Development and GC-MS Validation of a Highly Sensitive Recombinant G6PDH-Based Homogeneous Immunoassay for the Detection of Buprenorphine and Norbuprenorphine in Urine
Journal of Analytical Toxicology
L Abstract J Buprenorphine is now increasingly prescribed as an alternative to methadone for the treatment of heroin addiction. Because of its potency (dosage usages from 0.2 mg to 8 rag), the drug concentrations in body fluids are normally very low. Here, we report the first recombinant glucose-6-phosphate dehydrogenase (G6PDH)-based homogeneous immunoassay (EMIT-type assay) for free buprenorphine and free norbuprenorphine in urine. The antibody used in this assay cross-reacts nearly
... ts nearly identically with buprenorphine and norbuprenorphine and, at the same time, has less than 1% cross-reactivity with a wide range of commonly prescribed opiates, particularly those structurally related compounds such as morphine, codeine, and dihydrocodeine. More importantly, this assay has a low detection limit of I ng/mL for buprenorphine or norbuprenorphine. Further evaluation of this technique using gas chromatography-mass spectrometry (GC-MS) of authentic urine samples demonstrated that the accuracy of the assay is greater than 95 %. Because this assay is designed to measure the free drugs in urine, it resulted in simplification for GC-MS or liquid chromatography-MS confirmation methods that did not require urine hydrolysis before solid-phase or liquid-liquid extraction. * This recombinant G6PDH-based immunoassay is under development and not available for sale. Reproduction (photocopying) of editorial content of this journal is prohibited without publisher's permission.