Simultaneous analyses of cocaine, cocaethylene, and their possible metabolic and pyrolytic products

A method was developed for simultaneously analyzing cocaine (COC), benzoylecgonine (BZE), norbenzoylecgonine (BNE), norcocaine (NCOC), ecgonine (ECG), ecgonine methyl ester (EME), m-hydroxybenzoylecgonine (HBZE), anhydroecgonine methyl ester (AEME), cocaethylene (CE), norcocaethylene (NCE), and ecgonine ethyl ester (EEE) in blood, urine, and muscle. Available deuterated analogs of these analytes were used as internal standards. Proteins from blood and muscle homogenate were precipitated with cold acetonitrile. After the removal of acetonitrile by evaporation, the supernatants and urine were subjected to solid-phase extraction. The eluted analytes were converted to their hydrochloride salts and derivatized with pentafluoropropionic anhydride and 2,2,3,3,3-pentafluoro-1-propanol. The derivatized products were analyzed by a gas chromatograph (GC)/mass spectrometer by selected ion monitoring. The limit of detection (LOD) for COC, BZE, NCOC, EME, CE, NCE, and EEE was 2ng/ml, while the LODs for BNE, ECG, HBZE, and AEME were 25, 640, 50, and 13 ng/ml, respectively. This method was successfully applied in analyzing 13 case samples from aviation accident pilot fatalities and motor vehicle operators. AEME concentrations found in the 13 samples were consistent with those produced solely by the GC inlet pyrolysis of COC controls in blood. Anhydroecgonine cannot be used as a marker for the abuse of COC by smoking because it is also pyrolytically produced from COC metabolites on the GC inlet. The developed method can be effectively adopted for analyzing COC and related compounds in urine, blood, and muscle by a single extraction with increased sensitivity through formation of hydrochloride salts and using a one-step derivatization.     

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

The requirement to differentiate between incorporation and external contamination of drugs into hair is undisputed, in particular when dealing with compounds which are administered by sniffing or inhalation (e.g. cocaine). With the aim of making this discrimination, hair samples from cocaine (COC) users (group IN) and seized cocaine samples (group OUT) were compared regarding the parameters benzoylecgonine (BZE), ecgonine methyl ester (EME), ecgonine (ECG), anhydroecgonine methyl ester (AEME), cocaethylene (CE) and norcocaine (NCOC). Since most of these compounds may be minor by-products of COC or be formed by biotransformation or chemical degradation, the stability of each substance was carefully examined. COC was found to be converted into significant amounts of BZE, EME and ECG even under mild extraction conditions, while traces of NCOC proved to be a ubiquitous by-product of COC. Cocaine positive hairs and seized cocaine samples (diluted to relevant concentrations) were equally preprocessed and analyzed by LC-MS-MS. Out of the metabolites listed above, NCOC, CE and AEME (each normalised to COC) were significantly increased in the incorporation group (i.e. hair samples from cocaine users). Based on this approach, a statistical discriminant analysis enabled us to make a prediction (and estimation of uncertainty) for each cocaine positive hair sample as to its likelihood of belonging to the group of cocaine users or of being contaminated.     

Levels of cocaine and its metabolites in washed hair of demonstrated cocaine users and workplace subjects

In a study of subjects in drug rehabilitation programs, cocaine and cocaine metabolite levels were determined in the hair of 75 subjects who had produced cocaine-positive urine results. The hair was analyzed after being washed with the 3.75 h wash procedure developed by this laboratory. In addition, results of testing 73 non-users are presented, as well as levels of cocaine, benzoylecgonine (BE), cocaethylene, and norcocaine from workplace population samples. The data support a recommendation of reporting as positive a sample with cocaine of 500 pg/mg hair and either a 5% ratio of benzoylecgonine (BE) to cocaine in samples, or the presence of cocaethylene at 50 pg/mg hair, or norcocaine at 50 pg/mg hair for samples < or =2000 pg cocaine/mg hair. For samples with cocaine present at >2000 pg/mg hair, the data indicate that a ratio of 5% BE may be an overly conservative approach. In appropriately washed hair samples, cocaine users can produce hair levels of <5% BE and thus a minimum BE cutoff in lieu of a ratio could be considered.     

