剂,四氯化碳为萃取剂,丙酮为助溶剂,建立了析相微萃取-分光光度法测定化妆品中痕量铅的分析方法,并对影响络合反应和相分离的各种条件进行了优化.优化后的条件为:当水相体积为21.5 mL时,四氯化碳为2.0 mL,丙酮为1.5 mL,萃取时间为10 min.铅的质量浓度在0.20～13 μg/mL范围内与吸光度呈线性关系,相关系数为0.999 81,方法的检出限为0.01 μg/mL,对铅的质量浓度为1.0 μg/mL的样品溶液进行7次平行测定,相对标准偏差为1.98％.该方法用于化妆品中铅的测定,回收率为96.4％ ～ 103.4％.%A method for the determination of trace lead in cosmetics by spectrophotometry in combination with microsphere phase separation extraction was developed with 1 - ( 2 - pyridylazo) - 2 - naphthol ( PAN ) as chelating agent for Pb2+ , carbon tetrachloride as extraction solvent and acetone as solubili2er. Various conditions that affect the complexing reaction and phase separation were optimized. When the volume of water is 21. 5 mL,good extraction result can be obtained by using 2. 0 mL carbon tetrachloride and 1. 5 mL acetone with extraction time of 10 min. There was a linear relationship between absorbance and lead mass concentration in the range of 0. 20 -13 μg/mL with the correlation coefficient of 0. 999 81. The detection limit of this method was 0. 01 μg/mL. The RSD was 1. 98% for seven times of determination of a sample with lead content of 1.0 μg/mL. This method has been applied to the determination of lead in cosmetic samples with the recovery of 96. 4% - 103. 4% .
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