1.1 本规程建立了一个统一的标准，用于计算与以下各项相关的实验室内定量估计: Z %相对标准偏差（此处称为WQE Z % )，并提供有关适当使用和应用的指导。 1.2 WQE公司 Z % 计算得出的是从实验室进行的单个测量将具有估计值的最低浓度 Z %相对标准差( Z %RSD，基于实验室内标准偏差），其中 Z 通常是10的整数倍，例如10、20或30。 Z 可以小于10但不超过30。 WQE 10% 与Currie的定量方法一致 ( 1. ) 2. 和Oppenheimer等人。 ( 2. ) . 1.3 WQE的基本假设是，测试的介质、测试的浓度和开发研究数据时遵循的方案提供了对测试方法范围和适用性的代表性和公平评估，如书面所示。正确应用WQE程序可确保WQE值具有以下属性: 1.3.1 常规可实现的WQE值- 实验室应能够以合理的成本，使用实验室的标准测量系统，在常规分析中获得WQE。 为了使定量限在实际情况下可行，需要该特性。WQE计算中必须使用代表性数据。 1.3.2 常规误差源的核算- WQE应实际包括测量过程和测量材料常见的偏差和变化源。这些来源包括但不限于固有仪器噪声、一些典型的携带误差、装瓶、保存、样品处理和储存、分析员、样品制备、仪器和基质。 1.3.3 排除可避免的误差源- WQE应现实地排除可避免的偏差和变化来源（即在常规样本测量中可以合理避免的来源）。可避免的来源包括但不限于对样品的修改、对测量程序的修改、对经验证方法的测量设备的修改，以及严重且易于识别的转录错误（前提是有一种方法可以在样品的常规处理中检测、纠正或消除这些错误）。 1.4 WQE适用于相对于其他来源仪器校准误差较小的测量方法，因为该实践没有建模或解释仪器校准误差，通常大多数定量估计都是如此。 因此，当主要变化源不是仪器校准，而是以下一个或多个因素时，WQE程序是合适的: 1.4.1 样品制备， 尤其是当校准标准不经过样品制备时。 1.4.2 分析师的分歧， 尤其是当分析员几乎没有机会影响仪器校准结果时（例如自动校准）。 1.4.3 仪器（测量设备）的差异， 例如制造商、型号、硬件、电子学、采样率、化学处理率、积分时间、软件算法、内部信号处理和阈值、有效样本量和污染水平的差异。 1.5 数据质量目标- 对于给定方法，通常会计算数据集产生可靠估计的最低RSD的WQE。因此，如果可能，WQE 10 % 将进行计算。如果数据表明该方法噪声太大，则WQE 10 % 无法可靠计算，可能必须计算WQE 20 % ，或者可能是WQE 30 % . 在任何情况下，具有更高 RSD水平（如WQE 50 % )尽管RSD<10的WQE不会被考虑 % （如WQE 5. % )可以接受。适当水平的 RSD基于特定用途的数据质量目标。 这种做法允许在用户选择的情况下计算WQE RSD小于30 %. 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 本规程的适当应用应导致实验室在将测试方法/基质/分析物组合应用于常规样品分析时实现WQE。 也就是说，实验室应能够测量大于WQE的浓度 Z % ，相关RSD等于 Z %或更少。 5.2 WQE值可用于比较不同方法的定量能力，以在同一实验室内分析同一基质中的同一分析物。 5.3 WQE程序应用于建立实验室内定量能力，以便在定量对数据使用很重要的实验室中应用方法。WQE的目的不是施加报告限制。其目的是提供一个可靠的程序来确定方法的定量特征（如在实验室中对基质和分析物实施的），从而为实验室提供表征所产生任何数据中不确定性的可靠信息。 然后，实验室可以就审查数据做出明智的决定，并拥有必要的信息，以提供报告数据不确定性的可靠估计。

1.1 This practice establishes a uniform standard for computing the within-laboratory quantitation estimate associated with Z % relative standard deviation (referred to herein as WQE Z % ), and provides guidance concerning the appropriate use and application. 1.2 WQE Z % is computed to be the lowest concentration for which a single measurement from the laboratory will have an estimated Z % relative standard deviation ( Z % RSD, based on within-laboratory standard deviation), where Z is typically an integer multiple of 10, such as 10, 20, or 30. Z can be less than 10 but not more than 30. The WQE 10 % is consistent with the quantitation approaches of Currie ( 1 ) 2 and Oppenheimer, et al. ( 2 ) . 1.3 The fundamental assumption of the WQE is that the media tested, the concentrations tested, and the protocol followed in developing the study data provide a representative and fair evaluation of the scope and applicability of the test method, as written. Properly applied, the WQE procedure ensures that the WQE value has the following properties: 1.3.1 Routinely Achievable WQE Value— The laboratory should be able to attain the WQE in routine analyses, using the laboratory’s standard measurement system(s), at reasonable cost. This property is needed for a quantitation limit to be feasible in practical situations. Representative data must be used in the calculation of the WQE. 1.3.2 Accounting for Routine Sources of Error— The WQE should realistically include sources of bias and variation that are common to the measurement process and the measured materials. These sources include, but are not limited to intrinsic instrument noise, some typical amount of carryover error, bottling, preservation, sample handling and storage, analysts, sample preparation, instruments, and matrix. 