Is it permissible to group continuing calibration verification samples (CCVs) from a variety of batches?
EDQW Response: Box #56 states, “When the methods specify that CCVs shall be run at specific sample intervals (for example, every 10 samples), the count of these samples shall be of field samples only. However, QC samples must be run with their associated batches. The grouping of QC samples from a variety of batches is not an acceptable practice.” While CCVs are not considered batch QC, they should not be grouped together with other CCVs. The intent of the language in the box is to reiterate that QC samples such as LCS, method blank, or MS/MSD are run with their associated batch not “grouped” together in the analytical run.
