Evaluation of six commercial amphetamine and methamphetamine immunoassays for cross-reactivity to phenylpropanolamine and ephedrine in urine.
We evaluated six commercially available amphetamine (A) and methamphetamine (MA) immunoassays for their relative cross-reactivities to isomers of phenylpropanolamine (PPA) and ephedrine (E) in urine: Syva EMIT, Abbott fluorescence polarization (FPIA), Roche, and Diagnostic Products Corporation (DPC) radioimmunoassays for A and MA. Two stereoisomers of PPA and four stereoisomers of E were tested using (1) drug-free urine spiked at 1,000 mg/L or 100 mg/L of each compound and (2) 60 clinical urine specimens not containing A or MA but having varying amounts of PPA and/or E. Specimens responding greater than the 1-mg/L A or MA cutoff were defined as positive. All specimens spiked at 100 mg/L were negative by all immunoassays. All specimens spiked at 1,000 mg/L were positive by EMIT and negative by FPIA, Roche A, and DPC A; 1,000 mg/L/-E and d-pseudoephedrine were also positive by Roche MA and DPC MA. Three of the 60 clinical specimens tested positive by EMIT and one specimen tested positive by DPC A and DPC MA.
D'Nicuola
J
J
Division of Forensic Toxicology, Armed Forces Institute of Pathology, Washington, DC 20306-6000.
Jones
R
R
Levine
B
B
Smith
M L
ML
D000661:Amphetamine / Q000276:immunology / Q000652:urine*; D003429:Cross Reactions; D004809:Ephedrine / Q000276:immunology / Q000652:urine*; D005069:Evaluation Studies as Topic; D005189:False Positive Reactions; D016231:Fluorescence Polarization Immunoassay; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007118:Immunoassay; D007124:Immunoenzyme Techniques; D008694:Methamphetamine / Q000276:immunology / Q000652:urine*; D010665:Phenylpropanolamine / Q000276:immunology / Q000652:urine*; D011863:Radioimmunoassay; D013237:Stereoisomerism; D015813:Substance Abuse Detection
D010665:Phenylpropanolamine; D008694:Methamphetamine; D000661:Amphetamine; D004809:Ephedrine