目的 比较湿法消解和微波消解2种前处理方法的处理效果,选择适合不同基质食品中总砷测定的前处理方法.方法 分别采用湿法消解和微波消解的方法对样品进行前处理,利用氢化物-原子荧光光谱法测定紫菜粉、扇贝、大米粉和鸡肉中总砷的含量.结果 砷的质量浓度在2~20μg/L内与其对应的荧光强度呈线性关系,方法检出限为0.0068 mg/kg,加标回收率为91.5%~99.6%,所有测定值的相对标准偏差(relative standard deviation,RSD)(n=4)均小于5%.紫菜和扇贝湿法消解测定的总砷结果在参考值范围内,微波消解测定的总砷结果明显低于参考值;大米和鸡肉用微波和湿法消解测定的总砷结果均在参考值范围内.结论 对于海产品等砷存在形态复杂的食品中总砷的测定,适合采用湿法消解进行前处理,而对于砷存在形态相对简单的食品,微波和湿法消解均适用.%Objective To choose suitable pretreatment method for determination of total arsenic in different matrix foods by comparing wet and microwave digestion methods. Methods The content of the total arsenic in seaweed powder, scallops, rice and chicken were determined by atomic fluorescence spectrometry with wet and microwave digestion, respectively. Results Linear relationships between the fluorescence intensity and concentration of arsenic were found in the range of 2~20 μg/L, the detection limit was 0.0068 mg/kg, and recoveries were found in the range of 91.5%~99.6%, RSD values (n=4) were less than 5%. The detection values of seaweed and scallops quality control samples with wet digestion were within the reference ranges, but the values with microwave digestion were significantly lower than the reference ranges. The detection values of rice and chicken quality control samples with wet and microwave digestion were within the reference ranges. Conclusion The method of wet digestion is suitable for determination of total arsenic in foods with complex forms of arsenic, such as seafood, while microwave digestion and wet digestion are both suitable for the determination of arsenic in foods with simple forms of arsenic.
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