Performance of immunoassays in screening for opiates,cannabinoids and amphetamines in post-mortem blood

Several immunoassay methods for screening of abused drugs in whole blood were evaluated in post-mortem forensic toxicology. Blood samples known to be positive or negative for opiates, cannabinoids or amphetamines by gas chromatography-mass spectrometry (GC-MS) were analysed by EMIT II Plus and EMIT d.a.u., Syva RapidTest and Triage 8 after acetone precipitation. In these experiments, the EMIT immunoassay method was modified by using the Dade Behring VIVA analyser to detect substances more sensitively. Low concentrations of abused drugs were detected in blood samples. The sensitivities of the modified EMIT method for opiates, cannabinoids and amphetamines were 100, 86 and 98%, respectively, whereas the values were below 86% with the other methods. The specificities of all immunoassay methods for opiates and cannabinoids were 83% or above but 51-85% for amphetamines. Sample rejection occurred in a few cases with the EMIT amphetamine assays. The modified EMIT immunoassay system presented here seems to be useful for screening of drugs of abuse in post-mortem blood samples, especially when urine is not available.     

Roadside oral fluid testing: comparison of the results of drugwipe 5 and drugwipe benzodiazepines on-site tests with laboratory confirmation results of oral fluid and whole blood

Drugged drivers pose a serious threat to other people in traffic as well as to themselves. Reliable oral fluid screening devices for on-site screening of drugged drivers would be both a useful and convenient means for traffic control. In this study we evaluated the appropriateness of Drugwipe 5 and Drugwipe Benzodiazepines oral fluid on-site tests for roadside drug screening. Drivers suspected of driving under the influence of drugs were screened with the Drugwipe tests. Oral fluid and whole blood samples were collected from the drivers and tested for amphetamine-type stimulant drugs, cannabis, opiates, cocaine and benzodiazepines by immunological methods, GC and GC-MS. The performance evaluations of the tests were made by comparing the results of the Drugwipe tests with laboratory GC-MS confirmation results of oral fluid or whole blood. In addition to the performance evaluations of the Drugwipe tests based on laboratory results, a questionnaire on the practical aspects of the tests was written for the police officers who performed the tests. The aim of the questionnaire was to obtain user comments on the practicality of the tests as well as the advantages and weak points of the tests. The results of the performance evaluations were: for oral fluid (sensitivity; specificity; accuracy) amphetamines (95.5%; 92.9%; 95.3%), cannabis (52.2%; 91.2%; 85.1%), cocaine (50.0%; 99.3%; 98.6%), opiates (100%; 95.8%; 95.9%), benzodiazepines (74.4%; 84.2%; 79.2%) and for whole blood accordingly, amphetamines (97.7%; 86.7%; 95.9%), cannabis (68.3%; 87.9%; 84.9%), cocaine (50.0%; 98.5%; 97.7%), opiates (87.5%; 96.9%; 96.6%) and benzodiazepines (66.7%; 87.0%; 74.4%). Although the Drugwipe 5 successfully detected amphetamine-type stimulant drugs and the police officers were quite pleased with the current features of the Drugwipe tests, improvements must still be made regarding the detection of cannabis and benzodiazepines.     

Evaluation of two immunoassay procedures for drug testing in hair samples

A preliminary initial enzyme-linked immunosorbent assay (LUCIO-Direct ELISA kit) and a preliminary DRI enzyme immunoassay were evaluated for drug detection in head hair with respect to lowered cutoff values recommended in Germany for the control of abstinence in cases of re-granting of drivers' licences. Following drug classes were included: cannabinoids, opiates, cocaine like substances, amphetamine, methamphetamine (and methylenedioxyamphetamines), methadone, and benzodiazepines. 759 analyses were performed using LUCIO-Direct ELISA kits and 936 analyses using DRI enzyme immunoassay tests. Sample size for each drug group and immunoassay test reached from 74 to 178. The LUCIO-Direct ELISA kit revealed a sensitivity of 91% for amphetamine up to 98% for methadone (methamphetamine 92%, cocaine 94%, opiates 94%, benzodiazepines 96%) and values of specificity of 72% for methadone up to 89% for amphetamine and benzodiazepines. The test was not useful for a preliminary screening for tetrahydrocannabinol (sensitivity of 65%) in consideration of a suggested cutoff of 0.02 ng/mg. The DRI enzyme immunoassay test was only useful for morphine and cocaine testing at low recommended new cutoff values (0.1 ng/mg) revealing sensitivities of 94% and 99%, respectively.     

