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Publications (8)12.84 Total impact

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    ABSTRACT: The objective of this preliminary study was to identify and quantify potential nicotine (NIC) biomarkers in post-exposure oral fluid samples collected from 10 NIC-abstinent human participants administered 7 mg transdermal NIC using liquid chromatography-tandem mass spectrometry (LC-MS-MS). Oral fluid samples were collected prior to NIC patch application and at 0.5 and 0.75 h after patch removal using the Quantisal() oral fluid collection device. The validated LC-MS-MS analyte panel included nicotine-Nbeta-D-glucuronide, cotinine-N-oxide, trans-3-hydroxycotinine, norcotinine, trans-nicotine-1'-N-oxide, cotinine (COT), nornicotine, NIC, anatabine, anabasine, and cotinine-N-beta-D-glucuronide. Analytes and corresponding deuterated internal standards were extracted by solid-phase extraction. NIC and COT concentrations were quantifiable in oral fluid samples collected from 6 of the 10 participants 0.5 h after patch removal and in oral fluid samples collected from 7 of the 10 participants 0.75 h after patch removal. Based on the mean NIC and COT concentrations in oral fluid and plasma for the participants with both quantifiable NIC and COT at the 0.5 and 0.75 h collection times, the oral fluid-plasma ratio was 6.4 for NIC and 3.3 for COT. An ELISA procedure was also validated and successfully applied as a screening tool for these oral fluid samples in conjunction with LC-MS-MS confirmation. An ELISA cut-off concentration of 5.0 ng/mL provided excellent sensitivity for discrimination of COT-positive post-exposure oral fluid samples collected after low-level transdermal NIC exposure and oral fluid samples collected prior to patch application.
    Journal of analytical toxicology 09/2010; 34(7):357-66. · 2.11 Impact Factor
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    ABSTRACT: The development of a highly sensitive enzyme-linked immunosorbent assay and gas chromatography-mass spectrometry confirmation method for the detection of dextromethorphan and its major metabolite dextrorphan in urine and oral fluid is described. For the screening assay, the intraday precision was less than 8% for urine and less than 5% for oral fluid. The interday precision was less than 10% for both drugs in urine and oral fluid. For the confirmatory procedure, both inter- and intraday precision was less than 5% for both matrices. The detection limit for both methods was 1 ng/mL. The quantifying ions chosen from the full scan mass spectra were m/z 271 for dextromethorphan, m/z 329 for dextrorphan, and m/z 332 for tri-deuterated dextrorphan-d(3). A high recovery yield (> 93%) from the Quantisal oral fluid collection device was achieved, and the drugs were stable in the collection device for at least 10 days at room temperature. The extracted drugs from both matrices were stable for at least 48 h while kept at room temperature. Both screening and confirmatory procedures were applied to authentic urine and oral fluid specimens obtained from volunteers following therapeutic ingestion of dextromethorphan.
    Journal of analytical toxicology 04/2008; 32(3):220-6. · 2.11 Impact Factor
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    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.
    Journal of analytical toxicology 10/2007; 31(7):377-82. · 2.11 Impact Factor
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    ABSTRACT: This article details the stability of Delta(9)-tetrahydrocannabinol (THC) in oral fluid during collection, extraction and storage. Oral fluid is being increasingly used as the specimen of choice for the detection of drug use in various applications. Studies to determine the extraction efficiency of THC from the collection buffer and stability under various laboratory storage conditions were carried out. THC was extracted from the collection pad and buffer with an average efficiency over 80% and was stable in Quantisal oral fluid extraction buffer when stored at refrigerated temperatures. Fluorescent lighting caused THC losses of over 50%, however the presence of the pad reduced the loss. In the dark, the loss of THC at room temperature was approximately 20% over 14 days. When stored with the serum separators in place, THC losses were significant. After 3 days, THC concentration was reduced by almost 30%, and after 14 days, 60% of the drug was lost and the losses were not concentration dependent.
    Forensic Science International 01/2007; 164(2-3):126-30. · 2.31 Impact Factor
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    ABSTRACT: The determination of propoxyphene in oral fluid using solid-phase extraction and gas chromatography-mass spectrometry is described for the first time. The method employs collection of oral fluid with the Quantisal device, immunoassay screening of the specimen, confirmation of the positive screened samples after extraction using cation exchange/hydrophobic solid-phase extraction columns, optimized derivative formation, and gas chromatography-mass spectrometry in electron impact mode. Validated parameters including selectivity, linearity, accuracy, intra- and interday precision, extraction efficiency, and limit of quantitation were all within acceptable limits. The method was applied to authentic specimens taken from an individual prescribed propoxyphene following surgery.
    Journal of analytical toxicology 11/2006; 30(8):516-8. · 2.11 Impact Factor
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    ABSTRACT: The use of prescription drugs, including synthetic opiates, is increasing in the U.S., with emergency room reports showing a dramatic rise in prescription opiate abuse. As part of an ongoing study, the hair of admitted opiate users was analyzed for hydrocodone and hydromorphone, as well as codeine, morphine, and 6-acetylmorphine in order to determine if there was any correlation between self-reported frequency of opiate intake and the concentration of drug detected in hair. The hairs were confirmed using gas chromatography-mass spectrometry following screening by enzyme linked immunosorbent assay (ELISA). Twenty-four hair specimens collected from volunteers showed the presence of hydrocodone (130-15,933 pg/mg); four of those also contained hydromorphone (59-504 pg/mg). The specimens were also analyzed for morphine, codeine, and 6-acetylmorphine. Hair specimens from five self-reported codeine users showed concentrations of hydrocodone between 592 and 15,933 pg/mg. In addition, codeine was present at concentrations of 575-20,543 pg/mg, but neither morphine nor hydromorphone were present in any of those hair specimens. Though the analysis of some opiates in hair has been previously published, this is the first study where the hydrocodone and hydromorphone concentrations have been measured following self-reported opiate intake.