LC-MS／MS测定尿液中可卡因及其代谢物苯甲酰爱康宁

目的建立尿液中可卡因(cocaine,COC)及其代谢物苯甲酰爱康宁(benzoylecgonine,BZE)的液相色谱-串联质谱分析方法。方法尿液经固相萃取后,用AllurePFP丙基柱分离,以V(甲醇):V(20mmol/L乙酸胺和0.1%甲酸的缓冲溶液)=80∶20为流动相,采用二级质谱多反应监测模式检测COC和BZE。按10mg/kg的剂量对豚鼠腹腔注射可卡因,给药后收集7d尿液。结果尿液中COC和BZE在2.0～100ng/mL质量浓度范围内线性关系良好(r=0.9995),最低检测限(LOD)为0.5ng/mL;回收率大于90%;日内和日间精密度均小于6%;豚鼠尿液中主要检测目标物是BZE,且BZE检测时限也较COC长。结论所建方法灵敏度高,选择性好,适用于尿液中可卡因和苯甲酰爱康宁的检测。     

Optimized conditions for simultaneous determination of opiates, cocaine and benzoylecgonine in hair samples by GC--MS

The present paper describes a qualitative and quantitative method for the simultaneous detection of opiates, cocaine and benzoylecgonine from human hair samples. Every step of the analytical procedure was studied to find the optimized conditions. Nine different incubation systems were examined. The influence of different pH values of samples on the isolation of analytes from the incubation media by Bond Elut cartridges and the stability of the compounds of interest in the different incubation media and conditions were investigated. The extracting power of different incubation media was studied as well. The phosphate buffer 0.1 N at pH 5 was chosen as the extraction medium in an optimized procedure for simultaneous determination of opiates, cocaine and benzoylecgonine in hair samples. The method developed was validated. Recoveries were 90% for morphine (M), 81% for 6-monoacetylmorphine (6-AM), 90% for codeine (CD), 86% for cocaine (C) and 90% for benzoylecgonine (BE). Relative standard deviation for inter-day precision was better than 12%. The limits of detection resulted as 0.05 ng/mg for M and C, as 0.08 for 6-AM and as 0.2 ng/mg for BE. Forty hair samples collected from drug abusers admitted to centers for detoxification treatment were analyzed obtaining 23 positive results for opiates and/or cocaine. Twelve hair specimens longer than 10 cm were analyzed following a sectional approach. In the six positive cases, it was interesting to find that the 6-AM/M ratio generally decreased for each sample from the proximal segment to the distal segments. Moreover, the 6-AM/M ratio was generally lower than 1 in the intermediate and distal segments.     

Screening for cocaine metabolite fails to detect an intoxication

Testing for the presence of cocaine (COC) is common in postmortem and clinical laboratories. COC use may be detected by screening urine specimens for COC metabolite. In the forensic arena, screening positive results are confirmed by a more specific and sensitive technique, such as gas chromatography-mass spectrometry. This article reports the case of an individual who died of COC intoxication but whose immunoassay screen (EMIT) for COC metabolite was negative. Gas chromatography-mass spectrometry analysis of the urine detected benzoylecgonine (BE) at a concentration of 75 ng/mL and COC at 55 ng/mL. These concentrations explain the negative screening result since the cutoff concentration of the assay was 300 ng/mL for BE. The reported cross reactivity with COC was 25,000 ng/mL. However, heart blood concentrations of COC and BE were 18,330 and 8640 ng/mL, respectively. The results from this case provide evidence that an EMIT test alone may fail to detect COC use. Individuals utilizing results of drug screening by immunoassay must be aware of the limitations of this testing methodology.     

