铝锂合金样品的前处理及其Ag和Li的光谱分析

针对铝锂合金样品检测其Ag和Li，采用等离子体原子发射光谱法(ICP-OES)同时测定Ag和Li，火焰原子吸收光谱法(FAAS)分别测定Ag和Li，单宁酸分光光度法(VS)测Ag，对不同的光谱测定方法进行了比较，证明了ICP-OES检测铝锂合金中的Ag和Li具有较高的抗干扰性。对比了三种不同的样品消解方法，确定了FAAS测Li采用王水溶样最佳，ICP-OES，FAAS和VS测Ag采用HCl+H₂O₂体系溶样准确度更高。详细讨论了样品中共存元素Al, Mg, Zr, Ti, Cu的干扰及消除方法。用氨水沉淀消除共存元素Al，Ti，Zr，8-羟基喹啉沉淀分离Mg和Cu的方法消除原子吸收光度法测Ag的干扰;采用磷酸盐沉淀分离Ti而消除原子吸收光度法测Li的干扰;采用与原子吸收光度法测银相同的消除干扰方法，消除上述离子干扰，滤去干扰沉淀后，用硝酸赶盐酸解蔽Ag+离子，同时分解消除8-羟基喹啉的颜色，以消除分光光度法测银的干扰。对比消除干扰前后的结果发现准确度显著提高，证明消除干扰的方法切实有效。将选择的最佳消解体系和干扰消除方法应用于铝锂合金样品的测定，ICP-OES测Li和Ag回收率分别在100.39%～103.01%和100.42%～103.73%之间，FAAS测Li和Ag 回收率分别在95.91% ～99.98%和98.04%～103.67%之间，分光光度法测Ag回收率在98.00%～101.00%之间，测定结果满足分析要求。

Pretreatment of Aluminum-Lithium Alloy Sample and Determination of Argentum and Lithium by Spectral Analysis

Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), Flame Atomic Absorption Spectrometry (FAAS) and Visible Spectrometry (VS) was applied for determination of Ag and Li in lithium-aluminium alloy standard sample and test sample, their respective advantages and disadvantages were compared, the excellent selectivity of ICP-OES was confirmed by analyses of certified standard sample. Three different sample digestion methods were compared and discussed in this study. It was found that the better accuracy would be obtained by digesting sample with chloroazotic acid while the content of Li was measured by FAAS, and it was better to digest sample with hydrochloric acid and hydrogen peroxide while determining Ag and Li by ICP-OES simultaneously and determining Ag by FAAS and VS. The interference of co-existing elements and elimination methods was detailedly discussed. Ammonium hydroxide was added to adjust the sample solution into alkalescent and Al, Ti, Zr was precipitated by forming hydroxide precipitation, Mg and Cu was formed complex precipitation with 8-hydroxyquinoline in this condition, then the interference from matrix element to determinate Ag by FAAS was eliminated. In addition, phosphate was used to precipitate Ti to eliminate its interference for determination of Li by FAAS. The same treatment of determination for Ag by FAAS was used to eliminate the interference of matrix element for determination of Ag by VS, the excess of nitrate was added into sample and heated to release Ag+ from silver chloride complex, and the color of 8-hydroxyquinoline was eliminated because of decomposed by heating. The accuracy of analysis result for standard sample was conspicuously improved which confirms the efficient of the method to eliminate interference in this study. The optimal digestion method and eliminate interference method was applied to lithium-aluminium alloy samples. The recovery of samples was from 100.39% to 103.01% by ICP-OES determination for Ag, and from 100.42% to 103.01% by ICP-OES determination for Li. The recovery ranged from 95.91% to 99.98% by FAAS determination for Ag, and ranged from 98.04% to 99.98% for FAAS determination of Li. The recovery was from 98.00% to 101.00 by VS determination for Ag, the analysis results all meet the analysis requirement.