The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Christine Moore - One of the best experts on this subject based on the ideXlab platform.
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determination of cocaine Benzoylecgonine cocaethylene and norcocaine in human hair using solid phase extraction and liquid chromatography with tandem mass spectrometric detection
Journal of Chromatography B, 2007Co-Authors: Christine Moore, Cynthia Coulter, Katherine CromptonAbstract:Abstract A quantitative analytical procedure for the determination of cocaine, Benzoylecgonine and cocaethylene and norcocaine in hair has been developed and validated. The hair samples were washed, incubated, and any drugs present were quantified using mixed mode solid-phase extraction and liquid chromatography with tandem mass spectrometric detection in positive atmospheric pressure chemical ionization mode. For confirmation, two transitions were monitored and one ion ratio was determined, which was within 20% of that of the known calibration standards. The monitoring of the qualifying transition and requirement for its presence within a specific ratio to the primary ion limited the sensitivity of the assay, particularly for Benzoylecgonine, however, the additional confidence in the final result as well as forensic defensibility were considered to be of greater importance. Even with simultaneous monitoring, the concentrations proposed by the United States Federal guidelines for hair analysis were achieved. The limits of quantitation were 50 pg/mg; the limit of detection was 25 pg/mg. The intra-day precision of the assays at 100 pg/mg ( n = 5) was 1.3%, 8.1%, 0.8% and 0.4%; inter-day precision 4.8%, 9.2%, 15.7% and 12.6% ( n = 10) for cocaine, Benzoylecgonine, cocaethylene and norcocaine, respectively. The methods were applied to both proficiency specimens and to samples obtained during research studies in the USA.
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determination of cocaine and its major metabolite Benzoylecgonine in amniotic fluid umbilical cord blood umbilical cord tissue and neonatal urine a case study
Journal of Analytical Toxicology, 1993Co-Authors: Christine Moore, S Brown, Adam Negrusz, Ian R Tebbett, W Meyer, L JainAbstract:The determination of cocaine abuse among pregnant women has become a topical issue for both legal and emotional reasons. The analysis of urine from both mother and baby using immunoassay procedures is the most common method of determining the presence of cocaine and its metabolites. However, unless exposure to cocaine has occurred recently, false negatives are frequently obtained from the analysis of neonatal urine (1). More recently, meconium has been used to determine cocaine abuse. Because meconium is cumulative throughout the pregnancy after about 16 weeks, it has been suggested that it may be a more accurate sample for determining cocaine use than the more commonly used urine (2,3). Amniotic fluid, umbilical cord blood, and umbilical cord tissue have not been analyzed for cocaine and its metabolites even though they are present for the entire pregnancy. A study of the available maternal and fetal biological fluids following a premature delivery in order to determine cocaine abuse during pregnancy was carded out. The maternal urine tested positive for cocaine metabolite using immunoassay. Ease of sample collection, extraction, and determination were all considered to be important factors in sample analysis. Solid-phase extraction using XTrackT | high-flow sorbents (Worldwide Monitoring) allowed the easy extraction of amniotic fluid, homogenized umbilical cord, and umbilical cord blood. The more common Clean Screen | sorbents were used for urinalysis. The extracts were subsequently analyzed and quantitated using HPLC with multiwavelength UV detection (4,5). Results are shown in Table I. Neonatal urine showed the highest concentration of Benzoylecgonine, which is probably indicative of recent Table I. Results of HPLC Analyses Benzoylecg0nine Cocaine Sample
Iria Gonzalezmarino - One of the best experts on this subject based on the ideXlab platform.