Prevalence of psychoactive substances in truck drivers in the Nord-Pas-de-Calais region (France)

A previous study conducted in 1995 showed that psychoactive drug use by workers was higher in safety/security workstations than in the rest of the labour force. In order to verify this finding, we conducted a new study in 2003-2004 in the Nord-Pas-de-Calais region, restricted to truck drivers. The aim of this study was to allow harmonizing the professional practice of the occupational physicians, proposing drug prevention and drug testing policies, validating the analytical methods and the guidelines in case of positive testing results. One thousand truck drivers were studied. Urines were tested for amphetamines, cannabinoids, cocaine, opiates, benzodiazepines, buprenorphine and methadone by immunoassay. Urine ethanol determinations were performed by an ADH method. Positive urines for drugs of abuse, methadone or buprenorphine were then tested by gas chromatography or liquid chromatography coupled to mass spectrometry. Out of the 1000 drivers, cannabinoids were detected in 85 cases, opiates in 41 cases, amphetamines in 3 cases and cocaine in only one case. Buprenorphine was detected in 18 cases, methadone in 5 cases and benzodiazepines in 4 cases. Urine ethanol was positive in 50 cases. We found only one case with 6-monoacetylmorphine. Other positive opiates were metabolites of antitussives. The relatively low number of benzodiazepine positive urines could be explained by the lack of sensitivity of the test we used. All these results confirm those of the previous study for cannabinoids and ethanol in safety/security workstations. Positive results for methadone and buprenorphine are eight times higher than in the general population. In conclusion, the authors think that it will be of a great interest to test urine of truck drivers for other classes of psychoactive drugs, using a liquid chromatography-mass spectrometry method.     

A 6-year experience with urine drug testing by family service agencies in Nova Scotia, Canada

The objective of this study is to describe a urine drug-testing program implemented for parents with a history of substance abuse by family service agencies in the province of Nova Scotia, Canada. Nurse collectors went to the parents' home to obtain urine specimens under direct observation and then delivered the specimens to the toxicology laboratory or arranged shipment by courier under chain of custody. Each urine specimen was screened for cannabinoids, cocaine metabolite, opiates, amphetamines and benzodiazepines, ethyl alcohol and creatinine. All positive screening tests were confirmed by another method such as gas chromatography-mass spectrometry (GC-MS). In 15,979 urine specimens collected from 1994 to 1999, the percent positive rate for one (or more) drugs/metabolites ranged from 45.6% (1994-1996) to 30.0% (1998, 1999). A total of 575 specimens (3.7%) were dilute (urine creatinine <25mg/dl). Positive rates in 15,404 non-dilute specimens from 1994 to 1999 were as follows: cannabinoids - 11.7%, benzodiazepines - 11.3%, cocaine metabolite - 3.7%, and ethyl alcohol - 2.6%. Most clients provided less than 20 urine specimens for testing but some individuals submitted urine specimens more than 100 times in a 12-15-month period. Urine drug screening in parents with a history of substance abuse provided an objective and reliable indication of recent drug use in this population.     

The use of oral fluid and sweat wipes for the detection of drugs of abuse in drivers

Blood, urine, oral fluid (by spitting or with a Salivette), and sweat samples (by wiping the forehead with a fleece moistened with isopropanol) were obtained from 180 drivers who failed the field sobriety tests at police roadblocks. With quantitative GC-MS, the positive predictive value of oral fluid was 98, 92, and 90% for amphetamines, cocaine, and cannabis respectively. The prevalence of opiate positives was low. The proposed SAMHSA cut-off values for oral fluid testing at the workplace, proved their usefulness in this study. The positive predictive value of sweat wipe analysis with GC-MS was over 90% for cocaine and amphetamines and 80% for cannabis. The accuracy of Drugwipe was assessed by comparing the electronic read-out values obtained on-site after wiping the tongue and the forehead, with the corresponding GC-MS results in plasma, oral fluid, and sweat. The accuracy was always less than 90% except for the amphetamine-group in sweat.     

