Uranium (U) associated with coal can be an important source of U and result in environmental pollution during coal combustion. In this study, we developed a method for measurement of U isotope ratios in coals using multiple-collector inductively coupled plasma-mass spectrometry. The ²³³U-²³⁶U double-spike was utilised to calibrate the instrumental isotopic fractionation. High-pressure bomb and dry ashing were adopted to digest the coal samples. The δ²³⁸U_CRM-145 values obtained from the two different digestion procedures were in good agreement. The δ²³⁸U_CRM-145 of seven coal and one fly ash reference materials are reported. Furthermore, the results of fly ash, bottom ash and feed coal samples reveal that the combustion processes lead to relatively small U isotopic fractionation between the samples within the same coal-fired power plant, indicating that U isotope data can be used as a tracer for heavy metal pollution resulting from coal combustion. The U isotope measurement method of coal established in this study provides technical support to understand the behaviour of U during coal formation and combustion.

中文翻译：

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MC-ICP-MS测定煤标准物质的δ238U

与煤伴生的铀（U）可能是铀的重要来源，并在煤炭燃烧过程中造成环境污染。在这项研究中，我们开发了一种使用多接收器电感耦合等离子体质谱法测量煤中铀同位素比率的方法。 233 U- ²³⁶ U 双尖峰用于校准仪器同位素分馏^。采用高压弹和干灰化的方法对煤样进行消解。从两种不同消化程序获得的δ ²³⁸ U _CRM-145 值非常一致。报告了七种煤和一种粉煤灰标准物质的δ ²³⁸ U _CRM-145 。此外，飞灰、底灰和原料煤样品的结果表明，燃烧过程导致同一燃煤电厂内样品之间的U同位素分馏相对较小，这表明U同位素数据可以用作示踪剂煤炭燃烧造成的重金属污染。本研究建立的煤U同位素测量方法为了解煤形成和燃烧过程中U的行为提供了技术支撑。