电感耦合等离子体原子发射光谱法测定辛酸铑催化剂中铂钯铅铁铜铝镍

Determination of platinum,palladium,lead,iron,copper,aluminum,nickel in rhodium octanoate dimer catalyst by inductively coupled plasma atomic emission spectrometry

准确测定辛酸铑催化剂中杂质元素含量,是判定产品是否合格的重要指标之一。以往常采用直流电弧发射光谱法(摄谱法)进行检测,但测定周期长,且重复性较差。用电感耦合等离子体原子发射光谱法(ICP-AES)测定辛酸铑催化剂中微量杂质元素时,辛酸铑催化剂样品中含有的大量有机组分和铑基体会对测定有严重干扰。实验采用反复滴加硝酸消解样品中有机组分,再用王水溶解盐类,选用合适背景点扣除的方式消除铑基体的干扰,建立了使用ICP-AES测定辛酸铑催化剂中0.001%~0.1%(质量分数)Pt、Pd、Pb、Fe、Cu、Al、Ni等7种微量杂质元素的方法。各元素在0.10~10.00μg/mL范围内与其发射强度呈线性关系,相关系数均大于0.999 9;方法检出限(μg/mL)为0.075(Pt)、0.003 3(Pd)、0.015(Pb)、0.003 6(Fe)、0.010(Cu)、0.001(Al)、0.012(Ni)。实验方法用于测定辛酸铑催化剂样品中Pt、Pd、Pb、Fe、Cu、Al、Ni,结果的相对标准偏差为(RSD,n=7)为1.4%~9.6%。按照实验方法测定辛酸铑催化剂中Pt、Pd、Pb、Fe、Cu、Al、Ni,并与直流电弧发射光谱法的测定结果进行比对,结果相一致。

The accurate determination of impurity elements in rhodium octanoate dimer catalyst was one of important indicators to judge whether the product was qualified or not. The common method in the past was direct current arc emission spectrometry (spectrographic method). However, the detection period was long and the repeatability was poor. The determination of trace impurity elements in rhodium octanoate dimer catalyst by inductively coupled plasma atomic emission spectrometry (ICP-AES) was seriously interfered due to the presence of many organic components and rhodium matrix in catalyst sample.The organic components in sample were digested by dropwise adding nitric acid repeatedly. The salts were then dissolved with aqua regia. The interference of rhodium matrix was eliminated by selecting appropriate deduction of background points. Thus, a determination method of seven micro impurities in rhodium octanoate catalyst (including Pt, Pd, Pb, Fe, Cu, Al and Ni with mass fraction of 0.001%-0.1%) by ICP-AES was established. The mass concentration of elements in range of 0.10-10.00 μg/mL was linear to the corresponding emission intensity with correlation coefficients higher than 0.999 9. The detection limit (μg/mL) of the method was 0.075(Pt), 0.003 3(Pd), 0.015(Pb), 0.003 6(Fe), 0.010(Cu), 0.001(Al) and 0.012(Ni). The experimental method was applied for determination of Pt, Pd, Pb, Fe, Cu, Al and Ni in rhodium octanoate dimer catalyst samples. The relative standard deviations (RSD, n =7) of the determination results were between 1.4% and 9.6%. The content of Pt, Pd, Pb, Fe, Cu, Al and Ni in rhodium octanoate dimer catalyst was determined according to the experimental method and the found results were consistent with those obtained by direct current arc emission spectrometry.