Reporting limit verification (RLV): Laboratories often do not report values below a given concentration, usually called a reporting limit or minimum reporting level (MRL). These re- porting limits can be set by regulation, by the end-user of the laboratory results, or by the laboratory itself. In any case, verify with each calibration that the instrument is capable of accurately quantifying at the reporting limit. Prepare reporting limit check solution (RLCS) at the reporting limit concentration, or lower, and analyze it after calibration but before any samples are analyzed. The measured concentration of the RLCS should be within a fixed percentage of the true value, such as 50% to 150%