Validation of an ion-trap gas chromatographic-mass spectrometric method for the determination of cocaine and metabolites and cocaethylene in post mortem whole blood

The coingestion of cocaine (COC) and ethanol is a very frequent occurrence and is known to increase the risk of morbidity and mortality. The formation occurs of a transesterification product, the cocaethylene (CE), which is even more toxic than cocaine. In order to study the role of ethanol as an agent of interaction in lethal cocaine intoxication, and to establish its influence in post mortem cocaine concentrations, an ion-trap gas chromatographic-mass spectrometric method (GC-MS) was validated to quantify simultaneously the agent and its biotransformation products, benzoylecgonine (BE), ecgoninemethylester (EME) and the 'biomarker' of the interaction, the CE present in whole blood. Deuterated internal standards were added to 2 ml of post mortem whole blood and extracted in Bond Elut Certify columns. The residues were evaporated and derivatized with N-methyl-N-t-butyldimethylsilyltrifluoroacetamide (MTBSTFA). Detection was performed by electron impact ionization. The monitored ions were m/z 82/85 for EME-tert-butyldimethylsilyl (TBDMS)/EME-d3-TBDMS; m/z 182/185 for COC/COC-d3; m/z 196/199 for CE/CE-d3 and m/z 282/285 for BE-TBDMS/BE-d3-TBDMS. The limits of detection and quantification were found to be 25 ng and 50 ng ml(-1), respectively, for COC and CE, and 50 and 100 ng ml(-1) for BE and EME. Accuracy was different for each of the compounds, varying from 65 to 98%. The dynamic range of the assay was 50-2000 ng ml(-1).     

Determination of opiates and cocaine in hair using automated enzyme immunoassay screening methodologies followed by gas chromatographic-mass spectrometric (GC-MS) confirmation

The objective of this study was to develop a two-step strategy for analysis of opiates and cocaine in hair samples involving an immunological screening procedure followed by confirmation of results using gas chromatography-mass spectrometry (GC-MS). A semi-quantitative automated competitive enzyme-linked immunosorbent assay (ELISA) methodology using Oral Fluid Micro-Plate Enzyme Immunoassays (Orasure Technologies, Inc.) was developed and validated. Applicability was proven by analysis of authentic head hair samples from drug users (n=103) and from opiate associated fatalities (n=21). The optimum cutoff values for the ELISA tests were 0.1 ng cocaine-equivalents/mg hair and 0.05 ng morphine-equivalents/mg hair using a 50 mg hair sample. Both ELISA tests had a sensitivity of 100%, the specificity was 66% for cocaine-equivalents and 42% for morphine-equivalents. The intraassay precision was 11% for the cocaine and 3% for the opiates ELISA, while interassay precision was 12% for the cocaine and 4% for the opiates ELISA test. The actual analyte concentrations in the hair samples were determined using GC-MS and were between 0.04 and 5.20 ng/mg for heroin (HER), between 0.04 and 30.01 ng/mg for 6-monoacetylmorphine (MAM), between 0.03 and 11.87 ng/mg for morphine (MOR), between 0.02 and 1.84 ng/mg for codeine (COD), between 0.02 and 2.48 ng/mg for acetylcodeine (AC), between 0.01 and 21.37 ng/mg for cocaine (COC), between 0.03 and 10.51 ng/mg for benzoylecgonine (BE) and between 0.05 and 1.26 ng/mg for cocaethylene (CE). The automated ELISA tests were proven to be valid screening procedures for the detection of cocaine and opiates in hair as confirmed by GC-MS. Screening methods provide rapid and inexpensive automated pre-test procedures to detect drugs in hair or other matrices. For forensic purposes screening therefore represents an ideal complement to routinely applied GC-MS procedures.     

