磺基水杨酸光度法快速测定锰矿石中铁

Rapid determination of iron in manganese ore by spectrophotometry with sulfosalicylic acid

磺基水杨酸光度法是测定铁较常用的一种分析方法,但由于锰离子对铁的测定有干扰,因而实际工作中很少采用此法测定锰矿石中的铁。在pH 10左右的介质中,铁与磺基水杨酸生成相对稳定的2∶1黄色络合物,在420nm处有最大吸收峰,通过加入盐酸羟胺来消除锰矿石中锰的干扰,据此建立了磺基水杨酸光度法测定锰矿石中铁的分析方法。采用实验方法对锰矿石国家标准物质(GBW07262和GBW07263)中的铁进行了测定,测定值与认定值相一致,相对标准偏差(RSD,n=5)分别为3.1%和1.1%。对锰矿实际样品进行了分析,结果表明,未加盐酸羟胺时,测定结果严重偏高,加了盐酸羟胺之后本法的测定结果与国家标准方法 (GB/T 1508-2002)以及ICP-AES的测定结果基本一致。方法可用于各种品位锰矿石中铁的测定,特别适合大批量样品的分析。

Sulfosalicylic acid spectrophotometry is a common analytical method for the determination of iron, but it is rarely used in practical determination of iron in manganese ore according to the interfer- ence of manganese ion in the determination of iron. Iron and sulfosalicylic acid could generate relative- ly stable 2 ： 1 yellow complex which has a maximum absorption peak at 420 nm at around pH 10, and the interference of manganese in the manganese ore in the determination of iron was eliminated by adding hydroxylamine hydrochloride, hereby an analytical method was established for the determina- tion of iron in manganese ore by sulfosalicylic acid spectrophotometry. The method was applied to the determination of iron in national certified reference materials GBW07262 and GBW07263, and the re- suits were consistent with the certified values, giving the relative standard deviation （RSD, n--5） of 3.1% and 1.1%, respectively. The method was applied to the determination of iron in actual manga- nese ore samples and the measurement results were notably high in adding no hydroxylamine hydro- chloride and were consistent with those obtained by national standard method GB/T1508 -- 2002 and ICP-AES in adding hydroxylamine hydrochloride. The method could be used to determine iron in man- ganese ores of different categories, particularly is suitable for the analysis of large batches of samples.