Rapid assay of cocaine, opiates and metabolites by gas chromatography-mass spectrometry

Drugs of abuse: management of intoxication and antidotes

Illicit drug intoxications are an increasing public health problem for which, in most cases, no antidotes are clinically available. The diagnosis and treatment of these intoxications requires a trained clinician with experience in recognizing the specific signs and symptoms of intoxications to individual drugs as well as polydrug intoxications, which are more the rule than the exception. To make the diagnosis, the clinical observation and a urine toxicology test are often enough. Evaluating the blood levels of drugs is frequently not practical because the tests can be expensive and results may be delayed and unavailable to guide the establishment of a treatment plan. Other laboratory tests may be useful depending on the drug or drugs ingested and the presence of other medical complications. The treatment should be provided in a quiet, safe and reassuring environment. Vital signs should be closely monitored. Changes in blood pressure, respiratory frequency and temperature should be promptly treated, particularly respiratory depression (in cases of opiate intoxication) or hyperthermia (in cases of cocaine or amphetamine intoxication). Intravenous fluids should be administered as soon as possible. Other psychiatric and medical complication should receive appropriate symptomatic treatment. Research on immunotherapies, including vaccines, monoclonal and catalytic antibodies, seems to be a promising approach that may yield specific antidotes for drugs of abuse, helping to ameliorate the morbidity and mortality associated with illicit drug intoxications.

Poppy seed foods and opiate drug testing--where are we today?

Seeds of the opium poppy plant are legally sold and widely consumed as food. Due to contamination during harvesting, the seeds can contain morphine and other opiate alkaloids. The objective of this study is to review the toxicology of poppy seed foods regarding influence on opiate drug tests. Computer-assisted literature review resulted in 95 identified references. Normal poppy seed consumption is generally regarded as safe. During food processing, the morphine content is considerably reduced (up to 90%). The possibility of false-positive opiate drug tests after poppy food ingestion exists. There are no unambiguous markers available to differentiate poppy food ingestion from heroin or pharmaceutical morphine use. This is also a problem in heroin-assisted maintenance programs. A basic requirement in such substitution programs is the patients' abstinence from any other drugs, including additional illicit heroin. Also a lack of forensic ingestion trials was detected that consider all factors influencing the morphine content in biologic matrices after consumption. Most studies did not control for the losses during food processing, so that the initial morphine dosage was overestimated. The large reduction of the morphine content during past years raises questions about the validity of the "poppy seed defence." However, a threshold of food use that would not lead to positive drug tests with certainty is currently unavailable. Research is needed to prove if the morphine contents in today's foods still pose the possibility of influencing drug tests. Future trials should consider processing-related morphine losses.

Rapid and sensitive determination of morphine in street opium samples by thermal desorption gas chromatography using a microfurnace pyrolyzer

Thermal desorption of the alkaloids in opium samples at 300 degrees C using a vertical microfurnace pyrolyzer was followed by their on-line gas chromatographic (GC) analysis on a large-bore glass capillary column. This method permitted rapid and sensitive determination of the content of the main alkaloid, morphine, in the small (ca. 100 microg) opium samples with a relative standard deviation within 4% for 5 runs. The observed morphine contents of about 12 to 15 w/w% in the given opium samples were in fairly good agreement with those estimated by a conventional GC-MS method.

Solid-phase microextraction in biomedical analysis

Chromatographic methods are preferred in the analysis of organic molecules with lower molecular mass (<500 g/mol) in body fluids, i.e., the assay of drugs, metabolites, endogenous substances and poisons as well as of environmental exposure by gas chromatography (GC) and liquid chromatography (LC), for example. Sample preparation in biomedical analysis is mainly performed by liquid-liquid extraction and solid-phase extraction. However, new methods are investigated with the aim to increase the sample throughput and to improve the quality of analytical methods. Solid-phase microextraction (SPME) was introduced about a decade ago and it was mainly applied to environmental and food analysis. All steps of sample preparation, i.e., extraction, concentration, derivatization and transfer to the chromatograph, are integrated in one step and in one device. This is accomplished by the intelligent combination of an immobilized extraction solvent (a polymer) with a special geometry (a fiber within a syringe). It was a challenge to test this novel principle in biomedical analysis. Thus, an introduction is provided to the theory of SPME in the present paper. A critical review of the first applications to biomedical analyses is presented in the main paragraph. The optimization of SPME as well as advantages and disadvantages are discussed. It is concluded that, because of some unique characteristics, SPME can be introduced with benefit into several areas of biomedical analysis. In particular, the application of headspace SPME-GC-MS in forensic toxicology and environmental medicine appears to be promising. However, it seems that SPME will not become a universal method. Thus, on-line SPE-LC coupling with column-switching technique may be a good alternative if an analytical problem cannot be sufficiently dealt with by SPME.

