正交试验优化石墨炉原子吸收光谱法测定海水中的总铬  

Determination of Total Cr in Seawater by GFAAS Method Optimized by Orthogonal Test

作　　者：曹珺[1] 雷知生[1] 张欣[1] 

机构地区：[1]广州海洋地质调查局,广州510075

出　　处：《化学分析计量》2015年第5期35-38,共4页Chemical Analysis And Meterage

摘　　要：建立了测定海水中总铬的石墨炉原子吸收光谱法。利用抗坏血酸作为基体改进剂，针对灰化温度、灰化时间、原子化温度、基体改进剂加入量4种因素，利用正交试验优化了石墨炉原子吸收光谱法测定海水中总铬的实验条件。结果表明：原子化温度对测试过程的影响最大，正交试验的最优测试条件：灰化温度1300℃，灰化时间20s，原子化温度2400℃，抗坏血酸质量分数为5％。在优化条件下，校正曲线的相关系数为0．9998，测定结果的相对标准偏差为3．80％（n=12），样品加标回收率在98．2％～109．2％之间。该法适用于测试大洋海水中的总铬含量。Ascorbic acid being used as matrix modifier, four facts being optimized by orthogonal test including ashing temperature, ashing time, atomic temperature and quantity of ascorbic acid, a direct determination of total Cr in seawater by GFAAS was set up. The result showed that atomic temperature was the main factor to influence the test. The optimized test conditions were as the follow： ashing temperature was 1300℃, ashing time was 20 s, atomic temperature was 2 400 ℃ , and ascorbic acid mass fraction was 5%. The linearity correlation coefficient of the calibration curve was 0.999 8, the relative standard deviation of the results was 3.80% （ n=12 ）, and the recovery of samples distribute was in the range of 98.2%-109.2%. The method can be used to determine Cr in seawater accurately.

关 键 词：正交试验 石墨炉原子吸收光谱法 海水 总铬 

分 类 号：O657.3[理学—分析化学]