Hair analysis for opiates,cocaine and metabolites. Evaluation of a method by interlaboratory comparison

The aim of this study was to evaluate the performance of a technique for the simultaneous testing of opiates, cocaine and metabolites in hair by interlaboratory comparison. Sixteen forensic and clinical laboratories with different degrees of experience in hair analysis participated voluntarily in the study (no selection criteria were applied). The suggested analytical procedure, the one routinely used in our laboratory, consisted of incubation in HCl 0.1N (45 degrees C, overnight), solid phase extraction (with Bond Elut Certify) cartridges), derivatisation (trimethylsilyl (TMS) derivatives) and GC-MS analysis. Three different mixtures of finely cut (1 mm or less) hair were prepared using drug-users' and drug-free hair: one 'negative' sample (<0.1 ng/mg for morphine, 6-acetylmorphine (6AM), cocaine and benzoylecgonine (BE)), one 'low concentration' sample (between 0.5 and 2 ng/mg) and one 'high concentration' sample (>3 ng/mg). Accuracy and precision (CV% lower than 5.1, 9.9, 5.2, 3.8, 7.3 and 8.3% for morphine, 6AM, codeine, cocaine, BE, and methylecgonine (ME), respectively; range 0.5-5 ng/mg) of the method and homogeneity of the mixtures were evaluated in our laboratory by intraday (CV% lower than 12% for all analytes) and interday analyses (CV% lower than 17% for all analytes except 6AM, 25%). Participants in the study were grouped into: (1) laboratories (n = 6) obtaining the best qualitative and quantitative values, corresponding to those with long experience in hair analysis; (2) laboratories (n = 5) with no reported false positive and/or false negatives; (3) laboratories (n = 5) with one or more reported false positives/false negatives. The results obtained by the labs of the first group were used as reference values. The scatter of data was similar to those obtained in other published studies.     

Simultaneous determination of opiates,cocaine and major metabolites of cocaine in human hair by gas chromotography/mass spectrometry (GC/MS)

A procedure is presented for the simultaneous identification and quantification of morphine (MOR), codeine (COD), ethylmorphine (EM), 6-monoacetylmorphine (6-MAM), cocaine (COC), benzoylecgonine (BZE), ecgonine methylester (EME) and cocaethylene (CE), contained in the hair of opiates and cocaine addicts. The method involves decontamination in dichloromethane, pulverization in a ball mill, heat-acid hydrolysis, addition of deuterated internal standards, liquid-liquid extraction and gas chromatography/mass spectrometry (GC/MS) after silylation. The limit of detection (LOD) was ~0.1–0.8 ng/mg for each drug, using a 30-mg hair sample. The method is reproductible, with a coefficient of variation (CV) of ~8–17%. Cocaine and 6-monoacetylmorphine were the major compounds detected in cases of cocaine (14 cases) and heroin (68 cases) intake. Concentrations were in the range 0.4–78.4 ng/mg (COC), 0.0–36.3 ng/mg (BZE), 0.0–1.6 ng/mg (EME), 0.0–2.1 ng/mg (CE), 0.0–84.3 ng/mg (6-MAM), 0.2–27.1 ng/mg (MOR) and 0.1–19.6 ng/mg (COD). An application in forensic sciences, involving multi-sectional analysis, is given.     

A Direct Aqueous Derivatization GSMS Method for Determining Benzoylecgonine Concentrations in Human Urine

A sensitive and reliable method for extraction and quantification of benzoylecgonine (BZE) and cocaine (COC) in urine is presented. Propyl‐chloroformate was used as derivatizing agent, and it was directly added to the urine sample: the propyl derivative and COC were then recovered by liquid–liquid extraction procedure. Gas chromatography–mass spectrometry was used to detect the analytes in selected ion monitoring mode. The method proved to be precise for BZE and COC both in term of intraday and interday analysis, with a coefficient of variation (CV) <6%. Limits of detection (LOD) were 2.7 ng/mL for BZE and 1.4 ng/mL for COC. The calibration curve showed a linear relationship for BZE and COC (r² >0.999 and >0.997, respectively) within the range investigated. The method, applied to thirty authentic samples, showed to be very simple, fast, and reliable, so it can be easily applied in routine analysis for the quantification of BZE and COC in urine samples.     