Liquid chromatography--tandem mass spectrometry analysis of cocaine and its metabolites from blood, amniotic fluid, placental and fetal tissues: study of the metabolism and distribution of cocaine in pregnant rats

The ability to simultaneously quantitate cocaine and its 12 metabolites from pregnant rat blood, amniotic fluid, placental and fetal tissue homogenates aids in elucidating the metabolism and distribution of cocaine. An efficient extraction method was developed to simultaneously recover these 13 components using underivatized silica solid-phase extraction (SPE) cartridges. The overall recoveries for cocaine and its metabolites were studied from pregnant rat blood (47-100%), amniotic fluid (61-100%), placental homogenate (31-83%), and fetal homogenate (39-87%). Extraction of the samples using silica is not classical SPE, but rather allows for the concentration of the sample into a small volume prior to injection and the removal of the proteins due to their strong interaction with the active silica surface. A positive ion mode electrospray ionization liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was used and validated to simultaneously quantitate cocaine and 12 metabolites from these four biological matrices. A gradient elution method with a Zorbax XDB C8 reversed-phase column was used to separate the components. Multiple reaction monitoring (MRM) of a product ion arising from the corresponding precursor ion was used in order to enhance the selectivity and sensitivity of the method. Low background noise was observed from the complex biological matrices due to efficient SPE and the selectivity of the MRM mode. Linear calibration curves were generated from 0.01 to 2.50 ppm. The method also showed high intra-day (n =3) and inter-day (n=9) precision (% RSD) and accuracy (% error) for all components. The limits of detection (LODs) for the method ranged from 0.15 to 10 ppb. The LODs of cocaine and its major metabolites were less than 1 ppb from all four biological matrices. This method was applied to the study of the metabolism and distribution of cocaine in pregnant rats following intravenous infusion to a steady state plasma drug concentration. The following results were observed in the pregnant rat study: (1) the observations correlated strongly with the previous literature data on cocaine metabolism and distribution, (2) cocaine and norcocaine accumulated in the placenta, (3) arylhydroxylation of cocaine was a major metabolic pathway, (4) para-arylhydroxylation of cocaine was favored over meta-arylhydroxylation in rats and (5) accumulation of cocaine and its major metabolites was observed in the amniotic fluid.

Simultaneous assay of morphine, morphine-3-glucuronide and morphine-6-glucuronide in human plasma using normal-phase liquid chromatography-tandem mass spectrometry with a silica column and an aqueous organic mobile phase

Morphine (MOR) is an opioid analgesic used for the treatment of moderate to severe pain. MOR is extensively metabolized to morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G). A rapid and sensitive method that was able to reliably detect at least 0.5 ng/ml of MOR and 1.0 ng/ml of M6G was required to define their pharmacokinetic profiles. An LC-MS-MS method was developed in our laboratory to quantify all three analytes with the required sensitivity and a rapid turnaround time. A solid-phase extraction (SPE) was used to isolate MOR, M3G, M6G, and their corresponding deuterated internal standards from heparinized plasma. The extract was injected on a LC tandem mass spectrometer with a turbo ion-spray interface. Baseline chromatographic separation among MOR, M3G, and M6G peaks was achieved on a silica column with an aqueous organic mobile phase consisting of formic acid, water, and acetonitrile. The total chromatographic run time was 3 min per injection, with retention times of 1.5, 1.9 and 2.4 min for MOR, M6G, and M3G, respectively. Chromatographic separation of M3G and M6G from MOR was paramount in establishing the LC-MS-MS method selectivity because of fragmentation of M3G and M6G to MOR at the LC-MS interface. The standard curve range in plasma was 0.5-50 ng/ml for MOR, 1.0-100 ng/ml for M6G, and 10-1000 ng/ml for M3G. The inter-day precision and accuracy of the quality control (QC) samples were <7% relative standard deviation (RSD) and <6% relative error (R.E.) for MOR, <9% RSD and <5% R.E. for M6G, and <3% RSD and <6% R.E. for M3G. Analyte stability during sample processing and storage were established. Method ruggedness was demonstrated by the reproducible performance from multiple analysts using several LC-MS-MS systems to analyze over one thousand samples from clinical trials.

