Validation of the Immunalysis® Microplate ELISA for the Detection of Methamphetamine in Hair

• Published in: Journal of analytical toxicology Vol. 30; no. 6; pp. 380 - 385
• Main Authors: Han, Eunyoung, Miller, Eleanor, Lee, Juseon, Park, Yonghoon, Lim, Miae, Chung, Heesun, Wylie, Fiona M., Oliver, John S.
• Format: Journal Article
• Language: English
• Published: Niles, IL Oxford University Press 01.07.2006; Preston
• Subjects: Analysis; Biological and medical sciences; Central Nervous System Stimulants - analysis; Drug addictions; Enzyme-Linked Immunosorbent Assay - methods; Evaluation Studies as Topic; Gas Chromatography-Mass Spectrometry; General pharmacology; Hair - chemistry; Humans; Medical sciences; Methamphetamine - analysis; Pharmacology. Drug treatments; Reproducibility of Results; Substance Abuse Detection - methods; Toxicology; Amphetamine derivatives; Validation; Automation; Chemical analysis; Microtiter plate; CNS stimulant; Coupled method; Psychotropic; Metamfetamine; Sympathomimetic; Medical screening; Enzyme immunoassay; Biological material; Hair (head); Gas chromatography; Drug of abuse; Mass spectrometry; ELISA assay; Comparative study; Quantitative analysis
• ISSN: 0146-4760; 1945-2403
• DOI: 10.1093/jat/30.6.380

The object of this study was to validate the Immunalysis Methamphetamine Microplate ELISA for detecting methamphetamine in hair. Twenty-nine scalp hair samples were obtained as routine cases submitted to the National Institute of Scientific Investigation in Seoul by the police. The hair samples were washed with 0.1% sodium dodecyl sulfate, distilled water, and dichloromethane. The samples were screened using the Immunalysis Methamphetamine Microplate ELISA and confirmed using gas chromatography-mass spectrometry (GC-MS). Twenty-eight hair samples were screened and confirmed as positive for methamphetamine. For ELISA analysis, the samples were extracted by incubation in monobasic phosphate buffer for 1 h at 60°C. For GC-MS, the samples were extracted for 20h in methanol containing 1% hydrochloric acid. The methanol/acid solution was evaporated to dryness and the resulting residue was derivatized with trifluoroacetic anhydride. Methamphetamine and amphetamine were detected using selective ion monitoring (SIM) mode. The Immunalysis Methamphetamine Microplate ELISA demonstrated a sensitivity and specificity of 97% and 100%, respectively, using a cut-off concentration of 0.5 ng/mg d-methamphetamine. The ELISA kit showed 63% cross-reactivity with d,l-methamphetamine and did not cross-react to any significant extent with the licit l-methamphetamine isomer. The intra- and interassay precisions were 2.5% and 3.7%, respectively.