title: Comparison of the serum barbiturate fluorescence polarization immunoassay by the COBAS INTEGRA to a GC/MS method.
abstract: The authors evaluated a new Cassette Serum Barbiturates fluorescence polarization immunoassay (FPIA) on the COBAS INTEGRA. The assay was calibrated with secobarbital standards at 0, 0.5, and 4.0 microg/mL. The assay range was 0.030 to 80 microg/mL using an automatic 1/20 postdilution feature. Precision was established for two COBAS INTEGRA instruments for ten days by assaying secobarbital target concentrations ranging from 0.125 to 2.2 microg/mL. The coefficients of variation (CV) for the above target concentrations for the first instrument ranged from 2.7% to 8.3%, and for a second instrument, 3.8 to 8.3%. Seven clinically elevated bilirubin samples were spiked with 0.46 and 1.77 microg/mL secobarbital. Bilirubin interference was less than 10.9 and less than 7.9%, respectively. The average recovery ranged from 85% to 94%. The mean difference in recovery in serum versus plasma was < or = 3%. Fifty-two clinical samples were analyzed for butalbital, pentobarbital, secobarbital, and phenobarbital by GC/MS, and the results were compared to the new Cassette Serum Barbiturates FPIA. The diagnostic sensitivity and specificity were 95% and 100%, respectively. Both FPIA and GC/MS assays are clinically efficacious for monitoring serum barbiturates.
authors.affiliation: Office of the Milwaukee County Medical Examiner and the Department of Pathology, Medical College of Wisconsin, 53233, USA.
authors.forename: R D
authors.initials: RD
authors.lastname: Cannon
authors.forename: S H
authors.initials: SH
authors.lastname: Wong
authors.forename: S B
authors.initials: SB
authors.lastname: Gock
authors.forename: J J
authors.initials: JJ
authors.lastname: Jentzen
mesh_terms: D001463:Barbiturates / Q000097:blood*; D001663:Bilirubin / Q000737:chemistry; D016231:Fluorescence Polarization Immunoassay / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D006993:Hypnotics and Sedatives / Q000097:blood*; D010424:Pentobarbital / Q000097:blood; D010634:Phenobarbital / Q000097:blood; D015203:Reproducibility of Results; D012631:Secobarbital / Q000097:blood; D012680:Sensitivity and Specificity
chemical_list: D001463:Barbiturates; D006993:Hypnotics and Sedatives; D012631:Secobarbital; D010424:Pentobarbital; C004470:butalbital; D001663:Bilirubin; D010634:Phenobarbital