热电离飞行时间质谱法用于铀矿勘查的铅同位素示踪

Lead Isotopic Tracing for Uranium Exploration by Thermal Ionization Time-of-flight Mass Spectrometry

在自行研制的低成本热电离飞行时间质谱仪(TI-TOF-MS)基础上,开展了应用TI-TOFMS法测定铀矿钻孔样品中铅同位素示踪铀矿勘查的研究。文中介绍了样品的前处理,铅的分离和富集步骤,仪器测量及数据处理等。TI-TOF-MS法测量铅同位素比值^(204)Pb/^(206)Pb、^(207)Pb/^(206)Pb和^(208)Pb/^(206)Pb的精密度分别为0.94%、0.37%和0.14%,可满足铀矿同位素示踪的要求。通过对北方某铀矿钻孔岩心取样的测量结果表明,TI-TOF-MS测量铅同位素的方法能够用于示踪铀矿。

Lead isotopic tracing is an effective method for uranium exploration, but it was not widely used due to the expensive instrument. The successful development of thermal ionization time-of-flight mass spectrometry （TI-TOF-MS） provided the possibility of using lead isotopes tracing economically in uranium exploration. Based on the laboratory-made economic TI-TOF-MS, the samples collected from the drill hole of uranium deposit in North China was analyzed for lead isotopic tracing experiment. The method of sample digestion, separation and enrichment of lead was introduced at first, and then the analysis ~ data processing procedure. TI-TOF-MS has an accuracy of 0. 94%, 0.37% and 0.14% for the measurement the ratio of 204 pb/206 Pb,207 pb/206 Pb and 508 pb/206 Pb, which met the requirement of lead isotopic tracing. The application results suggest that the composition of lead isotopes by TI-TOF-MS can be used as the sign for uranium exploration.