Quiroz Garduño Luis Daniel, Mora García Tania Daniela, Domínguez Adrián Sosa, Valle Moya Edith, Martínez Ríos Francisco Javier, Del Rocío Arvizu Torres María, Amezcua Vergara Mariana, Hernández Leos Rosalba, Hernández Rodríguez Carlos, Pérez García M Rosalina, de Jesús Pérez Bueno José
Centro Universitario, Facultad de Química, Universidad Autónoma de Querétaro (UAQ), Cerro de las Campanas S/N, C.P. 76010, Santiago de Querétaro, Querétaro, Mexico.
Centro Nacional de Metrología (CENAM), Km. 4.5 Carretera de los Cués Mpio, C.P. 76246, Del Marqués, Querétaro, Mexico.
Sci Rep. 2024 Sep 5;14(1):20753. doi: 10.1038/s41598-024-71799-0.
Currently, there are no national and international certified reference materials (CRM) in lithium clays that can make reliable and traceable lithium measurements for the International System of Units (SI). Hence, it is necessary to have references to meet the needs in terms of mining and activities that involve the use of lithium to favor the economy derived from its multiple uses and associated benefits in the exploration, exploitation, and handling of lithium ore. In this study, a candidate for reference material (RM) of Li in clays was developed and certified based on the provisions of ISO 17034:2016 and ISO Guide 35:2017. Different mass sizes of the RM (0.05, 0.1, and 0.25 g) were used to evaluate homogeneity. An isochronous study (short-term stability) was carried out in the assessment of stability, influenced by the effects of transport at different temperatures (20, 40, and 50 °C) for a determined time of 6 weeks, in addition to a classic (long-term) study for 19 weeks. The sample was treated using microwave-assisted acid digestion and Li measurements were performed using the analytical technique of Flame Atomic Absorption Spectrometry (FAAS). The CRM is homogeneous for the sample mass sizes of 0.05 and 0.1 g, and the mass fraction of w(Li) was stable in the RM for temperatures of 20, 40, and 50 °C. The determined period of validity was 3 years.
目前，锂黏土中尚无国家和国际认证参考物质（CRM）可用于对国际单位制（SI）进行可靠且可溯源的锂测量。因此，有必要拥有参考物质，以满足采矿及涉及锂使用的活动需求，从而促进源于锂在锂矿石勘探、开采和处理中的多种用途及相关益处的经济发展。在本研究中，依据ISO 17034:2016和ISO Guide 35:2017的规定，开发并认证了一种黏土中锂参考物质（RM）的候选物。使用不同质量大小的RM（0.05、0.1和0.25 g）来评估均匀性。在稳定性评估中，除了进行为期19周的经典（长期）研究外，还进行了等时性研究（短期稳定性），研究在不同温度（20、40和50°C）下运输6周的影响对稳定性的影响。样品采用微波辅助酸消解处理，并使用火焰原子吸收光谱法（FAAS）分析技术进行锂测量。对于0.05和0.1 g的样品质量大小，CRM是均匀的，并且在20、40和50°C的温度下，RM中w(Li)的质量分数是稳定的。确定的有效期为3年。