1.3.3 Avoidable Sources of Error Excluded— The WQE should realistically exclude avoidable sources of bias and variation (that is, those sources that can reasonably be avoided in routine sample measurements). Avoidable sources include, but are not limited to, modifications to the sample, modifications to the measurement procedure, modifications to the measurement equipment of the validated method, and gross and easily discernible transcription errors (provided there is a way to detect and either correct or eliminate these errors in routine processing of samples). 1.4 The WQE applies to measurement methods for which instrument calibration error is minor relative to other sources, because this practice does not model or account for instrument calibration error, as is true of most quantitation estimates in general. Therefore, the WQE procedure is appropriate when the dominant source of variation is not instrument calibration, but is perhaps one or more of the following: 1.4.1 Sample Preparation, and especially when calibration standards do not go through sample preparation. 1.4.2 Differences in Analysts, and especially when analysts have little opportunity to affect instrument calibration results (as is the case with automated calibration). 1.4.3 Differences in Instruments (measurement equipment), such as differences in manufacturer, model, hardware, electronics, sampling rate, chemical-processing rate, integration time, software algorithms, internal signal processing and thresholds, effective sample volume, and contamination level. 1.5 Data Quality Objectives— For a given method, one typically would compute the WQE for the lowest RSD for which the data set produces a reliable estimate. Thus, if possible, WQE 10 % would be computed. If the data indicated that the method was too noisy, so that WQE 10 % could not be computed reliably, one might have to compute instead WQE 20 % , or possibly WQE 30 % . In any case, a WQE with a higher RSD level (such as WQE 50 % ) would not be considered, though a WQE with RSD < 10 % (such as WQE 5 % ) could be acceptable. The appropriate level of  RSD is based on the data quality objective(s) for a particular use or uses. This practice allows for calculation of WQEs with user selected  RSDs less than 30 %. 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 Appropriate application of this practice should result in a WQE achievable by the laboratory in applying the tested method/matrix/analyte combination to routine sample analysis. That is, a laboratory should be capable of measuring concentrations greater than WQE Z % , with the associated RSD equal to Z % or less. 5.2 The WQE values may be used to compare the quantitation capability of different methods for analysis of the same analyte in the same matrix within the same laboratory. 5.3 The WQE procedure should be used to establish the within-laboratory quantitation capability for any application of a method in the laboratory where quantitation is important to data use. The intent of the WQE is not to impose reporting limits. The intent is to provide a reliable procedure for establishing the quantitative characteristics of the method (as implemented in the laboratory for the matrix and analyte) and thus to provide the laboratory with reliable information characterizing the uncertainty in any data produced. Then the laboratory can make informed decisions about censoring data and has the information necessary for providing reliable estimates of uncertainty with reported data.