基于ICP-MS/MS分析微量金属元素的原油产地溯源

建立电感耦合等离子体串联质谱(ICP-MS/MS)法测定原油中微量金属元素的分析方法，结合聚类分析(CA)建立判别模型，进行原油产地溯源研究。原油样品经微波消解处理后，采用ICP-MS/MS测定其中18种微量金属元素Mg、Al、Ti、V、Cr、Mn、Fe、Co、Ni、Cu、Zn、Rb、Sr、Mo、Ag、Cd、Ba、Pb的质量分数。在MS/MS模式下的碰撞反应池(CRC)中，应用O2或NH3/He为反应气可消除多原子离子对轻质量元素的干扰，采用国际标准物质燃油(NIST SRM 1634c)验证了分析方法准确可靠性，并利用多种微量金属元素质量分数的比值进行聚类分析。方法的检出限为0.43～59.2 ng/L，相对标准偏差(RSD)不大于4.82%；CA将18种原油聚为4大类，可实现原油产地的初步判别。通过微量金属元素的ICP-MS/MS分析，并结合CA能够对原油进行有效的产地溯源和判别。

Tracing the Geographical Origin of Crude Oils Based on Inductively Coupled Plasma Tandem Mass Spectrometry Analysis of Trace Metal Elements

An analytical method for the determination of trace metal elements in crude oils by inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) was established. Combining cluster analysis (CA), a discriminant model was established to trace the origin of crude oil in the different regions. The mass fractions of 18 trace metal elements including Mg, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Mo, Ag, Cd, Ba and Pb in crude oil samples were determined by ICP-MS/MS after microwave digestion. In the MS/MS mode, polyatomic interferences on the lighter mass elements could be eliminated using O2 or NH3/He as reaction gas in the collision/reaction cell (CRC) of the ICP-MS/MS. The accuracy and reliability of the analytical method were verified by analyzing the standard reference materials NIST SRM 1634c (trace elements in fuel oil). The mass fraction ratios of various trace metal elements were used for CA. The limits of detection ranged from 0.43 to 59.2 ng/L, and the relative standard deviation (RSD) was ≤4.82%. The CA classified 18 crude oil samples into four groups, which could realize the preliminary discrimination of crude oils. Combining ICP-MS/MS analysis of trace metal elements with CA, the origin of crude oils can be effectively traced and distinguished.