Bovine blood quality control material for cadmium, mercury, and lead

A protocol is elaborated for the preparation and characterization of a quality control material (QCM) containing intrinsic concentration of cadmium (Cd) (0.8 microgram/L) and lead (Pb) (13.4 micrograms/dL) from bovine blood and an elevated QCM containing Cd (5.0 micrograms/L), mercury (Hg) (11.2 micrograms/L), and Pb (34.5 micrograms/dL) from bovine blood spiked with aqueous spiking-solutions prepared with salts of Cd, Hg, and Pb. Borosilicate glass septum vials of 7-mL capacity were filled with 5 mL of blood, sealed with Teflon-silicone discs and plastic screw caps, and stored at -20 degrees C. Quality control, intervial and intravial, and storage stability values for Cd, Hg, and Pb were ascertained by analyzing the blood in randomly selected vials by an internal laboratory using modified published methods which were established for detection limit, accuracy, and precision. Validation of the protocol was demonstrated by intravial and intervial homogenity for Cd, Hg, and Pb and no change occurred in the concentrations of the elements in bovine blood containing EDTA at storage temperatures of 4 degrees C and -20 degrees C for 2 years.