作者描述了一种计算定量水平（QL）的方法，该方法不需要改变当前的实验室实践。当定义为方法检测限（MDL）浓度的两倍时，可靠检测水平（RDL）为假阳性和假阴性检测决策提供了充分的保护。当分析物浓度达到RDL时，仪器响应的相应精度足以用于分析目的。因此，RDL（由单个实验室确定）是该实验室的合理定量下限。为了确定适用于监管目的的实验室间QL，将实验室间MDL中值乘以可变因子（通常为4-7，根据实际实验室性能数据确定）。超过80%的被调查实验室的RDL小于或等于计算的QL，这表明在该水平下可以实现足够的定量，并且QL应适用于监管目的。 包括26个参考文献、表格和图表。

The authors describe an approach for calculating quantitation levels (QLs) that does not require changes in current laboratory practices. The reliable detection level (RDL), when defined as twice the concentration of the method detection limit (MDL), provides adequate protection against both false-positive and false-negative detection decisions. When analyte concentrations are at the RDL, the corresponding precision in the instrument response is adequate for analytical purposes. Therefore, the RDL (as determined by a single laboratory) is a reasonable lower limit of quantitation for that laboratory. To determine an interlaboratory QL suitable for regulatory purposes, median interlaboratory MDLs were multiplied by a variable factor (usually 4-7, determined from actual laboratory performance data). More than 80 percent of the laboratories surveyed had RDLs less than or equal to the calculated QL, indicating that adequate quantitation was attainable at this level and that the QL should be suitable for regulatory purposes. Includes 26 references, tables, figures.