涂镧石墨管-电热原子吸收法测定环境样品中微量钡

建立了硝酸镁作基体改进剂 ,镧涂层石墨管原子吸收法测定钡的方法 ,有效地避免了碳化物的生成 ,提高了测定灵敏度 ,测定土壤标样和环境水样中钡的含量。方法的检出限为 2 1× 10 - 1 2 g ,对于 15ng·mL- 1钡的测定相对标准偏差为 5 4%。

Determination of Trace Barium in Environmental Samples by Electric-heated AAS with Lanthanum-coated Graphite Tube

In this paper a new method was established for determination of trace barium in environmental samples by graphite furnace atomic absorption spectrometry. In the presence of matrix modifier magnesium nitrate, the matrix inference was eliminated efficiently. To avoid producing barium carbide, the graphite tubes were coated differently with lanthanum, zirconium, tungsten, molybdenum, and tantalum. Results showed that the tube with lanthanum was the best. The atomization temperature was diminished. The sensitivity was improved, and the tube with lanthanum gave the longest service life. So we used the tube to determine trace barium. The trace barium in Geodchemical Standard Reference Sample Soil-1 (GSS-1) was determined by the new method, the test results showed that the method was reliability and accurate. The method has been used for the determination of trace barium in environmental samples and in water of Yellow River. The detection limit for Ba was 2.1 x 10(-12) g and the relative standard deviation(RSD) was 5.4% for 15 ng.mL-1 Ba.