The U.S. Mandatory Guidelines for Federal Workplace Drug Testing Programs: current status and future considerations

The U.S. Department of Health and Human Services (HHS) drug testing standards were published in 1988 and revised in 1994, 1998, and 2004. In 2004, significant revisions defining, standardizing, and requiring specimen validity testing on Federal employee donor urine specimens were included. In a separate notice, HHS proposed to establish scientific and technical guidelines for the Federal Workplace Drug Testing Program to: (1) permit laboratory testing of hair, oral fluid, and sweat patch specimens in addition to urine specimens for marijuana, cocaine, phencyclidine, opiates (with focus on heroin), and amphetamines [including methylenedioxymethamphetamine (MDMA), methylenedioxyethamphetamine (MDEA), methylenedioxyamphetamine (MDA)]; (2) permit use of on-site point of collection test (POCT) devices to test urine and oral fluid at collection sites; (3) permit use of instrumented initial test (screening only) facilities [IITF] to quickly identify negative specimens; and (4) add training requirement for collectors, on-site testers, and MROs. This proposal was published in the Federal Register on 13 April 2004, with a 90-day public comment period. The Substance Abuse and Mental Health Services Administration, HHS, reviewed those comments and is preparing the Final Notice that will define the requirements for such testing, including: specimen collection procedures, custody and control procedures that ensure donor specimen identity and integrity, testing facility, initial and confirmatory test cutoff concentrations, analytical testing methods, result review and reporting, evaluation of alternative medical explanations for presence of drug or metabolite in the donor's specimen, and laboratory certification issues. Voluntary pilot performance testing (PT) programs for each specimen type are on-going since April 2000 to determine how to prepare PT materials for specimens other than urine to evaluate laboratories' ability to routinely achieve accuracy and precision required. Certification programs will be developed using the current urine drug testing National Laboratory Certification Program model. The addition of accurate and reliable workplace drug testing using hair, oral fluid, and sweat patch specimens will complement urine drug testing, and aid in combating industries devoted to suborning drug testing through adulteration, substitution, and dilution. For example, hair testing may detect chronic drug use for up to 90 days and be useful in pre-employment situations; oral fluid testing may detect drug use in past hours and be useful in post-accident situations; sweat patch testing may be useful in follow-up drug testing and treatment programs; POCTs and IITFs may be most useful for quickly identifying specimens that are negative for drugs and indicate that the specimen is valid.     

Direct ELISA kits as a sensitive and selective screening method for abstinence control in urine

In 2009 cutoff values of assessment criteria to testify abstinence control in order to estimate driving ability were standardized in Germany. The cutoff values are lower than required in existing guidelines like SAMHSA and there is critical discussion about detection of low concentrations by using immunoassay, especially concerning amphetamines in urine (50 ng/ml). In this study Direct ELISA kits were tested for their applicability to identify the absence of amphetamines, cannabinoids, opiates, cocaine, methadone and benzodiazepines in urine. Results were confirmed by LC/MS or GC/MS analyses. Sensitivity, specificity, predictive values (positive as well as negative) and overall misclassification rates were evaluated by contingency tables and were compared to ROC-analyses. Sensitivity results as well as specificity results were satisfying showing sensitivity values higher than 96% for each analyte. The amphetamine test we used showed sensitivity and specificity of 100% and 88%, respectively, even if amphetamine tests usually react with high cross-reactivity. Our study results include high discrimination at required cutoff values between positives and negatives for each drug group and demonstrate that immunological tests complying with requirements of current decreased urine cutoff values for assessment of driving ability do exist.     

Comparison of the MTP immunoassay with EMIT in blood screening for drugs

We compared the MTP immunoassay with EMIT for the screening of drugs of abuse (opiates, cannabinoids, cocaine metabolites and amphetamines) in whole blood samples. These blood samples were obtained from the German police, when driving under the influence of drugs of abuse was suspected. For screening with the MTP immunoassay 25 microliters of serum or blood (without any pretreatment) was pipetted into the wells of the microtiter plates and the procedure was followed as described. Prior to screening with a Cobas Mira and EMIT reagents, the samples were treated with acetone to precipitate serum proteins. The cutoff for all drugs of abuse was set at 10 ng per ml of serum or blood. In most cases there was a good agreement between the negative and positive results of the two screening assays. The agreement between the two assays in the detection of opiates and cocaine was 91% and 93%, respectively, and for cannabinoids and amphetamines approximately 80%. The MTP immunoassay was more sensitive than EMIT for the detection of cannabinoids--but at the same time the MTP immunoassay was less specific. Both screening assays have a sensitivity of 100% for the detection of opiates and cocaine, but the specificity of the EMIT--also for opiates--was substantially lower. The MTP immunoassay has in respect to amphetamines a very high sensitivity, whereas the sensitivity of EMIT for amphetamines is inacceptable due to losses during sample preparation. The specificity of MTP immunoassay for amphetamines is not optimal, because a relatively large amount of samples tested false-positive for amphetamines at the cutoff of 10 ng/ml. In summary the MTP immunoassay, although not automated, performs well in comparison with EMIT, especially if the sample preparation for EMIT testing ist considered.     

