报道了一个改进的卡洛斯管溶样等离子体质谱法测定地质样品中铂族元素及Re含量的新方法。将封闭的卡洛斯管置于高压釜中,然后在高压釜中加水,密封在高压釜中的水在高温下产生的外压将会抵消卡洛斯管中由酸产生的内压,这样就可以避免传统的卡洛斯管在高温高压下可能发生爆炸的危险。由此可以加大取样量,降低铂族元素测定过程中的块金效应及检出限,使超低含量铂族元素的测定成为可能。12g样品在75mL卡洛斯管中用35mL王水于320℃溶解15h,基本上可以使各种地质样品中的铂族元素矿物完全溶解。一次溶样可以测定全部铂族元素及Re,全流程空白值极低,国际标样测定结果稳定可靠。
An improved Carius tube technique is developed for digesting geological samples in the determination of platinum group elements (PGEs). The Carius tube is placed in a custom made high pressure autoclave filled with water to balance the internal pressure of the Carius tube. As a result, the possible explosion of Carius tube can be avoided. Thus the sample size can be increased, and the nugget effect and detection limits can be decreased compared with normal Carius tube technique. This new technique is capable of digesting 12 g samples in a 75 mL Carius tube with 35 mL aqua regia at 320 ℃, and Re and all the PGEs can be measured. The procedural blank is very low and the results of international reference materials are excellent.