碱解-离子选择电极法测定冰晶石总氟含量
Determination of total fluorine content in cryolite by alkaline hydrolysis-ion selective electrode method
李睿琪 1陈志华 2陈义平 2姚岢岢 1池汝安 3龙秉文1
作者信息
- 1. 磷资源开发利用教育部工程研究中心,绿色化工过程省部共建教育部重点实验室,武汉工程大学,湖北 武汉 430205
- 2. 福建申芯电子材料有限责任公司,福建 福州 350000
- 3. 湖北三峡实验室,湖北 宜昌 443007
- 折叠
摘要
针对目前冰晶石总氟含量常规测定耗时长、操作烦琐、过程物质存在毒害性和测试成本高等不足,提出了碱解-氟离子选择电极法实现快速准确测定冰晶石中的总氟含量.样品预处理过程中,在 200℃下采用过量氢氧化钠在镍坩埚中碱解1h,可将冰晶石中的氟完全转换为氟离子.溶液电位测量过程中,在样品溶液和氟离子标准溶液中加入TISAB Ⅳ总离子强度调节缓冲溶液来消除Al3+的干扰,同时在氟离子标准溶液中加入适量Na+和Al3+来保证样品溶液和标准溶液的总离子势和Na+浓度一致.实验结果表明,该方法与传统化学分析法一致性良好,平均相对偏差为0.40%,最大绝对偏差为 0.32%,且 5 次平行测量相对标准偏差小于 0.50%,适用于冰晶石总氟含量的快速批量测定,亦可推广用于其他氟化物中总氟含量测定.
Abstract
The existing conventional determination methods for total fluorine content in cryolite have shortcomings such as long testing time required,complicated operation,toxic substances involved,and high testing cost.In order to overcome these shortcomings,an alkali hydrolysis-fluoride ion selective electrode method is proposed to determine total fluorine content in cryolite.In the sample pretreatment process,cryolite has been decomposed by excess sodium hydroxide in a nickel crucible at 200℃for 1 h to facilitate all fluorine to be converted into ionic form.Then,TISAB Ⅳ solution is added into both cryolite sample solution and fluoride ion standard solution to eliminate the interference caused by Al3+and to stabilize the solution's pH value.Besides,appropriate amount of Na+and Al3+are added in the fluoride ion standard solution to keep the total ionic strength and Na concentration consistent between the sample and standard solutions.Experimental results indicate that the accuracy of the proposed method is in excellent with that of the conventional chemical analysis method,showing an average relative deviation and maximum absolute deviation of 0.40%and 0.32%,respectively,and the relative deviation of five repeated measurements is less than 0.5%.Therefore,the proposed method works well for the fast determination of large quantity samples and can be extended to determine other fluorides.
关键词
离子选择性电极/冰晶石/氟元素/测定Key words
ion-selective electrode/cryolite/fluorine element/determination引用本文复制引用
基金项目
国家自然科学基金(22078250)
国家自然科学基金(U23A20604)
湖北三峡实验室创新基金(SC211012)
武汉工程大学教育创新基金(CX2023043)
出版年
2024
NETL
NSTL
万方数据