Evaluation of the Cozart RapiScan drug test system for opiates and cocaine in oral fluid

The purpose of this study was to evaluate the efficiency of the Cozart RapiScan (CRS) drug test system for detecting opiates and cocaine in oral fluid. Oral fluid samples were collected using the Cozart RapiScan collection system from 358 donors who were receiving treatment for their addiction and were monitored for drug misuse. A further 103 oral fluid samples were collected from volunteer donors who were not drug users. The samples were analyzed in the laboratory using the two-panel Cozart RapiScan cartridge for opiates and cocaine and confirmed using gas chromatography-mass spectrometry (GC-MS). The samples were stored frozen at -20 degrees C until analysis by GC-MS. The overall accuracy of the CRS for both opiates and cocaine was 100%. Samples spiked at 50% above and below the cut-off consistently gave negative and positive results respectively. A total of 88 samples were positive for various opiates and 111 samples were positive for cocaine and/or its metabolites. The CRS for opiates and cocaine in oral fluid, using a cut-off of 30 ng/mL morphine or benzoylecgonine equivalents in neat oral fluid, had overall efficiencies of 98% and 99%, respectively, versus GC-MS. A series of potential adulterants of oral fluid were evaluated and shown not to alter the outcome of the test result.     

The determination of drugs of abuse in whole blood by means of FPIA and EMIT-dau immunoassays--a comparative study

Six groups of common drugs of abuse (cannabinoids, benzoylecgonine, opiates, barbiturates, benzodiazepines and amphetamines) were determined in whole blood after acetone precipitation, using enzyme multiplied immunoassay (EMIT dau) and fluorescence polarisation immunoassay (FPIA--Abbott TDx and ADx) methods. Both methods, designed primarily for urine, allowed the determination of all above mentioned class of drugs but amphetamine. Only 1 ml of a pre- or postmortem blood sample was needed. The sensitivity of cannabinoids determination was higher by FPIA. The FPIA method gave more precise results, particularly in the case of autopsy blood. The method was applied for drug screening in autopsy and police blood samples. The results (both positive and negative) were in agreement with those obtained with chromatographic methods.     

Proficiency testing (external quality assessment) of drug detection in oral fluid

Eighteen external quality assessment (proficiency testing) samples were prepared from client specimens collected with the Intercept oral fluid collection device and by spiking drug-free oral fluid. Samples were circulated in pairs at quarterly intervals to 13 UK and USA based laboratories for analysis by a panel of OraSure micro-plate Intercept enzyme immunoassay kits and hyphenated mass spectrophotometric techniques. During the survey, there was a single case of non-specificity in a false report for methadone. The major errors were of lack of sensitivity relative to the concentration thresholds specified for the immunoassays. The sensitivity for overall "present"/"not found" reports calculated as true positives/(true positives+false negatives) were for the amphetamine specific assay 50%, methyl-amphetamines 93%, barbiturates 64%, cannabinoids 73%, cocaine and metabolites 100%, benzodiazepines 69%, methadone 95%, opiates 79% (opiates excluding oxycodone 93%), phencyclidine 93% and human gamma-globulin 97%. A small number of the sensitivity errors were attributable to errors in chromatographic confirmation techniques.     

