90.103—Maintenance of quality control records.

Quality control records pertaining, but not limited to the following areas, shall be retained by the laboratory for at least the 3 most recent years:
(a) Prepared solution standardizations;
(b) Recovery studies by known analyte additions;
(c) The purity checks of reagents and test materials;
(d) Apparatus and equipment calibrations;
(e) The quality examination and testing of materials;
(f) The mandatory participation in proficiency check sample testing or collaborative studies;
(g) Daily critical parameter checks of equipment, such as temperature readings;
(h) The equivalency tests of new procedures with standard methodologies.