Comparison of daily urine,sweat, and skin swabs among cocaine users

This study (1) compares urine, skin swabs, and PharmChek sweat patches for monitoring drug use; (2) measures possible environmental contamination in recent cocaine (COC) users; and (3) evaluates various immunoassays (IA) for screening COC in diverse matrices. Unique aspects include daily urine monitoring of 10 participants for 4 weeks, multiple monitoring methods, analysis for all specimens by IA and gas chromatography (GC)/mass spectrometry (MS), and the potential for continued illicit drug use by participants. Urine served as the "gold standard" specimen for determining drug use. Only cocaine and related substances were detected.Trace amounts of drugs were found on the skin (<50 ng per swab) of urine-negative participants' hands or forehead. In contrast, larger quantities of COC were found on the skin of individuals with BE-positive urines or individuals living with drug users (up to 20 microg per swab). Patch COC amounts among the three regular users (250-9000, 0-240, 160-22,000 ng per patch) exceeded BE (50-950, none, 30-2200 ng per patch). Pre-swabs, valuable for interpreting the source or time frame of positive patch results, contained substantial COC (38-1160, 0-152, 34-762 ng per swab) prior to patch application; therefore, patch results may represent current use, prior use, contamination, or a combination. In three individuals with no indication of cocaine use, false positives (defined as sweat patch positive when urine specimens were <300ng BE/ml) occurred at a 7% rate. Proposed cut-off concentrations of 75 ng cocaine per patch and 300 ng BE/ml urine curtail the incidence of false positives in this limited population. Three immunoassays were compared to screen specimens for cocaine: a modified, manual Microgenics CEDIA; a Cozart ELISA; and an OraSure ELISA. CEDIA's limit of detection (LOD) was 81ng/ml, compared with LODs of 4 ng/ml for the Cozart ELISA and 1.5 ng/ml for the OraSure ELISA. Cozart correlated with OraSure results for COC concentrations <2000 ng per swab (n=117), r(2)=0.79.     

Detection and quantification of low levels of benzoylecgonine in equine urine

Cocaine (COC) is a highly addictive plant alkaloid expressing strong psychostimulatory effect. It has no medical use in equine veterinary practice. The contamination of the environment with cocaine such as its presence on the US paper currency has been reported few times. There are anecdotal reports of low benzoylecgonine (BE) concentrations (usually much less than 100 ng/mL) being found in urine of race horses. In order to protect horsemen against harsh penalties associated with the presence of trace amounts of BE in horse urine as a result of environmental contamination, in February 2005 the Illinois Racing Board issued new medication rules that established the threshold level of 150 ng/mL for BE in equine urine. The penalties associated with this rule provide for increasing fines ($250, $500, $1000) with successive positive reports against a trainer for levels of BE below 150 ng/mL. A total of 19,315 urine samples were collected over the 2-year period of time from winning horses (both harness and thoroughbred) at race tracks in Illinois for routine drug screening (ELISA). The presence of BE was confirmed by GC/MS in 28 urine samples (0.14%). The concentration range for BE in harness horses (21 detections) was < 5-91 ng/mL, and for thoroughbred (seven detections) was 7-52 ng/mL. To date, the laboratory has not reported concentrations of BE that exceed the established threshold concentration of 150 ng/mL.     

High-performance liquid chromatography with column switching for the determination of cocaine and benzoylecgonine concentrations in vitreous humor

A sample concentration technique was adapted for the determination of cocaine and benzoylecgonine (BE) concentrations in vitreous humor. Vitreous humor (0.5 mL) was diluted 1:1 with water and applied through a filter onto a 3-cm preconcentration column. Following a simple wash step, the analytes were flushed directly onto a reversed-phase analytical high-performance liquid chromatography (HPLC) system. Absolute recoveries were high (above 90%) and the chromatograms were free from interference. Analysis for the drug and its breakdown product was performed using ultraviolet (UV) visible photodiode array detection, which allowed confirmation of peak identity. Recognizable UV spectra could be measured with as little as 20 ng on column. Comparison of the drug levels in 27 blood and vitreous humor samples showed that, while there was only a low correlation between the blood and vitreous concentrations (R = 0.70), vitreous cocaine and BE determinations were good indicators of antemortem cocaine use. In almost all cases, the vitreous BE concentrations were higher than the cocaine concentrations. The technique was easy to perform and the vitreous samples were especially compatible with this low-labor analytical procedure.     

