艾氏卡试剂消化硫酸钡比浊法测定膨胀石墨中的硫含量

为了简便、准确、快速地测定膨胀石墨中的硫含量,建立了用艾氏卡试剂消化样品、硫酸钡比浊法测定硫含量的方法.实验确定艾氏卡试剂与膨胀石墨最佳物质的量比为1∶15,焙烧温度为850℃;比浊法中测试液的pH=1.0,质量分数为5%的聚乙烯醇分散剂和无水乙醇助稳定剂的用量分别为2.0 mL和3.0 mL;稳定10 min后,在460 nm下和0.1~5.0 mg内,硫酸钡的吸光度符合朗伯-比尔定律;方法平均回收率分别为101.2%(ZnS)和99.5%(Na2SO4),相对标准偏差均不超过3.0%.方法操作简便、准确,能快速测定膨胀石墨中的硫含量.

Detection of Sulfur in Expanded Graphite Combined Digestion Under Eschka Reagents with Turbidimetry of Barium Sulfate

In order to detect the content of sulfur in expanded graphite(EG),a simple,rapid and accurate method has been proposed.EG samples were digested by Eschka reagent at 850 ℃ with the amount of substance of 15∶1 to EG.The absorption of the BaSO4 emulsion was detected at the wavelength of 460 nm after static storage for 10 min.The pH of the detected emulsion was 1.0.A 2.0 mL of 5% polyvinyl alcohol solution and 3.0 mL ethanol was added as stabile reagent to ensure the formation of steady soliquid.BaSO4 in the range of 0～5.0 mg should be controlled by Lambert-Beer Law.With the RSD not more than 3.0%,the average recovery is 101.2% for ZnS and 99.5% for Na2SO4,respectively.The method is easy and fast to manage and reliable for sulfur measurement in the EG samples.