1.1 本试验方法使用电感耦合等离子体质谱（ICP-MS）在使用微波辅助酸消化制备样品后测定大麻和大麻相关基质中的多种微量元素。本试验方法适用于对干燥植物材料、浓缩物、油、提取物、大麻酊剂和大麻相关产品中微量元素的定量。如果实验室使用Practice验证额外矩阵，则可以添加其他矩阵 第8282页 详细说明了使用经认证的参考物质（CRM）对样品制备程序和分析方法进行验证的情况，以及使用若干大麻样品的峰值回收率测试对分析方法进行的验证。 1.2 本试验方法应由在使用微波消解和ICP-MS、基质干扰及其校正或减少程序方面有经验的分析员使用，且仅应由在处理、制备和分析样品以测定大麻和大麻产品中微量元素方面受过培训的人员使用 ( 1. ) . 2. 该试验方法是使用配备有碰撞/反应池（CRC）的单四极ICP-MS开发的，该碰撞/反应室可以用氦（He）气体加压。该测试方法也可使用配备CRC技术的三重四极或“串联”质谱仪（MS/MS）ICP-MS仪器运行。ICP-MS方法考虑了多原子干扰，这是ICP-MS中最常见的光谱重叠、等压干扰和任何潜在的双电荷离子干扰（M 2+ )这可能是由于样品中存在稀土元素（REE），如REE 2+ 离子干扰会影响样品中砷（As）和硒（Se）的测量精度。 表1 列出了测试方法适用的元素以及建议的分析质量，以及一些元素的次要质量。优先有毒元素砷（As）、镉（Cd）、汞（Hg）和铅（Pb），有时也称为“四大”有毒微量元素，因其毒性而单独列出，如 5.1 . 1.3 经认证的参考材料应尽可能与大麻/植物基质匹配。如果没有客户关系管理可用和/或内部客户关系管理特征良好，则可接受内部参考材料（RM），但客户关系管理是首选。对NIST 1575a松针、NRC HEMP-1和NIST大麻样品（NIST编号尚未指定）进行分析，以验证方法偏差。RM/CRM的恢复应在80 % 当浓度高于定量限值（LOD）或在证书上提供的浓度不确定度（换算为相对不确定度百分比）内时，以较大者为准。如果未获得可接受的值，可对分析溶液重新分析一次。如果仍不符合可接受性，则重新校准并重新分析整个分析顺序和/或准备并消化新的分析部分。 1.4 多实验室验证（MLV）- 该试验方法通过四个实验室分析NRC大麻CRM、NIST大麻SRM和NIST植物对照样品（NIST 1575a松针）进行测试，每个实验室运行一个四极ICP- 毫秒。 1.5 重量稀释（重量/重量）、体积稀释（体积/体积）或两种技术的组合（重量/体积）是ICP-MS样品制备的可接受方法。 1.6 单位- 以SI单位表示的值应视为标准。本标准不包括其他计量单位。 1.7 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践，并确定监管限制的适用性。 1.8 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 在美国的许多国家和州，医疗和/或娱乐用大麻（大麻）已被合法用于成人使用 ( 5. ) 许多允许使用药用和休闲大麻的司法管辖区要求对大麻和相关产品进行测试，以确保其不受污染物的影响，特别是有毒的“四大”元素，如砷、镉、汞和铅 ( 6. ) 以及其他值得考虑的金属 ( 6. ) 这些重金属会在污染土壤中生长的植物中积累，或在制造过程中发生污染 ( 7. ) 。除了确保产品安全外，当这些产品作为营养补充剂出售时，还需要对矿物和其他微量元素进行分析，以便于标记。植物和营养补充材料的微量元素分析是一个成熟的应用 ( 8. ) 在酸性消化以分解植物样品的主要成分后，ICP- 质谱由于其多元素能力、高灵敏度、高速度、鲁棒性和宽动态范围而经常用于定量分析。 5.2 本试验方法涵盖了大麻样品消化物中多种元素的快速测定。这些元素包括优先有毒元素（As、Cd、Hg和Pb），以及一些国家所需的元素和大麻群落中感兴趣的元素（V、Cr、Cu、Zn、Sb、Ba、Se、Ag、Na、Al、K、Mn、Fe、Co、Ni、Mo、Tl、Th和U）。无论被测元素的数量如何，每个试样的测试时间约为几分钟，且大多数元素的可检测性在低至亚ppb范围内。

1.1 This test method uses inductively coupled plasma mass spectrometry (ICP-MS) to determine multiple trace elements in cannabis and cannabis-related matrices following sample preparation using microwave-assisted acid digestion. This test method is applicable to the quantification of trace levels of elements in dried plant materials, concentrates, oils, extracts, tinctures of cannabis and cannabis-related products. Other matrices may be added provided that the lab validates the extra matrices using Practice D8282 . Details are provided on the validation of both the sample preparation procedure and analytical method using certified reference materials (CRMs) and validation of the analytical method using spike recovery testing of several cannabis based samples. 1.2 This test method should be used by analysts experienced in the use of microwave digestion and ICP-MS, matrix interferences, and procedures for their correction or reduction, and should only be used by personnel trained in the handling, preparation, and analysis of samples for the determination of trace elements in cannabis and cannabis products ( 1 ) . 2 This test method was developed using a single quadrupole ICP-MS equipped with a collision/reaction cell (CRC) that can be pressurized with helium (He) gas for the removal of polyatomic interferences using kinetic energy discrimination (KED). This test method can also be run using a triple quadrupole or “tandem” mass spectrometer (MS/MS) ICP-MS instrument, which is fitted with CRC technology. The ICP-MS method accounts for polyatomic interferences, which are the most common spectral overlaps in ICP-MS, isobaric interferences, and any potential doubly-charged ion interferences (M 2+ ) that may arise from the presence of rare earth elements (REEs) in the samples, as the REE 2+ ion interferences can affect the accuracy of the measurement of arsenic (As) and selenium (Se) in the samples. Table 1 lists elements for which the test method applies along with recommended analytical masses, and secondary masses for some elements. The priority toxic elements arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb), also sometimes referred to as the “big four” toxic trace elements are listed separately because of their toxicity, as discussed in 5.1 . 