Simultaneous hair testing for opiates, cocaine, and metabolites by GC-MS: a survey of applicants for driving licenses with a history of drug use

A sensitive GC-MS method for the simultaneous determination of opiates, cocaine, and metabolites in hair at a cut-off level of 0.1 ng/mg was adopted to assess past exposure to these drugs in applicants for driving licenses with a history of drug use. The sampling protocol consisted of collection of one hair (sample A, 5-cm length) and one urine sample. When hair and urine (EMIT Syva, cut-off levels: 0.3 mg/l for opiates, 0.15 mg/l for cocaine, GC-MS confirmation of positives) were both positive or negative the protocol was concluded. In the other cases, the assessment of 'current exposure' to drugs was carried out, in order to avoid seriated random urinalysis, by collecting a second hair sample (sample B) 6 weeks later and analysing the proximal 1-cm segment. Out of the 214 'A' hair samples analyzed, 14 (6.5%) tested positive for morphine and/or 6-acetylmorphine (6AM), and 26 (12%) for cocaine and/or benzoylecgonine (BE), whereas none of the samples tested positive for both drugs. Levels between 0.1 and 1 ng/mg of the single analytes were found in eight out of the 14 morphine-6AM positives (57%) and in 18 out of the 26 cocaine-BE positives (69%). The time course of positive cases showed a progressive decrease of morphine-6AM positives and a corresponding increase of cocaine-BE positives within the study period September 1995-February 1999. No cases with positive urine and negative hair were observed. Among the 40 positive cases, seven (four and three for opiates and cocaine, respectively) were found to be 'currently exposed to drug', four by urinalysis (three and one) and three by analysis of the hair sample B (1 and 2).     

Markers of chronic alcohol use in hair: comparison of ethyl glucuronide and cocaethylene in cocaine users

Two direct ethanol metabolites, namely ethyl glucuronide (EtG) and cocaethylene (CE), in the hair of cocaine (COC) users were compared in this study. Hair samples (n=68) were submitted to the determination of EtG (by liquid chromatography-electrospray-tandem mass spectrometry) and of COC and metabolites, including CE (by gas chromatography-mass spectrometry). Quantitative and qualitative results were compared. No quantitative correlation was found between EtG and CE, as well as between EtG and the cocaethylene concentration divided by the concentration of COC and its metabolites (benzoylecgonine and ecgonine methylester, as COC equivalents). Nevertheless, many factors are supposed to affect the amount of the two substances incorporated in the hair matrix, such as the subject's habits in ethanol and COC use, genetic variability in the metabolism of both substances, and the different chemical and physical properties of EtG and CE. When establishing a cut-off of 4 pg/mg for EtG and of 200 pg/mg for CE, 47 samples tested positive for EtG and 41 samples tested positive for CE; 12 samples out of the 47 EtG-positives tested negative for CE (25%), whereas 6 samples out of the 41 CE-positives tested negative for EtG (15%). According to these data, EtG appears to be a more sensitive and specific marker of non-moderate alcohol users than CE.     

Detection of cocaine and its metabolites in breast milk

A method was developed for measuring cocaine and its metabolites, benzoylecgonine, ecgonine methyl ester, norcocaine, ecgonine ethyl ester, cocaethylene, and m-hydroxybenzoylecgonine, in breast milk by gas chromatography/mass spectrometry. Limits of detection for this method ranged from 2.5 to 10 ng/mL, and limits of quantitation ranged from 5 to 50 ng/mL. For each of the compounds measured by this method, linear response was demonstrated to 750 ng/mL. Breast milk was collected from 11 mothers who admitted to drug use during pregnancy and ten drug-free volunteers serving as control subjects. Cocaine was detected in six of the specimens obtained from drug-exposed subjects, and in none of the drug-free control subjects. In breast milk specimens where cocaine and one or more of its metabolites were detected, the concentration of parent compound was greater than any of the metabolites. The highest cocaine concentration found was over 12 microg/mL. Breast-fed infants of cocaine abusing mothers may be exposed to significant amounts of drug orally.     

