碱熔融-分光光度法测定富铌渣中氟的探讨

Discussion on alkali fusion-spectrophotometric determination of fluorine in niobium-enriched slag

试样在750℃高温下被氢氧化钠一过氧化钠熔融，并用去离子水将其浸取并过滤，使氟元素富集于滤液中。显色过程中，以5mL丙酮为稳定剂、5mL茜素氨羧络合腙为显色剂，在温度为40~45℃的水浴中保温50min后，采用分光光度法测定溶液吸光度，并在校准曲线上查找氟量。干扰试验表明，滤液中可能存在的磷酸根、硅酸根等阴离子对测定无影响。方法用于富铌渣中氟量的测定，结果的相对标准偏差（RSD）为1．6％（n=10），加标回收率在99．99／6～104．09／6之间。

Sample was fused by sodium hydroxide-sodium peroxide at 750 ℃ and then leached and fil- trated with de-ionized water to enrich fluorine in the filtrate. During the process of color developing, 5 mL of acetone was used as stablilizer and 5 mL of alizarin complexon dehydrate was used as developer. The sample was kept in water bath at 40-45 ℃ for 50 min, then the solution absorbance was deter- mined with spectrophotometry, and the amount of fluorine was acquired with the calibration curve. It was showed through interference test that potential anions like phosphate radicals and silicate radicals had no interference with the determination. The method was applied to determine fluorine in niobium- enriched slag. The relative standard deviation （RSD） was 1.6% （n=10）. The standard addition re- covery -was 99.9 %-104.0%.