Certification of phencyclidine in lyophilized human urine reference materials

The National institute of Standards and Technology (formerly the National Bureau of Standards), in cooperation with the College of American Pathologists (CAP), has certified the concentrations of phencyclidine (PCP) in two new reference materials (RMs). One of these materials is Standard Reference Material (SRM) 1511, Multidrugs of Abuse in Freeze-dried Urine, and the other material is a CAP PCP RM. In order to minimize the possibility of undetected bias, two independent analytical methods, employing gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry, were used to certify PCP in these materials. Results from the two methods were in good agreement and were statistically combined to yield certified values of 23.8 ng/mL for PCP in SRM 1511 and 11.9, 23.4, and 49.5 ng/mL for three levels of PCP in the CAP RM. A round-robin study of SRM 1511 among five military laboratories demonstrated the suitability of the SRM for its intended purpose.