title: Development and GC-MS validation of a highly sensitive recombinant G6PDH-based homogeneous immunoassay for the detection of buprenorphine and norbuprenorphine in urine.
abstract: 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 mg), 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 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 1 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.
authors.affiliation: Immunalysis Corporation, 829 Towne Center Drive, Pomona, California 91767, USA.
authors.forename: Guohong
authors.initials: G
authors.lastname: Wang
authors.forename: Michael
authors.initials: M
authors.lastname: Vincent
authors.forename: Warren
authors.initials: W
authors.lastname: Rodrigues
authors.forename: Alpana
authors.initials: A
authors.lastname: Agrawal
authors.forename: Christine
authors.initials: C
authors.lastname: Moore
authors.forename: Rekha
authors.initials: R
authors.lastname: Barhate
authors.forename: E
authors.initials: E
authors.lastname: Abolencia
authors.forename: Cynthia
authors.initials: C
authors.lastname: Coulter
authors.forename: James
authors.initials: J
authors.lastname: Soares
authors.forename: Yi-Feng
authors.initials: YF
authors.lastname: Zheng
authors.forename: Celeste
authors.initials: C
authors.lastname: Taylor
authors.forename: Nihmat
authors.initials: N
authors.lastname: Morjana
mesh_terms: D000701:Analgesics, Opioid / Q000627:therapeutic use / Q000652:urine*; D002047:Buprenorphine / Q000031:analogs & derivatives* / Q000627:therapeutic use / Q000652:urine*; D003429:Cross Reactions; D017248:Enzyme Multiplied Immunoassay Technique; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D005954:Glucosephosphate Dehydrogenase; D006556:Heroin Dependence / Q000188:drug therapy; D006801:Humans; D011994:Recombinant Proteins; D015203:Reproducibility of Results; D015813:Substance Abuse Detection / Q000379:methods
chemical_list: D000701:Analgesics, Opioid; D011994:Recombinant Proteins; D002047:Buprenorphine; C043585:norbuprenorphine; D005954:Glucosephosphate Dehydrogenase