10ng/ml是MRPL，属于衡量指定实验室测试能力水平的值。实验室测定曲美他嗪的方法检测限必须低于10ng/ml。
那2.1ng/ml的A瓶实测值是可以说的通了。  
“The MRPL is the minimum concentration of a Non-Threshold Substance or a Metabolite or Marker of a
Non-Threshold Substance that Laboratories shall be able to detect (Initial Testing Procedure) and
identify (Confirmation Procedure) in routine operations.
o The MRPL is not a Threshold (T) nor is it a Limit of Detection (LOD). Adverse Analytical Findings
(AAFs) may result from concentrations below the established MRPL values;”

对于曲美他嗪，应该是属于Non-threshold substance（这部分我理解为检出即阳性，没有cut off level，未进行确认）
WADA鼓励各个实验室把这类物质的检测浓度水平搞得越低越好。
"[Comment: It is recognized that some Laboratories will be able to identify and report these Non-Threshold Substances in lower concentrations than other Laboratories. While such individual capabilities are encouraged in order to improve the overall system, it is also recognized that there are minimum routine detection capabilities (defined by the applicable MRPLs) at which all Laboratories shall operate.] "

所以，美帝就是用技术霸权（最顶流的分析仪器全是美帝的）搞别人。（说不定大鹅那边实验室压根检不出美帝的低浓度样品）
修订一下，俄罗斯没有WADA资质实验室。。。。。呵呵呵。。。。

https://www.wada-ama.org/sites/default/files/resources/files/td2022mrpl_v1.0_final_eng.pdf
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修改:cryingleaf FROM 101.95.128.*
FROM 101.95.128.*