Segmental analysis for cocaine and metabolites by HPLC in hair of suspected drug overdose cases

Hair samples of eight postmortem cases were analyzed in segments of 1 to 3 cm for cocaine, benzoylecgonine and cocaethylene. Samples were prepared for analysis by digestion in 0.1 M HCl and subsequent extraction with mixed-mode solid-phase extraction columns. Measurement was made by reversed-phase, narrow-bore HPLC and fluorescence detection using two laboratory-made internal standards. The concentrations were in the region of 0.29–316 ng/mg of hair for cocaine, 0.43–141 ng/mg of hair for benzoylecgonine and 0.93–1.83 ng/mg of hair for cocaethylene. All eight investigated cases had cocaine-positive segments. In six of the cases, all segments were positive, suggesting regular cocaine use and two showed in-between negative segments indicating an interruption or a change of the abuse intensity. The results showed a second, remarkable observation, i.e. enormous concentration differences (factor >150) for both cocaine and benzoylecgonine between the different subjects. Furthermore, interindividual cocaine/benzoylecgonine ratios ranged from 0.02 to 8.43. We believe these observations could in part be attributed to both some of the still existing limitations in the analytical approach(es), especially the mandatory hair washing steps, and in our still too limited knowledge of the hair incorporation processes. Nevertheless, in some cases, segmental analysis proved to be an important tool to distinguish, together with postmortem examination, deadly chronic abuse from single acute drug overdosage.     

Detection of cocaine and its polar transformation products and metabolites in human urine

This paper describes a method for the analysis of thermal degradation compounds generated from cocaine during the smoking process, together with chemical and enzymatic biotransformation products which, by virtue of their polarity, are not recovered by existing analytical procedures. The method employs cation exchange solid phase extraction coupled with gas chromatography/mass spectrometry. Compounds identified in urine from subjects of cocaine-related death included cocaine, benzoylecgonine, ecgonine methyl ester and ecgonine, which were measured quantitatively, and ecgonidine, ecgonidine methyl ester, ecgonine ethyl ester, ethyl benzoylecgonine, norcocaine, benzoylnorecgonine, cinnamoylcocaine, and cinnamoylecgonine. The concentrations of ecgonine (0–104 μg/ml) and ecgonine methyl ester (0–177 μg/ml) were substantial and averaged about one tenth the concentrations of benzoylecgonine (0–1074 μg/ml) and cocaine (0–1221 μg/ml). These and several of the other compounds identified will be valuable markers for cocaine use, in degraded samples and for indicating the route of administration.     

Hair analysis for cocaine: Factors in laboratory contamination studies and their relevance to proficiency sample preparation and hair testing practices

Hair samples were contaminated by rubbing with cocaine (COC) followed by sweat application, multiple shampoo treatments and storage. The samples were then washed with isopropanol for 15 min, followed by sequential aqueous washes totaling 3.5 h. The amount of drug in the last wash was used to calculate a wash criterion to determine whether samples were positive due to use or contamination. Analyses of cocaine and metabolites were done by LC/MS/MS. These procedures were applied to samples produced by a U.S. government-sponsored cooperative study, in which this laboratory participated, and to samples in a parallel in-house study. All contaminated samples in both studies were correctly identified as contaminated by cutoff, benzoylecgonine (BE) presence, BE ratio, and/or the wash criterion. A method for determining hair porosity was applied to samples in both studies, and porosity characteristics of hair are discussed as they relate to experimental and real-world contamination of hair, preparation of proficiency survey samples, and analysis of unknown hair samples.