    Journal of analytical toxicology 07/2006; 30(6):353-9. · 2.11 Impact Factor
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    ABSTRACT: Proposed revisions to the Federal guidelines, which include the potential use of hair and oral fluid, as well as urine, for workplace drug testing were published in 2004. This study was designed to determine the positivity rate in various specimen types, both in a drug using population and a population denying cocaine use. The study enrolled 200 subjects, half of whom admitted to cocaine use, half who did not. Each subject provided a urine sample, an oral fluid and a hair specimen taken from the head at the time of interview. Information on drug use, including time of last use, frequency of use, ethnicity, age, sex and hair color were recorded for each subject. The specimens were analyzed for cocaine and/or its metabolites depending on the matrix and the data is presented. Hair identified the highest number of drug users in both the admitted using population and those who denied use. Oral fluid and urine gave similar detection rates in both populations, with oral fluid slightly better in the self-reported non-using population, and urine slightly better in the self-reported cocaine user population. This is the first study where hair, oral fluid and urine were collected simultaneously from a drug using population. Hairis the most likely matrix to identify cocaine users. Des révisions proposées aux directives fédérales incluant l'utilisation potentielle des cheveux, de la salive ainsi que des urines pour le dépistage des conduites addictives en entreprise ont été publiées en 2004. Cette étude a été conçue pour déterminer le taux de positivité de différents types d'échantillons, dans une population toxicomane et dans une autre niant sa consommation de cocaïne. Cette étude a été menée sur 200 sujets, la moitié admettant une consommation de cocaïne, l'autre moitié la niant. Chaque sujet a donné un échantillon d'urine, de salive et de cheveux prélevés au moment de l'entrevue. Pour chaque sujet, des informations sur leur consommation de stupéfiants, incluant le moment de la dernière prise et la fréquence de consommation, leur appartenance ethnique, leur âge, leur sexe et la couleur de leurs cheveux ont été enregistrés. Les échantillons ont été analysés pour la cocaïne et/ou ses metabolites selon la matrice. Les résultats sont présentés ci-dessous. Les cheveux ont identifié le plus grand nombre de toxicomânes dans les deux populations. La salive et les urines ont donné des taux de détection similaires dans les deux populations, avec une meilleure détection dans la salive pour la population se disant saine et une meilleure détection dans les urines pour la population s'admettant consommatrice de cocaïne. C'est la première étude où des cheveux, de la salive et des urines ont été collectés simultanément sur une population toxicomane. Le cheveu est la matrice la plus appropriée pour identifier des consommateurs de cocaïne.
    http://dx.doi.org/10.1051/ata:2005003. 01/2005;
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    ABSTRACT: Proposed revisions to the Federal guidelines, which include the potential use of hair and oral fluid, as well as urine, for workplace drug testing were published in the Federal Register in 2004. This study was designed to determine the positivity rate in various specimen types, both in a drug using population and a population denying methamphetamine use. The study enrolled 200 subjects, half of whom admitted to methamphetamine use, halfwho did not. Each subject provided a urine sample, an oral fluid and a hair specimen taken from the head at the time of interview. Information on drug use, including time of last use, frequency of use, ethnicity, age, sex and hair color were recordedfor each subject. The hair specimens were analyzed for methamphetamine, amphetamine, 3-4 methylenedioxy-methamphetamine (MDMA), its metabolite methylenedioxy-amphetamine (MDA) and methylenedioxy ethylamphetamine (MDEA). The oral fluid specimens were confirmedfor the presence of methamphetamine, amphetamine, MDMA and MDA. Hair identified the highest number of drug users in both the admitted using population and those who denied use. Urine identified a higher number of positive subjects than oral fluid. While the analysis of amphetamines in hair, oral fluid and urine has been previously published, this is the first study where all three matrices were collected simultaneouslyfrom a drug using population, and analyzed according to the proposed Federal guidelines. Des révisions proposées aux directives fédérales incluant l'utilisation potentielle des cheveux, de la salive ainsi que des urines pour le dépistage des conduites addictives en entreprise ont été publiés dans le registre fédéral en 2004. Cette étude a été conçue pour déterminer le taux de positivité de différents types d'échantillons dans une population toxicomane et dans une autre niant sa consommation de methamphetamine. Cette étude a été menée sur 200 sujets, la moitié admettant une consommation de methamphetamine, l'autre moitié la niant. Chaque sujet a donné un échantillon d'urine, de salive et de cheveux prélevés au moment de l'entrevue. Pour chaque sujet, des informations sur, leur consommation de stupéfiants, incluant la fréquence de consommation, leur appartenance ethnique, leur âge, leur sexe et la couleur de leurs cheveux ont été enregistrées. Les échantillons ont été analysés pour la methamphetamine, l'amphétamine, la 3-4 méthylendioxy- methamphetamine (MDMA), son metabolite la méthylendioxy-amphétamine (MDA) et la méthylendioxy éthylamphétamine (MDEA). Les échantillons de salive ont servi à valider la présence de methamphetamine, d'amphétamine, de MDMA et de MDA. Les cheveux ont identifiés le plus grand nombre de toxicomanes dans les deux populations. Les urines ont permis d'identifier un plus grand nombre de sujets positifs que la salive. Bien que l'analyse des amphétamines dans les cheveux, la salive et les urines aient déjà été publiée, c'est la première étude où les trois matrices ont été collectées simultanément sur une population toxicomane et analysées en suivant les directives fédérales.
    Annales de Toxicologie Analytique 01/2005;