Distinction among eight opiate drugs in urine by gas chromatography-mass spectrometry

Opiates are commonly abused substances, and forensic urine drug-testing for them requires gas chromatographic-mass spectrometric (GC-MS) confirmation. There are also medical reasons to test urine for opiates, and confirmation procedures other than GC-MS are often used for medical drug-testing. A thin-layer chromatographic (TLC) method distinguishes morphine, acetylmorphine, hydromorphone, oxymorphone, codeine, dihydrocodeine, hydrocodone, and oxycodone in clinical specimens. In certain clinical circumstances, GC-MS confirmation is requested for opiates identified by TLC, but, to our knowledge, no previous report examines all of the above opiates in a single GC-MS procedure. We find that they can be distinguished by GC-MS analyses of trimethylsilyl (TMS) ether derivatives, and identities of 6-keto opiates can be further confirmed by GC-MS analysis of methoxime (MO)-TMS derivatives. Inclusion of deuterium-labeled internal standards permits identification of the opiates in urine at concentrations below the TLC cutoff level of 600 ng/ml, and the GC-MS assay is linear over a concentration range that spans that level. This GC-MS procedure has proved useful as a third-stage identification step in a medical drug-testing sequence involving prior immunoassay and TLC.

Determination of drugs of abuse in blood

The detection and quantitation of drugs of abuse in blood is of growing interest in forensic and clinical toxicology. With the development of highly sensitive chromatographic methods, such as high-performance liquid chromatography (HPLC) with sensitive detectors and gas chromatography-mass spectrometry (GC-MS), more and more substances can be determined in blood. This review includes methods for the determination of the most commonly occurring illicit drugs and their metabolites, which are important for the assessment of drug abuse: Methamphetamine, amphetamine, 3,4-methylenedioxymethamphetamine (MDMA), N-ethyl-3,4-methylenedioxyamphetamine (MDEA), 3,4-methylenedioxy-amphetamine (MDA), cannabinoids (delta-9-tetrahydrocannabinol, 11-hydroxy-delta-9-tetrahydrocannabinol, 11-nor-9-carboxy-delta-9-tetrahydrocannabinol), cocaine, benzoylecgonine, ecgonine methyl ester, cocaethylene and the opiates (heroin, 6-monoacetylmorphine, morphine, codeine and dihydrocodeine). A number of drugs/drug metabolites that are structurally close to these substances are included in the tables. Basic information about the biosample assayed, work-up, GC column or LC column and mobile phase, detection mode, reference data and validation data of each procedure is summarized in the tables. Examples of typical applications are presented.

Evaluation of a fiber optic immunosensor for quantitating cocaine in coca leaf extracts

A fiber optic evanescent fluoroimmunosensor was used to rapidly detect and quantitate coca alkaloids as cocaine equivalents in leaf extracts of five Erythroxylum species. A monoclonal antibody (mAb) made against benzoylecgonine (BE), a major metabolite of cocaine, was immobilized covalently on quartz fibers and used as the biological sensing element in the portable fluorometer. Benzoylecgonine-fluorescein (BE-FL) was used as the optical signal generator when it bound to the fiber. If present, cocaine competed for the mAb and interfered with the binding of BE-FL, thereby reducing the fluorescence transmitted by the fiber. Calibration curves were prepared by measuring (over 30 s) the rates of fluorescence increase in the absence, or presence of cocaine. Ethanol or acid extracts of dry coca leaves were assayed by this fiber optic biosensor, gas chromatography and a fluorescent polarization immune assay. Biosensor values of cocaine content of leaves from five Erythroxylum species were not significantly different from gas chromatography values, but had higher variance. The biosensor assay was rapid and did not require cleanup of the crude leaf extracts. Cocaine in acid extracts was reduced significantly after 4 weeks at 23 degrees C and after 3 weeks at 37 degrees C. Fibers (mAb-coated), stored at 37 degrees C in phosphate-buffered solution (0.02% NaN3), gave stable responses for 14 days.

Applicability of various brands of mixed-phase extraction columns for opiate extraction from blood and serum

