Application of discriminant analysis to differentiate between incorporation of cocaine and its congeners into hair and contamination

Hoelzle, C.; Scheufler, Frank; Uhl, Michaël; Sachs, Hans; Thieme, Detlef

doi:10.1016/j.forsciint.2007.07.020

Cited by 57 publications

(38 citation statements)

References 14 publications

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“…According to Poon et al 6 our results indicate that NCOC was always absent in hair samples with COC concentrations below 3 ng/mg, showing it is not a useful marker of active COC use in the population of occasional users. In these cases, the very low or low COC levels in hair could lead to difficulties in attributing the positive result to drug intake rather than external contamination, particularly in high‐risk populations such as police officers, drug‐dependent males or their family members and individuals who are involved in illicit COC manufacturing or distribution 11, 12…”

Section: Resultsmentioning

confidence: 99%

Norcocaine and cocaethylene distribution patterns in hair samples from light, moderate, and heavy cocaine users

Gambelunghe

Rossi

Aroni

et al. 2015

Drug Testing and Analysis

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Even though hair analysis often seems to be the best choice for retrospective monitoring of cocaine intake, differentiating between incorporated cocaine and external contamination is widely debated. In this study we report results obtained in 90 hair samples from addicts. All samples were analyzed for cocaine, benzoylecgonine, norcocaine, cocaethylene, and tropococaine by gas chromatography‐mass spectrometry (GC‐MS) techniques coupled with direct immersion solid‐phase micro‐extraction. Cocaine concentrations were stratified into three classes of usage: light (0.5–3 ng/mg), moderate (3.1–10 ng/mg) and heavy (10.1–40 ng/mg). The Substance Abuse and Mental Health Services Administration cut‐off criteria for establishing active cocaine use were applied to the results. For all samples criteria were cocaine levels above 0.5 ng/mg (ranging from 1.63 to 39.29 ng/mg, mean 9.49 ng/mg), benzoylecgonine concentrations ≥ 0.05 ng/mg (ranging from 0.19 to 5.77 ng/mg, mean 1.40), and benzoylecgonine to cocaine % ratio ≥5% (from 6.43 to 26.09%). Norcocaine was present in 58.9% of samples (concentration range: 0.22–3.14 ng/mg) and was strongly predictive only of heavy cocaine use (sensitivity 100% for cocaine concentrations above 9.58 ng/mg). Twenty hair samples from moderate and heavy users tested positive for cocaethylene (concentration range: 0.22–1.98 ng/mg, mean 0.73 ng/mg). This study on hair samples with no chance of false positive cases highlights the very limited applications of testing minor cocaine metabolites for definitive proof of active cocaine consumption. © 2015 The Authors. Drug Testing and Analysis Published by John Wiley & Sons, Ltd.

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Section: Resultsmentioning

confidence: 99%

Norcocaine and cocaethylene distribution patterns in hair samples from light, moderate, and heavy cocaine users

Gambelunghe

Rossi

Aroni

et al. 2015

Drug Testing and Analysis

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show abstract

“…Previous studies have attempted to distinguished ingestion from environmental exposure by statistical discriminant analysis or concurrent examination of multiple COC metabolites and metabolite ratios found in hair [5,23]. A clear criteria has not yet emerged that will allow 100% certainty of exclusion of external contamination due in part to traces of COC metabolites, such as NCOC and cocaethylene (CE) found as contaminants in street drugs and the apparent formation of metabolites by chemical degradation processes [5,14,24,25].…”

Section: Discussionmentioning

confidence: 99%

Norcocaine in human hair as a biomarker of heavy cocaine use in a high risk population

Poon

Gareri

Walasek

et al. 2014

Forensic Science International

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“…First, discriminative analysis to differentiate the incorporation of abused drugs into hair from external contamination of the hair surface is necessary. Hoelzle et al 57) investigated the utility of discriminative analysis in differentiating between incorporation of cocaine and its congeners into hair and external contamination, when dealing with compounds that are administered by sniffing or inhalation (e.g., cocaine). The statistical discriminant analysis made a prediction for each cocainepositive hair specimen as regards the likelihood of its belonging to the group of cocaine users or being contaminated.…”

Section: Hairmentioning

confidence: 99%

Analysis of Drugs of Abuse in Biological Specimens

Saito

Kikuchi

et al. 2011

JOURNAL OF HEALTH SCIENCE

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Recent reports of the analysis of drugs of abuse in biological specimens are reviewed herein. Different perspectives from reviews so far published and the need for and the background of drug analysis in biological specimens, and difficulty of drug testing in biological specimens are introduced. Comprehensive biological specimens for the analysis of drugs of abuse in forensic science, including oral fluid (saliva), hair, umbilical cord, placenta, meconium, cadaver tissue (brain, adipose), sweat, breath, and nail clippings, in addition to the commonly used blood and urine specimens in clinical chemistry, are described along with their outlines, advantages/disadvantages, and actual examples. Today, liquid chromatography-tandem mass spectrometry (LC-MS/MS) is the method of choice for the analysis of drugs of abuse. A simultaneous screening method for multiple types of drugs has also become popular recently. However, because qualitative determination remains important in forensic science, gas chromatographymass spectrometry (GC-MS) is still in use even if it requires complicated specimen preparation and derivatization procedures. This is because GC-MS is reliable and has been employed ever since for the appraisal of trials.

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Application of discriminant analysis to differentiate between incorporation of cocaine and its congeners into hair and contamination

Cited by 57 publications

References 14 publications

Norcocaine and cocaethylene distribution patterns in hair samples from light, moderate, and heavy cocaine users

Norcocaine and cocaethylene distribution patterns in hair samples from light, moderate, and heavy cocaine users

Norcocaine in human hair as a biomarker of heavy cocaine use in a high risk population

Analysis of Drugs of Abuse in Biological Specimens

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