1.3 Certified reference materials (CRMs) should be matrix matched as closely as possible to the cannabis/plant matrix. In-house reference materials (RMs) are acceptable if no CRM is available and/or the in-house RM is well characterized, but CRMs are preferred. NIST 1575a Pine Needles, NRC HEMP-1, and a NIST hemp sample (NIST number not assigned yet) were analyzed to verify method bias. The RM/CRMs should have a recovery between 80 % to 120 % when concentrations are above the limit of quantification (LOD) or within the concentration uncertainty (converted to percent relative uncertainty) supplied on the certificate, whichever is greater. If acceptable values are not obtained, the analytical solution may be reanalyzed once. If acceptability is still not met, recalibrate and reanalyze the entire analytical sequence and/or prepare and digest new analytical portions. 1.4 Multi-laboratory Validation (MLV)— This test method was tested by analyzing an NRC hemp CRM, a NIST hemp SRM, and a NIST plant control sample (NIST 1575a Pine Needles) by four laboratories each running a single quadrupole ICP-MS. 1.5 Gravimetric dilution (weight/weight), volumetric dilution (volume/volume), or a combination of the two techniques (weight/volume) are acceptable methods for ICP-MS sample preparation. 1.6 Units— The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard. 1.7 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. 1.8 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 Medical and/or recreational marijuana (cannabis) has been legalized for adult use in many countries and states within the USA ( 5 ) . Many jurisdictions that permit the use of medicinal and recreational marijuana require testing of cannabis and associated products to ensure safety from contaminants, especially the toxic “big four” elements such as As, Cd, Hg, and Pb ( 6 ) , and other metals worthy of consideration ( 6 ) . These heavy metals can accumulate in plants grown in polluted soils or contamination can occur during the manufacturing process ( 7 ) . In addition to ensuring product safety, the analysis of mineral and other trace elements is required for labeling purposes when these products are sold as nutritional supplements. Trace element analysis of plant and nutritional supplement materials is a well-established application ( 8 ) . Following acidic digestion to break down the plant-based samples' primary components, ICP-MS is often used for quantitative analysis because of its multi-element capability, high sensitivity, speed, robustness, and wide dynamic range. 5.2 This test method covers the rapid determination of multiple elements in cannabis sample digests. The elements include the priority toxic elements (As, Cd, Hg, and Pb), as well as elements required by some states and elements of interest in the cannabis community (V, Cr, Cu, Zn, Sb, Ba, Se, Ag, Na, Al, K, Mn, Fe, Co, Ni, Mo, Tl, Th, and U). Irrespective of the number of elements being measured, test times are approximately a few minutes per test specimen, and detectability for most elements is in the low- to sub-ppb range.