Four commercially available types of mixed-phase solid-phase extraction (SPE) columns (Bond Elut Certify, Isolute Confirm HCX, Chromabond Drug and Bakerbond Narc-2) were examined in order to compare the extraction efficiencies and chromatographic purity of extracts. The absolute recovery of morphine, 6-monoacetylmorphine and codeine was examined in blood and serum (ten samples each at two concentration levels), using SPE columns of the same batch. GC-MS (ion trap) and HPLC with amperometric detection were used for quantitation. A distinct variability in extraction recovery was observed among the same batches of all brands of SPE columns. All extracts were chromatographically pure and no interfering peaks were observed, neither in GC-MS nor in HPLC examinations, but in some extracts large peaks of plasticizers were identified. The measurements of flow velocities of the same samples of blood or serum through the SPE columns of the same batch showed very large variability of random character. The morphometric analysis of particles was performed for two batches of each sort of SPE columns by means of an image analysing system. Symmetrical distribution of particle size was observed only in Chromabond MN Drug packing, while in other cartridges large fractions of fine particles and nonhomogenous distribution were found. Only in one case the morphometric findings were pretty concordant with the data available from the manufacturer; in two cases, observed data varied considerably from that expected, and in one case no information was available at all. The study showed generally that there was room for improvement in the quality of mixed-phase SPE columns.

Quantitative determination of cocaine, cocaethylene (ethylcocaine), and metabolites in plasma and urine by high-performance liquid chromatography

A sensitive HPLC assay was developed to quantitate the relatively nonpolar compounds cocaine, cocaethylene (ethylcocaine), norcocaine, and norcocaethylene, as well as the relatively polar metabolites benzoylecgonine and benzoylnorecgonine, in rat plasma and urine. The assay in plasma employed two successive liquid-liquid extractions and separate injections onto two different columns (C8 and C18) to separate and quantitate the relatively polar and nonpolar compounds. In urine, the procedure employed a liquid-liquid extraction followed by solid-phase extraction (C18 light-load cartridges) and two separate injections as for plasma. The UV absorbance of the effluent was monitored at 235 nm. Linear standard curves were obtained over the concentration ranges of 25 to 1000 ng/mL and 5 to 250 ng/mL in plasma and urine, respectively. The inter- and intraday coefficients of variation for the assay of all compounds in plasma and urine were < 18% at low concentrations (12.5-100 ng/mL) and < 12% at high concentrations (125-250 ng/mL). There was no degradation of these compounds during the extraction procedure or during 2 months of storage at -20 degrees C. The quantitation limits for the assay of the relatively nonpolar and polar compounds in plasma were 25 (2.5 ng in 0.1 mL) and 50 ng/mL (5 ng in 0.1 mL), respectively. For the assay in urine, the quantitation limits were 5 (2.5 ng in 0.5 mL) and 12.5 ng/mL (6.25 ng in 0.5 mL) for the assay of the relatively nonpolar and polar compounds, respectively. The methods have been applied to quantitate those compounds in rat plasma.

Screening for drugs of abuse. I: Opiates, amphetamines and cocaine

(1) In order to provide an efficient and reliable service for drugs of abuse screening in urine, the laboratory should analyse 20-30 samples per week, and the staff should include a scientist with special expertise in the subject. (2) Turnaround times should be between 2-3 days of sample collection. To achieve this aim it may be necessary to make special arrangements for the delivery of samples to the laboratory. Results should preferably be transmitted by electronic mail or facsimile with the necessary precautions for security and confidentiality: hardcopy reports may also be required. (3) Good communications between the requesting clinician and the laboratory are essential. An advisory service should be provided by the laboratory and clinicians should be encouraged to discuss requests and results with laboratory staff. It is important that the laboratory inform doctors of the range of substances detected and the sensitivity and specificity of laboratory assays. (4) Assays should be performed according to the manufacturer's protocols, or by modified methods that have been rigorously validated. Quality control samples should be included in each analytical run and participation in an external quality assessment scheme, e.g. UKNEQAS, is essential to provide independent confirmation and confidence that results compare with those from other laboratories. Other requirements include adequate training and supervision of staff, and careful recording of samples and results. (5) Drugs to be tested will depend on the drug 'scene' in the area but should include those drugs regularly prescribed for maintenance therapy (e.g. methadone, dihydrocodeine, benzodiazepines), and drugs frequently misused (e.g. heroin, buprenorphine, amphetamines, cocaine). (6) Positive results obtained by preliminary screening methods e.g. EMIT, should be confirmed by another analytical technique, e.g. TLC, GC or GC-MS. If there are potentially serious or legal implications, and in employment and preemployment testing, confirmation of positive results is mandatory. In some cases, e.g. checking for methadone or benzodiazepine compliance, it may be considered unnecessary to confirm positive results although possible spiking of samples cannot be excluded without checking for the presence of metabolites by a chromatographic procedure.

