1.1 本规程涵盖了在收集和保存水样后，在不显著影响分析准确性的情况下，估计水样可以存储的时间段的方法。 1.2 最大保持时间取决于所使用的基质和特定分析物。因此，必须测试特定来源的水样，以确定通过标准保存实践保持样品完整性的时间段。 1.3 如果无法在采集时立即分析样本，本规程不提供有关感兴趣成分降解或从样本采集到初始分析期间可能发生的基质变化的信息。 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 为了获得有意义的分析数据，样品保存技术必须从样品采集到分析期间有效。实验室必须确认在样品采集和分析之间的最长时间内保持样品完整性。在许多情况下，了解最大保持时间很有用。对保存时间的评估也有助于判断各种保存技术的效果。

1.1 This practice covers the means of estimating the period of time during which a water sample can be stored after collection and preservation without significantly affecting the accuracy of analysis. 1.2 The maximum holding time is dependent upon the matrix used and the specific analyte of interest. Therefore, water samples from a specific source must be tested to determine the period of time that sample integrity is maintained by standard preservation practices. 1.3 In the event that it is not possible to analyze the sample immediately at the time of collection, this practice does not provide information regarding degradation of the constituent of interest or changes in the matrix that may occur from the time of sample collection to the time of the initial analysis. 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 In order to obtain meaningful analytical data, sample preservation techniques must be effective from the time of sample collection to the time of analysis. A laboratory must confirm that sample integrity is maintained throughout maximum time periods between sample collection and analysis. In many cases, it is useful to know the maximum holding time. An evaluation of holding time is useful also in judging the efficacy of various preservation techniques.