摘要
〔目的〕探讨石墨炉原子吸收光谱法直接测定食盐中铅的方法。〔方法〕采用氯化钯作基体改进剂 ,提高灰化温度 ,减少原子化阶段的气相干扰 ,试验找出最佳测定条件。〔结果〕加入氯化钯作基体改进剂 ,最佳灰化温度 10 0 0℃、原子化温度 2 5 0 0℃。方法线性范围 0～ 160ng/ml ,相关系数 >0 .9990。三种浓度加标样品测定 ,回收率为 95 .2 %～ 98.8% ,RSD为 1.0 1%～ 4.2 0 %。方法检出限为 1.2 1μg/L。背景吸收值在 0 .0 2以下 ,能非常有效控制背景吸收在氘灯校正的范围之内。〔结论〕运用氯化钯作基体改进剂直接测定食盐中铅 ,关键是选择好灰化温度 ,降低氯化钠基体在原子化阶段的气相干扰。此法具有操作简便 ,空白值低 ,准确度、精密度高等优点 ,实验可行并结果满意。
〔Objective〕To determine lead in salt by GFAAS. 〔Methods〕 PdCl 2 was used as a matrix modifier to find the best condition by improving the cineration temperature and reducing the interference of gas phase in atomization stage.〔Results〕 The best cineration temperature and atomization temperature were 1000℃ and 25000℃,respectively.The linear range was 0～160 ng/ml,the correlation coefficient was over 0.9990,recovery 95.2%～98.8%,the relative standard deviation 1.01%～4.20%,detection limit 1.21 mg/L and background absorb under 0.02 for the method.〔Conclusions〕 The background interference of NaCl can be eliminated by using PdCl 2 as a matrix modifier.This method is simple,rapid,repeatable,sensitive and accurate and can be used for detection of lead in salt.
出处
《中国卫生检验杂志》
CAS
2004年第4期428-429,共2页
Chinese Journal of Health Laboratory Technology