Simultaneous assay of cocaine, heroin and metabolites in hair, plasma, saliva and urine by gas chromatography-mass spectrometry

As part of an ongoing research program on the development of drug detection methodology, we developed an assay for the simultaneous measurement of cocaine, heroin and metabolites in plasma, saliva, urine and hair by solid-phase extraction (SPE) and gas chromatography-mass spectrometry (GC-MS). The analytes that could be measured by this assay were the following: anhydroecgonine methyl ester; ecgonine methyl ester;. ecgonine ethyl ester; cocaine; cocaethylene; benzoylecgonine; cocaethylene; norcocaethylene; benzoylnorecgonine; codeine; morphine; norcodeine; 6-acetylmorphine; normorphine; and heroin. Liquid specimens were diluted, filtered and then extracted by SPE. Additional handling steps were necessary for the analysis of hair samples. An initial wash procedure was utilized to remove surface contaminants. Washed hair samples were extracted with methanol overnight at 40 degrees C. Both wash and extract fractions were collected, evaporated and purified by SPE. All extracts were evaporated, derivatized with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane (TMCS) and analyzed by GC-MS. The limit of detection (LOD) for cocaine, heroin and metabolites in biological specimens was approximately 1 ng/ml with the exception of norcodeine, normorphine and benzoylnorecgonine (LOD = 5 ng/ml). The LOD for cocaine, heroin and metabolites in hair was approximately 0.1 ng/mg of hair with the exception of norcodeine (LOD = 0.3 ng/mg) and normorphine and benzoylnorecgonine (LOD = 0.5 ng/mg). Coefficients of variation ranged from 3 to 26.5% in the hair assay. This assay has been successfully utilized in research on the disposition of cocaine, heroin and metabolites in hair, plasma, saliva and urine and in treatment studies.

Simultaneous detection of cocaine and heroin metabolites in urine by solid-phase extraction and gas chromatography-mass spectrometry

The present paper reports a method for the simultaneous extraction of cocaine, heroin and their metabolites from small amounts of urine (0.5 ml), using deuterated internal standards. Solid-phase extraction (SPE) on C18 columns followed by chromatographic separation coupled with mass spectrometry allowed the detection of all the substances after their derivatization. Mass spectrometry was performed in the electron-impact selected-ion monitoring (EI-SIM) mode. The limit of detection was found to be as low as 50 ng/ml for all the analytes; for reproducibility the C.V. was always better than 7%; the method was found to be linear with correlation coefficients between 0.989 and 1.00.

Reversed-phase high-performance liquid chromatographic determination of cocaine in plasma and human hair with direct fluorimetric detection

A simple, but sensitive and specific, high-performance liquid chromatographic assay for cocaine with direct fluorimetric detection, particularly intended for the routine analysis of hair and blood samples, is described. Benzoylecgonine, eluting before cocaine in a completely resolved peak, is also detectable. Detection is based on the weak native fluorescence of cocaine and benzoylecgonine, depending on the benzene ring present in both molecules. Hair samples (20-200 mg) were incubated overnight in 2 ml of 0.25 M HCl at 45 degrees C and extracted with a commercial liquid-liquid method; the dried residue reconstituted with 500 microliters of 0.05 M NaH2 PO4 (PH 5.2) was injected. Blood plasma samples (200 microliters) were mixed with 150 microliters of 0.1 M Na2 HPO4 (pH 8.9) and extracted with 5 ml of chloroform-2-propanol (9:1); the organic phase was evaporated and the residue dissolved and injected as above. Isocratic reversed-phase liquid chromatography was carried out on a column (150 x 4.6 mm I.D.) packed with spherical 5-microns poly(styrene-divinylbenzene) particles; the mobile phase was 0.1 M potassium phosphate (pH 3)-methanol-tetrahydrofuran (70:25:5). The excitation and emission wavelengths were set at 230 and 315 nm, respectively. Under the described conditions, cocaine eluted in a symmetrical peak with a capacity factor of about 5. The limit of detection was about 1 ng/ml (0.2 ng injected), with a signal-to-noise ratio of 3.(ABSTRACT TRUNCATED AT 250 WORDS)

Gas chromatographic-mass spectrometric determination of plasma and brain cocaine in mice

A gas chromatographic-mass spectrometric method is described for the determination of cocaine in mouse plasma microsamples and brain. Cocaine and [2H3]cocaine were extracted with pentane-isopropyl alcohol (97:3, v/v), chromatographed on a (5% phenyl) methylpolysiloxane capillary column, and detected by selected-ion monitoring of electron impact generated m/z 182 and 185 fragment ions. The small sample size (50 microliters), simplicity of workup, and high response linearity (mean r = 0.9993) distinguish the method. Cocaine was found in mouse brain at approximately 5 times greater concentration than in plasma after 20 or 40 mg/kg subcutaneous doses.