【摘要】 足金样品的检测有着广泛市场需求,但常用的火焰原子吸收光谱法(FAAS)、电感耦合等离子体原子发射光谱法(ICP-AES)对于铅、镉质量分数均小于0.000 1%的足金样品无能为力,而电感耦合等离子体质谱法(ICP-MS)标准加入校正-内标法不能用于银、铜含量高(质量分数均大于0.001%)的足金样品检测。采用王水溶解样品后直接用乙酸乙酯萃取,以2%~5%(体积分数)硝酸为测定介质,建立了ICP-MS测定纯度为99.9%~99.999%足金中铜、银、铅、镉4种主要杂质元素的方法。干扰试验表明,足金中高含量银对测定铜、铅、镉没有干扰。在选定的实验条件下,各元素校准曲线的相关系数不小于0.999 4,方法测定下限为0.01~0.19μg/g。将实验方法应用于足金实际样品分析,结果的相对标准偏差(RSD,n=6)为1.3%~2.6%,加标回收率为99%~105%。采用实验方法对3种纯度(99.9%、99.99%、99.999%)足金样品中的铜、银、铅和镉进行测定,测得结果分别与原子吸收光谱法(AAS)或ICP-MS标准加入校正-内标法基本一致。方法可实现纯度为99.9%~99.999%足金中银、铜、铅、镉的测定。更多还原

【Abstract】 The detection of pure gold sample has extensive market demand.However,the commonly used flame atomic absorption spectrometry(FAAS)and inductively coupled plasma atomic emission spectrometry(ICP-AES)were unable to determine pure gold samples when the mass fractions of lead and cadmium were both less than 0.000 1%.In addition,inductively coupled plasma mass spectrometry(ICP-MS)with standard addition correction-internal standard method could not be used for determination of pure gold samples with high content of silver and copper(the mass fraction were both higher than 0.001%).After the sample was dissolved with aqua regia,the sample solution was directly extracted with ethyl acetate.Then a determination method of four main impurity elements including copper,silver,lead and cadmium in pure gold with purity in range of 99.9%-99.999% by ICP-MS was established with 2%-5%(volume fraction)nitric acid as determination medium.The interference tests indicated that the high content silver in pure gold did not interfere with the determination of copper,lead and cadmium.Under the selected experimental conditions,the correlation coefficients of calibration curves for all tested elements were not less than 0.999 4.The low limit of determination was 0.01-0.19μg/g.The proposed method was applied for the analysis of pure gold actual samples.The relative standard deviations(RSD,n=6)of determination results were between 1.3% and 2.6%.The recoveries were between 99% and 105%.The experimental method was used for the determination of copper,silver,lead and cadmium in pure gold samples with three kinds of purity(99.9%,99.99% and 99.999%).The results were basically consistent with those obtained by atomic absorption spectrometry(AAS)or ICP-MS with standard addition correction-internal standard method.The proposed method was applicable for the determination of copper,silver,lead and cadmium in pure gold with purity in range of 99.9%-99.999%.更多还原