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spatio temporal assessment of illicit drug use at large scale evidence from 7 years of international wastewater monitoring
Addiction, 2020Co-Authors: Iria Gonzalezmarino, Jose Antonio Azlomba, Nikiforos A Alygizakis, Maria Jesus Andrescosta, Richard Ade, Leo Arro, Jean Daniel Erse, Lubertus Ijlsma, Igo OdikAbstract:Background and aims Wastewater‐based epidemiology is an additional indicator of drug use that is gaining reliability to complement the current established panel of indicators. The aims of this study were to: (i) assess spatial and temporal trends of population‐normalized mass loads of Benzoylecgonine, amphetamine, methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA) in raw wastewater over 7 years (2011–17); (ii) address overall drug use by estimating the average number of combined doses consumed per day in each city; and (iii) compare these with existing prevalence and seizure data. Design Analysis of daily raw wastewater composite samples collected over 1 week per year from 2011 to 2017. Setting and Participants Catchment areas of 143 wastewater treatment plants in 120 cities in 37 countries. Measurements Parent substances (amphetamine, methamphetamine and MDMA) and the metabolites of cocaine (Benzoylecgonine) and of Δ9‐tetrahydrocannabinol (11‐nor‐9‐carboxy‐Δ9‐tetrahydrocannabinol) were measured in wastewater using liquid chromatography–tandem mass spectrometry. Daily mass loads (mg/day) were normalized to catchment population (mg/1000 people/day) and converted to the number of combined doses consumed per day. Spatial differences were assessed world‐wide, and temporal trends were discerned at European level by comparing 2011–13 drug loads versus 2014–17 loads. Findings Benzoylecgonine was the stimulant metabolite detected at higher loads in southern and western Europe, and amphetamine, MDMA and methamphetamine in East and North–Central Europe. In other continents, methamphetamine showed the highest levels in the United States and Australia and Benzoylecgonine in South America. During the reporting period, Benzoylecgonine loads increased in general across Europe, amphetamine and methamphetamine levels fluctuated and MDMA underwent an intermittent upsurge. Conclusions The analysis of wastewater to quantify drug loads provides near real‐time drug use estimates that globally correspond to prevalence and seizure data.
L Jain - One of the best experts on this subject based on the ideXlab platform.
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determination of cocaine and its major metabolite Benzoylecgonine in amniotic fluid umbilical cord blood umbilical cord tissue and neonatal urine a case study
Journal of Analytical Toxicology, 1993Co-Authors: Christine Moore, S Brown, Adam Negrusz, Ian R Tebbett, W Meyer, L JainAbstract:The determination of cocaine abuse among pregnant women has become a topical issue for both legal and emotional reasons. The analysis of urine from both mother and baby using immunoassay procedures is the most common method of determining the presence of cocaine and its metabolites. However, unless exposure to cocaine has occurred recently, false negatives are frequently obtained from the analysis of neonatal urine (1). More recently, meconium has been used to determine cocaine abuse. Because meconium is cumulative throughout the pregnancy after about 16 weeks, it has been suggested that it may be a more accurate sample for determining cocaine use than the more commonly used urine (2,3). Amniotic fluid, umbilical cord blood, and umbilical cord tissue have not been analyzed for cocaine and its metabolites even though they are present for the entire pregnancy. A study of the available maternal and fetal biological fluids following a premature delivery in order to determine cocaine abuse during pregnancy was carded out. The maternal urine tested positive for cocaine metabolite using immunoassay. Ease of sample collection, extraction, and determination were all considered to be important factors in sample analysis. Solid-phase extraction using XTrackT | high-flow sorbents (Worldwide Monitoring) allowed the easy extraction of amniotic fluid, homogenized umbilical cord, and umbilical cord blood. The more common Clean Screen | sorbents were used for urinalysis. The extracts were subsequently analyzed and quantitated using HPLC with multiwavelength UV detection (4,5). Results are shown in Table I. Neonatal urine showed the highest concentration of Benzoylecgonine, which is probably indicative of recent Table I. Results of HPLC Analyses Benzoylecg0nine Cocaine Sample
Ovandir Alves Silva - One of the best experts on this subject based on the ideXlab platform.
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determination of cocaine Benzoylecgonine and cocaethylene in human hair by solid phase microextraction and gas chromatography mass spectrometry
Journal of Chromatography B, 2003Co-Authors: Fernanda Crossi Pereira De Toledo, Mauricio Yonamine, Regina Lúcia De Moraes Moreau, Ovandir Alves SilvaAbstract:The present work describes a highly precise and sensitive method developed to detect cocaine (COC), Benzoylecgonine (BE, its main metabolite) and cocaethylene (CE, transesterification product of the coingestion of COC with ethanol) in human head hair samples. The method was based on an alkylchloroformate derivatization of Benzoylecgonine and the extraction of the analytes by solid-phase microextraction (SPME). Gas chromatography-mass spectrometry (GC-MS) was used to identify and quantify the analytes in selected ion monitoring mode (SIM). The limits of quantification and detection (LOQ and LOD) were: 0.1 ng/mg for COC and CE, and 0.5 ng/mg for BE. Good inter- and intra-assay precision was observed. The dynamic range of the assay was 0.1-50 ng/mg. The method is not time consuming and was shown to be easy to perform.