Driving under the influence of drugs -- evaluation of analytical data of drugs in oral fluid, serum and urine, and correlation with impairment symptoms

A study was performed to acquire urine, serum and oral fluid samples in cases of suspected driving under the influence of drugs of abuse. Oral fluid was collected using a novel sampling/testing device (Dr?ger DrugTest System). The aim of the study was to evaluate oral fluid and urine as a predictor of blood samples positive for drugs and impairment symptoms. Analysis for cannabinoids, amphetamine and its derivatives, opiates and cocaine was performed in urine using the Mahsan Kombi/DOA4-test, in serum using immunoassay and gas chromatography-mass spectrometry (GC-MS) confirmation and in oral fluid by GC-MS. Police and medical officer observations of impairment symptoms were rated and evaluated using a threshold value for the classification of driving inability. Accuracy in correlating drug detection in oral fluid and serum were >90% for all substances and also >90% in urine and serum except for THC (71.0%). Of the cases with oral fluid positive for any drug 97.1% of corresponding serum samples were also positive for at least one drug; of drug-positive urine samples this were only 82.4%. In 119 of 146 cases, impairment symptoms above threshold were observed (81.5%). Of the cases with drugs detected in serum, 19.1% appeared not impaired which were the same with drug-positive oral fluid while more persons with drug-positive urine samples appeared uninfluenced (32.7%). The data demonstrate that oral fluid is superior to urine in correlating with serum analytical data and impairment symptoms of drivers under the influence of drugs of abuse.     

Use of drugs of abuse in less than 30-year-old drivers killed in a road crash in France: a spectacular increase for cannabis, cocaine and amphetamines

A collaborative study was conducted in France in order to determine the prevalence of cannabinoids, opiates, cocaine metabolites and amphetamines in blood samples from drivers killed in road accidents in 2003 and 2004 and to compare these values with those of a previous study performed during the period 2000-2001 involving 900 drivers. Blood samples were provided from 2003 under 30-year-old drivers, killed in a traffic accident. Drugs of abuse were determined by gas chromatography-mass spectrometry using the same analytical procedures in all the 12 laboratories. The most frequently observed compounds were by far cannabinoids, that tested positive in 39.6% of the total number of samples. Delta9 tetrahydrocannabinol (THC), the most active of the principle constituents in marijuana (cannabis sativa), was detected in the blood of 28.9% drivers and was the single drug of abuse in 80.2% of the positive cases. It was associated with amphetamines in 7.4% and with opiates and cocaine in 1.9 and 4.8%, respectively. Amphetamines were present in 3.1% of the total number of samples, cocaine metabolites in 3.0% and opiates in 3.5%. When comparing these results with those of a previous study performed 3 years before, a significant increase is observed for THC (28.9% versus 16.9%), cocaine metabolites (3.0% versus 0.2%) and amphetamines (3.1% versus 1.4%). This study demonstrates the critical necessity of implementing in France as soon as possible systematical roadside testing for drugs of abuse.     

Evaluation of four oral fluid devices (DDS®, Drugtest 5000®, Drugwipe 5+® and RapidSTAT®) for on-site monitoring drugged driving in comparison with UHPLC-MS/MS analysis

New Italian legislation on driving under the influence of drugs considers oral fluid (OF) as a possible alternative drug testing matrix. On this basis, the present research was carried out to evaluate the applicability of four commercial on-site OF drug screening devices, namely DDS(?), Drugtest 5000(?), Drugwipe 5+(?) and RapidSTAT(?), in a real operative context. Preliminarily trained police officers tested randomly stopped drivers with two different kits side-by-side during roadside patrols. A central laboratory confirmed on-site kits' results by UHPLC-MS/MS analysis of the saliva specimen remaining after the screening analysis. 1025 drivers were submitted to the OF tests: 11.6% were positive for cocaine and metabolites, 11.1% for THC, 6% for amphetamines and amphetamine-type designer drugs and 2.3% for ketamine. The sensitivities of the kits were 81% (RapidSTAT(?)), 82% (DDS(?)), 90% (Drugwipe 5+(?)) and 97% (Drugtest 5000(?)) for cocaine and 38% (DDS(?)), 47% (Drugwipe 5+(?)), 72% (RapidSTAT(?)) and 92% (Drugtest 5000(?)) for THC. Drugtest 5000 was the only kit showing an acceptable sensitivity for on-site application. Only Drugtest 5000(?) and RapidSTAT(?) could be evaluated for amphetamines and methamphetamines: Drugtest 5000(?) showed a sensitivity of 100% in the case of amphetamines and 86% for methamphetamines, while RapidSTAT(?) 90% and 76% respectively. Nowadays, ketamine is not included in the target analytes of any on-site devices, but it was systematically included in the UHPLC-MS/MS confirmatory analysis. To ensure adequate reliability, MS confirmation of on-site OF screening tests is anyway always necessary, due to the presence of a significant number of false positive results even when using the commercial kit with the best performance.     

