1.1 有毒元素可能存在于环境水中，并可能通过植物和动物的吸收进入食物链；有毒金属的实际浓度通常低于纳克/毫升。美国环保局已在《美国联邦公报》40 CFR中公布了其水质标准 131.36，水质标准提交的最低要求，第一章（7-1-00版），见附件， 表A1.1 . 美国环境保护局还制定了方法1640，以满足这些要求，见附件， 表A1.2 . 1.2 电感耦合等离子体质谱（ICP-MS）是一种具有足够灵敏度的技术，可常规测量淡水和盐水中的有毒元素（试验方法 D5673 ). 然而，盐水和硬水基质对ICP-MS在所需亚纳克/毫升水平下进行直接多元素分析提出了分析挑战。 1.3 本规程描述了一种用于制备水样的方法，以便使用ICP进行后续多元素分析- MS.本规程适用于可过滤或消化的海水和淡水基质。采用本方法制备的样品已通过ICP-MS对附件中列出的元素进行了分析， 表A1.3 ). 1.4 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。 1.5 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。 1.6 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 周围海水中通常含有极低浓度的有毒金属，需要敏感的分析方法（如ICP-MS）来检测和测量金属浓度。 5.2 由于海水中存在高溶解盐浓度，需要对样品进行预处理，以消除信号抑制和由于基质而产生的显著多原子干扰，这两种干扰都会降低检测限。

1.1 Toxic elements may be present in ambient waters and may enter the food chain via uptake by plants and animals; the actual concentrations of toxic metals are usually sub-ng/mL. The U.S. EPA has published its Water Quality Standards in the U.S. Federal Register 40 CFR 131.36, Minimum requirements for water quality standards submission, Ch. I (7-1-00 Edition), see Annex, Table A1.1 . The U.S. EPA has also developed Method 1640 to meet these requirements, see Annex, Table A1.2 . 1.2 Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) is a technique with sufficient sensitivity to routinely measure toxic elements in ambient waters, both fresh and saline (Test Method D5673 ). However saline and hard water matrices pose analytical challenges for direct multielement analysis by ICP-MS at the required sub-ng/mL levels. 1.3 This practice describes a method used to prepare water samples for subsequent multielement analysis using ICP-MS. The practice is applicable to seawater and fresh water matrices, which may be filtered or digested. Samples prepared by this method have been analyzed by ICP-MS for the elements listed in Annex, Table A1.3 ). 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.5 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. 1.6 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 Ambient marine waters generally contain very low concentrations of toxic metals that require sensitive analytical methods, such as ICP-MS, to detect and measure the metal's concentrations. 5.2 Due to the high dissolved salt concentrations present in seawater, sample pretreatment is required to remove signal suppression and significant polyatomic interferences due to the matrix both of which compromise detection limits.