1.1 本规程为通过电感耦合等离子体质谱（ICP-MS）测定适当制备的水溶液中选定的锕系同位素的替代线性校准提供了指导。该替代校准使用钍-232进行质量偏差调整( 232 Th）和铀-238( 238 U） 标准。该标准实践的好处之一是能够在比放射性低得多的情况下使用校准标准对高放射性锕系元素的分析进行校准。 如果设施不可用于处理感兴趣的单个锕系元素的高放射性标准，环境实验室可能会发现该标准实践很有用。 1.2 一系列已知浓度测定的仪器响应 232 Th和 238 U定义了质量与响应的关系。对于每个标准浓度，由以下公式定义的线斜率: 232 Th和 238 U用于使用干涉方程推导每个感兴趣质量的线性校准曲线。 质量偏差校正校准曲线虽然由干扰方程生成，但特定于数据采集时有效的仪器操作参数和调谐。由于干扰方程是正常ICP-MS制造商软件包的一部分，因此该校准方法具有广泛的适用性。 1.3 对于本标准实施规程，已研究的锕系元素原子质量范围为AMU 232至244。本规程中给出了AMU 228至248扩展范围的指南。 1.4 使用本规程，在每个AMU处报告分析物浓度，而不是按元素总量（即， 239 钚与钚）。 1.5 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 1.6 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.7 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 本标准实施规程的一个优点是能够在比放射性低得多的情况下使用校准标准对高放射性锕系元素的分析进行校准（即， 232 Th和 238 U） 。如果设施不可用于处理感兴趣的单个锕系元素的高放射性标准，环境实验室可能会发现该标准实践很有用。 5.2 实际质量偏差的程度是可变的，取决于仪器调谐参数。本标准惯例使用通用干扰方程推导质量偏差校正，该校正特定于用于样本数据采集的仪器参数和调谐，而不是基于历史平均值。 5.3 质量偏差校正使用仪器软件干扰方程，不需要额外的后续离线计算。 5.4 本标准实施规程所依据的方法已用于确定 232 Th和 237 浓缩铀溶液中的氮磷及其测定 241 溶解和离子萃取色谱分离后钚和铀遗留氧化物中的Am。 5.5 第节中提供的数据 12 使用四极ICP开发- MS。这种做法也可以应用于具有适当验证的高分辨率ICP-MS。

1.1 This practice provides guidance for an alternate linear calibration for the determination of selected actinide isotopes in appropriately prepared aqueous solutions by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). This alternate calibration is mass bias adjusted using thorium-232 ( 232 Th) and uranium-238 ( 238 U) standards. One of the benefits of this standard practice is the ability to calibrate for the analysis of highly radioactive actinides using calibration standards at much lower specific activities. Environmental laboratories may find this standard practice useful if facilities are not available to handle the highly radioactive standards of the individual actinides of interest. 1.2 The instrument response for a series of determinations of known concentration of 232 Th and 238 U defines the mass versus response relationship. For each standard concentration, the slope of the line defined by 232 Th and 238 U is used to derive linear calibration curves for each mass of interest using interference equations. The mass bias corrected calibration curves, although generated from interference equations, are specific to the instrument operating parameters and tuning in effect at the time of data acquisition. Because interference equations are part of the normal ICP-MS manufacturer's software package, this calibration methodology is widely applicable. 1.3 For this standard practice, the actinide atomic mass range that has been studied is from AMU 232 to 244. Guidance for an extended range of AMU 228 to 248 is given in this practice. 1.4 Using this practice, analyte concentrations are reported at each AMU and not by element total (that is, 239 Pu versus plutonium). 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 One of the benefits of this standard practice is the ability to calibrate for the analysis of highly radioactive actinides using calibration standards at much lower specific activities (that is, 232 Th and 238 U). Environmental laboratories may find this standard practice useful if facilities are not available to handle the highly radioactive standards of the individual actinides of interest. 5.2 The degree of actual mass bias is variable and is dependent upon instrument tune parameters. This standard practice uses universal interference equations to derive a mass bias correction that is specific to the instrument parameters and tune used for sample data acquisition and not based on a historical average. 5.3 Mass bias correction uses the instrument software interference equations and does not require additional subsequent off-line calculations. 5.4 The methodology that this standard practice is based on has been used for the determination of 232 Th and 237 Np in enriched uranium solutions and the determination of 241 Am in plutonium and uranium legacy oxides following dissolution and ion extraction chromatography separation. 5.5 Data presented in Section 12 were developed using a quadrupole ICP-MS. This practice can also be applied to high resolution ICP-MS with appropriate validation.