冷原子吸收光谱法测定塑料玩具中可溶性镉

建立冷蒸气发生–原子吸收光谱法测试玩具中可溶性镉的检测方法。采用0.07 mol/L的盐酸溶液提取玩具中可溶性镉,在酸性介质中,还原剂硼氢化钠将镉离子还原生成镉蒸气,用载气将镉蒸气导入石英管,在波长228.8 nm处用原子吸收光谱法进行测定。选择溶液酸度介质为体积分数4%的盐酸溶液、NaBH4质量分数为2.5%、增敏剂加入量为2.0 mL。在优化的实验条件下,方法的检出限为0.065μg/kg。加标回收率为96.8%～104.2%,测定结果的相对标准偏差小于4.5%(n=11)。该方法具有快速、准确,灵敏度高,经济实用等优点,可用于塑料玩具中可溶性镉的测定。

Determination of Soluble Cadmium in Plastic Toys by Cold Vapor Atomic Absorption Spectrometry

A method for determination of the soluble cadmium in toys by cold vapor atomic absorption spectrometry was developed. 0.07 mol/L hydrochloric acid solution was used to extract the soluble cadmium in toys. Cd^2＋was reduced to Cd element by NaBH4 in acid medium. The cadmium vapor was carried into the quartz absorption tube by carrier gas and determined by atomic absorption spectrophotometry at the wavelength of 228.8 nm. 4%（volume fraction） hydrochloric acid solution was selected as acid medium,the mass fraction of NaBH4 was 2.5%,and the addition of sensitization reagent was 2.0 mL. Under the optimized conditions,the detection limit of the method for Cd was 0.065μg/kg and the recoveries were in the range of 96.8%-104.2%. The relative standard deviations of determination results were not more than 4.5%（n=11）. The method is rapid,simple and accurate. It can be used in the determination of the soluble cadmium in toys with the satisfactory results.