甲苯萃取-GFAAS法测定高盐食品中微量砷

Determination of trace arsenic in the salty food by GFAAS after toluene extraction

建立甲苯萃取-石墨炉原子吸收测定高盐食品中砷的方法。用微波消解样品,甲苯萃取分离砷,硝酸镍作基体改进剂,钯涂层石墨炉原子吸收法测定高盐食品中微量砷。结果表明：用甲苯萃取砷提高了回收率,很好地消除基体干扰;用硝酸镍作基体改进剂,提高砷的灰化温度和灵敏度,方法的相对标准偏差≤1.12%（n=6）;回收率达到97.5%-104.5%;检出限为0.038 mg/kg。该法灵敏、准确、可靠,可用于高盐食品中微量砷的测定。

A method for determination of arsenic in salty food samples by graphite furnace atomic absorption spectrophotometry（GFAAS） after toluene extraction is established. The samples are digested with a microwave system. Arsenic is extracted and separated from these samples with toluene. The Pd-coated GFAAS determins the contents of arsenic in samples with Ni（NO3）2as a matrix modifier. The results show that the recovery of arsenic has been improved after toluene extraction, the charring temperature enhanced, and the interference of matrix eliminated.The relative standard deviation of this method is equal or less than 1.12%（n =6）. Recoveries ranging from 97.5% to 104.5% are obtained in the spiked samples. The detection limit is 0.038 mg/kg.The proposed method is sensitive, accurate and credible, which can be used to measure trace arsenic in salty food.