灰化法与微波消解法处理地电化学泡塑样品的分析效果对比研究

Comparison of Ashing and Microwave Digestion in Analyzing Geoelectrochemical Polyurethane Foam Samples

当前普遍使用灰化法对地电化学泡塑样品进行预处理,但可能存在高温下某些元素(如Hg、As)挥发损失的缺点。本文选择了内蒙古洛恪顿热液型铅锌多金属矿床一条地电化学勘查剖面,开展灰化法及微波消解法处理地电化学泡塑样品的勘查效果对比研究,采用原子荧光光谱和高分辨电感耦合等离子体质谱测定其中的主要元素。结果表明:1对于Zn、Cu、Fe、La等十余种元素,两种处理方法取得的异常模式基本一致,可根据实际工作需求任选一种方法进行样品预处理;2对于Au、Pb等元素,微波消解法因为取样量小,可能存在较严重的样品均匀性、代表性及分析检出限等问题,应采用灰化法;3对于Hg,灰化法存在显著的元素损失,更适合采用微波消解法;4对于As,两种方法均存在较大问题,建议参考植物样品尝试使用硝酸及高氯酸直接溶解等方法进行预处理。

Currently,the ashing method is widely used to pretreat geo-electrochemical polyurethane foam samples.However,there may be volatilization loss of some elements such as Hg and As under high temperature. A geoelectrochemical exploration line in Luokedun hydrothermal lead-zinc polymetallic deposit in Inner Mongolia was selected as the research subject. A comparison of the exploration effects between the ashing method and microwave digestion in pretreating foam samples was made,and the contents of some related elements by High Resolution Inductively Coupled Plasma-Mass Spectrometry( HR-ICP-MS) and Atomic Fluorescence Spectrometry( AFS) were measured. Results are as follows,1For more than ten elements including Zn,Cu,Fe,and La,abnormal patterns of the two methods were identical within uncertainty measurements and thus both methods can be used according to the work requirement. 2 For Au and Pb,microwave digestion has serious problems related to homogeneity,representative and detection limit due to the small sample volume,making ashing the more suitable method.3There is a significant loss in ashing for Hg,so microwave digestion is more suitable. 4For As,both analytical methods suffer a lot problems,therefore,dissolving the samples directly by nitric and perchloric acid using the pretreatment method for plant samples would be the preferable method.