冷原子吸收光谱法测定儿童首饰中可溶性镉

Determination of Soluble Cadmium in Children's Jewelry by Cold Vapor Atomic Absorption Spectrometry

研究了儿童首饰中可溶性镉的冷原子化反应体系。在酸性介质中,用硼氢化钠将镉离子还原为镉原子,用载气将镉蒸气导入石英管,原子吸收光谱仪在波长228.8 nm处进行测定。对载气流速、NaBH4浓度、增敏剂加入量和介质酸度的影响,以及共存离子的干扰进行了研究。方法简便快速,在优化的实验条件下,方法的检出限为0.05 mg/kg。加标回收率为98.3%~103.1%,相对标准偏差小于2.2%。该方法具有快速、准确、灵敏度高、经济实用等优点,用于儿童首饰中痕量镉的测定,结果令人满意。

The chemical reaction system used for determination of soluble cadmiun in childreffs jewelry by cold vapor atomic absorption spectrometry was studied. In acid medium Cd2＋ was reduced to Cd element by KBH4. 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. The influences of flow velocity of carrier gas, concentrations of NaBH4, volume of sensitization reagent, acidity of medium, interference of coexistence ions were tested. It concluded that this method is convenient and fast. Under the optimized conditions, the limit of detection of the method for Cd was 0.05 mg/kg and the recoveries were in the range of 98.3%-103.1% with relative standard deviation（RSD） below 2.2%. The method is fast, simple, accurate, highly sensitive and economical. It was used in the determination of trace cadmium in children＇s jewelry with satisfactory results.