乙酸乙酯萃取进样-电感耦合等离子体原子发射光谱法测定矿石中金

Determination of gold in ore by ethyl acetate extraction injection-inductively coupled plasma atomic emission spectrometry

为了提高分析效率和降低分析成本,保证分析人员的身体健康,选择一种分析时间较短、试剂毒性较小、易操作的矿石中金测定方法尤为重要。样品采用王水溶解后,在分液漏斗中,选择试剂毒性较小、价格便宜的乙酸乙酯定量萃取,萃取液直接导入配备有机进样系统的电感耦合等离子体原子发射光谱仪(ICP-AES),选择Au I 242.795nm为分析谱线,对矿石中金进行测定,从而建立了电感耦合等离子体原子发射光谱法(ICP-AES)测定矿石中金的方法。采用萃取分离法消除基体元素及共存元素的干扰。通过对萃取酸度、萃取剂、萃取方法、仪器工作条件、分析谱线等条件试验,确定了最优的实验条件。金的质量浓度在0.10~16.00mg/L范围内与其发射强度呈线性,校准曲线线性相关系数为0.999 8。金检出限为0.02mg/L。按照实验方法测定5个矿石金标准物质中金,测定结果的相对标准偏差(RSD,n=10)小于3%;测定值和认定值比较吻合。方法可用于金质量分数在0.25~38.0g/t之间的矿样检测,单个样品的检测时间约4h,可用于批量检测。

In order to enhance the analysis efficiency and reduce the analysis cost,and ensure the health of analyst,the selection of one determination method for gold in ore with short analysis time,low reagent toxicity and easy operation is very important.The sample was dissolved with aqua regia followed by quantitative extraction in separating funnel with cheap ethyl acetate which had low toxicity.The extract liquor was directly injected into inductively coupled plasma atomic emission spectrometer(ICP-AES)equipped with organic injection system.Au I 242.795 nm was selected as the analytical line for the determination of gold in ore.Consequently the determination of gold in ore by inductively coupled plasma atomic emission spectrometry(ICP-AES)was established.The interference of matrix and coexisting elements was eliminated by extraction separation method.The optimum experimental conditions were obtained by the conditional tests of extraction acidity,extracting agent,extraction method,working conditions of instrument and analytical lines.The mass concentration of gold in range of 0.10-16.00 mg/L showed linearity to the corresponding emission intensity.The linear correlation coefficient of calibration curve was 0.999 8.The detection limit of gold was 0.02 mg/L.The content of gold in five certified reference materials of ore was determined according to the experimental method.The relative standard deviations(RSD,n=10)of results were less than 3%.The found results were consistent with the certified values.The proposed method could be applied for the ore detection with gold content in range of 0.25-38.0 g/t.The detection time for single sample was about 4 h.The proposed method could be used for batch inspection.