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Determination of cocaine, Benzoylecgonine and cocaethylene in human hair by solid-phase microextraction and gas chromatography–mass spectrometry
Journal of Chromatography B, 2003Co-Authors: Fernanda Crossi Pereira De Toledo, Mauricio Yonamine, Regina Lúcia De Moraes Moreau, Ovandir Alves SilvaAbstract:The present work describes a highly precise and sensitive method developed to detect cocaine (COC), Benzoylecgonine (BE, its main metabolite) and cocaethylene (CE, transesterification product of the coingestion of COC with ethanol) in human head hair samples. The method was based on an alkylchloroformate derivatization of Benzoylecgonine and the extraction of the analytes by solid-phase microextraction (SPME). Gas chromatography-mass spectrometry (GC-MS) was used to identify and quantify the analytes in selected ion monitoring mode (SIM). The limits of quantification and detection (LOQ and LOD) were: 0.1 ng/mg for COC and CE, and 0.5 ng/mg for BE. Good inter- and intra-assay precision was observed. The dynamic range of the assay was 0.1-50 ng/mg. The method is not time consuming and was shown to be easy to perform.
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Confirmation of cocaine exposure by gas chromatography-mass spectrometry of urine extracts after methylation of Benzoylecgonine.
Journal of Chromatography B, 2002Co-Authors: Mauricio Yonamine, Ovandir Alves SilvaAbstract:Volatility and thermal stability are necessary physical-chemical properties for analysing a substance by gas chromatography. A derivatization step is required before gas chromatography of Benzoylecgonine (the main metabolite of cocaine). In the literature, reactions such as silylation, perfluoroalkylation or alkylation are the most frequently used to derivatize Benzoylecgonine. However, they allow the formation of products sensitive to moisture or require a purification step. So, a procedure to derivatize Benzoylecgonine with diazomethane before gas chromatographic analysis was evaluated. A study was performed to evaluate the efficiency of conversion of Benzoylecgonine in cocaine, the necessary time for reaction and the stability of ethereal solution of diazomethane. The reaction was shown to be very fast in mild conditions and there was no need for a further purification step. When Benzoylecgonine was extracted from urine by solid-phase extraction and derivatized with diazomethane, concentrations as low as 25 ng/ml could be detected using GC-MS in the full scan mode.
Katherine Crompton - One of the best experts on this subject based on the ideXlab platform.
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determination of cocaine Benzoylecgonine cocaethylene and norcocaine in human hair using solid phase extraction and liquid chromatography with tandem mass spectrometric detection
Journal of Chromatography B, 2007Co-Authors: Christine Moore, Cynthia Coulter, Katherine CromptonAbstract:Abstract A quantitative analytical procedure for the determination of cocaine, Benzoylecgonine and cocaethylene and norcocaine in hair has been developed and validated. The hair samples were washed, incubated, and any drugs present were quantified using mixed mode solid-phase extraction and liquid chromatography with tandem mass spectrometric detection in positive atmospheric pressure chemical ionization mode. For confirmation, two transitions were monitored and one ion ratio was determined, which was within 20% of that of the known calibration standards. The monitoring of the qualifying transition and requirement for its presence within a specific ratio to the primary ion limited the sensitivity of the assay, particularly for Benzoylecgonine, however, the additional confidence in the final result as well as forensic defensibility were considered to be of greater importance. Even with simultaneous monitoring, the concentrations proposed by the United States Federal guidelines for hair analysis were achieved. The limits of quantitation were 50 pg/mg; the limit of detection was 25 pg/mg. The intra-day precision of the assays at 100 pg/mg ( n = 5) was 1.3%, 8.1%, 0.8% and 0.4%; inter-day precision 4.8%, 9.2%, 15.7% and 12.6% ( n = 10) for cocaine, Benzoylecgonine, cocaethylene and norcocaine, respectively. The methods were applied to both proficiency specimens and to samples obtained during research studies in the USA.
