作者：邓翔^1,2

作者单位：1. 四川大学生物材料工程研究中心, 四川 成都 610064;
2. 四川医疗器械生物材料和制品检验中心, 四川 成都 610064

关键词：火焰原子吸收光谱法; 磷酸铁锂; 锂; 次灵敏线

摘要：

以锂的次灵敏线323.3 nm为分析谱线,采用火焰原子吸收光谱法测定磷酸铁锂中的高含量锂。通过研究酸介质、消电离剂和基体离子对锂测定的影响,以及进行共存离子干扰实验发现:在2%的硝酸介质中方法的灵敏度最佳;在标准溶液中加入基体离子,可以消除基体对锂测定的干扰;常见共存离子不干扰锂的测定。在优化的实验条件下,锂的检测线性范围为4~140 gmL-1,检出限(3)为2.0 gmL-1,对20.0 gmL-1的锂标准溶液连续测定11次,其RSD为0.05%。方法简便、快速、准确,检测线性范围广,避免了稀释操作带来的误差,可用于高含量锂的直接测定;方法用于磷酸铁锂样品测定,回收率在94%~103.7%之间,相对标准偏差(n=7)在1.04%~1.16%之间。

Flame atomic absorption spectrophotometric determination of lithium in lithium ferric phosphate using sub-sensitive spectral line

DENG Xiang^1,2

1. Engineering Research Center in Biomaterials, Sichuan University, Chengdu 610064, China;
2. Sichuan Testing Center for Biomaterials and Medical Devices, Chengdu 610064, China

Abstract: The high-content of lithium in lithium ferric phosphate was determined by flame atomic absorption spectrophotometry using sub-sensitive spectral line at 323.3 nm.The effects of acid medium, disionizer and matrix ions had been studied.The effects of concomitant ions had been studied too.The results proved that the sensitivity was the best in 2% HNO₃ aqueous solution, and the matrix effect could be eliminating with addition of matrix ions in standard solutions.The concomitant ions did not affect the determination of lithium.Under the optimized conditions, the linearity range of lithium was kept from 4 μg·mL^-1 to 140 μg·mL^-1 and the detection limit(3σ)was 2.0 μg·mL^-1.The relative standard deviation (n=11) was 0.05% for 20.0 g·mL^-1 lithium.This was a simple, rapid, accurate method with wide linearity range.It could avoid the error produced in the dilution operation, so it could be applied to determine high-content lithium in samples directly.The content of lithium in lithium ferric phosphate was determined by this method, giving values of recovery in the range of 94%-103.7% and RSD (n=7) in the range of 1.04%-1.16%.

Keywords: flame atomic absorption spectrophotometry; lithium ferric phosphate; lithium; sub-sensitive spectral line

2013, 39(5): 46-48  收稿日期: 2012-10-3;收到修改稿日期: 2012-11-28

基金项目: 

作者简介: 邓翔(1979-),男,重庆市人,助理研究员,硕士,主要从事理化分析研究。

参考文献

[1] Galbács Z, Axner O, et al. Assessment and application of diode laser induced fluorescence spectrometry in an inductively coupled plasma to the determination of lithium [J]. Spectrochimi Acta Part B,2005(60):299-306.
[2] Choi M S, Shin H S, Kil Y W. Precise determination of lithium isotopes in seawater using MC-ICP-MS[J]. Microchem J, 2010(95):274-278.
[3] Albero M I, Ortuío J A, García M S, et al. Novel flow-through bulk optode for spectrophotometric determination of lithium in pharmaceuticals and saliva[J]. Sens Actuators B, 2010(145):133-138.
[4] Tabata M, Nishimoto J, Kusano T. Spectrophotometric determination of lithium ion using a water-soluble octabromoporphyrin in aqueous solution[J]. Talanta,1998(46):703-709.
[5] Zerbinati O, Balduzzi F, Dell'Oro V. Determination of lithium in wines by ion chromatography[J]. J Chromatogr A, 2000(881):645-650.
[6] Nickus U, Thies H. Ion chromatographic determination of lithium at trace level concentrations Application to a tracer experiment in a high-mountain lake[J]. J Chromatogr A,2001(920):201-204.
[7] Chao J H, Tseng C L. Determination of low-level lithium in environmental water samples by neutron activation[J]. Appl Radiat Isot,1995,46(4):211-215.
[8] Cretin M, Alerm L, Bartroli J, et al. Lithium determination in artificial serum using flow injection systems with a selective solid-state tubular electrode based on nasicon membranes[J]. Anal Chim Acta,1997(350):7-14.
[9] Teixeira M F S, Bergamini M F, Bocchi N. Lithium ions determination by selective pre-concentration and differential pulse anodic stripping voltammetry using a carbon paste electrode modified with a spinel-type manganese oxide[J]. Talanta,2004(62):603-609.
[10] Magnin J L, Decosterd L A, Centeno C, et al. Determination of trace lithium in biological fluids using graphite furnace atomic absorption spectrophotometry variability of urine matrices circumvented by cation exchange solid phase extraction[J]. Pharm Acta Helv,1996(71):237-246.
[11] Zhao J X, Gao P J, Wu S N, et al. Superiority of nitric acid for deproteinization in the determination of trace lithium in serum by graphite furnace atomic absorption spectrometry[J]. J Pharm Biomed Anal,2009(50):1075-1079.
[12] 张玲,付大勇,李永坤. 锂离子电池正极材料中高含量锂的测定[J]. 电池,2004,34(1):73-74.
[13] 胡利娜,任兆刚. 磷酸亚铁锂正极材料中锂的测定[J]. 西华师范大学学报:自然科学版,2008,29(4):409-412.
[14] 王晓艳,王星,王玉峰. LiFePO₄化学成分测定[J]. 电源技术,2006,30(9):764-767.
[15] 薛光荣,夏敏勇. 用N₂O-C₂H₂火焰原子吸收光谱法测定电解液中锂[J]. 中国测试技术,2006,32(5):26-28.