Detection of drugs of abuse in simultaneously collected oral fluid, urine and blood from Norwegian drug drivers

Blood and urine samples are collected when the Norwegian police apprehend a person suspected of driving under the influence of drugs other than alcohol. Impairment is judged from the findings in blood. In our routine samples, urine is analysed if morphine is detected in blood to differentiate between ingestion of heroin, morphine or codeine and also in cases where the amount of blood is too low to perform both screening and quantification analysis. In several cases, the collection of urine might be time consuming and challenging. The aim of this study was to investigate if drugs detected in blood were found in oral fluid and if interpretation of opiate findings in oral fluid is as conclusive as in urine. Blood, urine and oral fluid samples were collected from 100 drivers suspected of drugged driving. Oral fluid and blood were screened using LC-MS/MS methods and urine by immunological methods. Positive findings in blood and urine were confirmed with chromatographic methods. The analytical method for oral fluid included 25 of the most commonly abused drugs in Norway and some metabolites. The analysis showed a good correlation between the findings in urine and oral fluid for amphetamines, cocaine/benzoylecgonine, methadone, opiates, zopiclone and benzodiazepines including the 7-amino-benzodiazepines. Cocaine and the heroin marker 6-monoacetylmorphine (6-MAM) were more frequently detected in oral fluid than in urine. Drug concentrations above the cut-off values were found in both samples of oral fluid and urine in 15 of 22 cases positive for morphine, in 18 of 20 cases positive for codeine and in 19 of 26 cases positive for 6-MAM. The use of cannabis was confirmed by detecting THC in oral fluid and THC-COOH in urine. In 34 of 46 cases the use of cannabis was confirmed both in oral fluid and urine. The use of cannabis was confirmed by a positive finding in only urine in 11 cases and in only oral fluid in one case. All the drug groups detected in blood were also found in oral fluid. Since all relevant drugs detected in blood were possible to find in oral fluid and the interpretation of the opiate findings in oral fluid was more conclusive than in urine, oral fluid might replace urine in driving under the influence cases. The fast and easy sampling is time saving and less intrusive for the drivers.     

Results of hair analyses for drugs of abuse and comparison with self-reports and urine tests

Urine as well as head and pubic hair samples from drug abusers were analysed for opiates, cocaine and its metabolites, amphetamines, methadone and cannabinoids. Urine immunoassay results and the results of hair tests by means of gas chromatography-mass spectrometry were compared to the self-reported data of the patients in an interview protocol. With regard to the study group, opiate abuse was claimed from the majority in self-reports (89%), followed by cannabinoids (55%), cocaine (38%), and methadone (32%). Except for opiates the comparison between self-reported drug use and urinalysis at admission showed a low correlation. In contrast to urinalysis, hair tests revealed consumption in more cases. There was also a good agreement between self-reports of patients taking part in an official methadone maintenance program and urine test results concerning methadone. However, hair test results demonstrated that methadone abuse in general was under-reported by people who did not participate in a substitution program. Comparing self-reports and the results of hair analyses drug use was dramatically under-reported, especially cocaine. Cocaine hair tests appeared to be highly sensitive and specific in identifying past cocaine use even in settings of negative urine tests. In contrast to cocaine, hair lacks sensitivity as a detection agent for cannabinoids and a proof of cannabis use by means of hair analysis should include the sensitive detection of the metabolite THC carboxylic acid in the lower picogram range.     

Experience with urine drug testing by the Correctional Service of Canada

The Correctional Service of Canada implemented a urine drug-screening program over 10 years ago. The objective of this report is to describe the program and drug test results in this program for 1999. Offenders in Canadian federal correctional institutions and those living in the community on conditional release were subject to urine drug testing. Urine specimens were collected at correctional facilities and shipped by courier to MAXXAM Analytics Inc. laboratory. All urine specimens were analyzed for amphetamines, cannabinoids, cocaine metabolite (benzoylecgonine), opiates, phencyclidine, benzodiazepines, methyl phenidate, meperidine, pentazocine and fluoxetine by immunoassay screening (homogeneous EIA and ELISA assays) followed by GC-MS confirmation. Ethyl alcohol was analyzed when specifically requested. Alternative screening and confirmation methods with lower cut-off values were used, whenever urine specimens were dilute (creatinine <20mg/dl and specific gravity 相似文献   

New technology and new initiatives in U.S. workplace testing

A current perspective of workplace drug testing in the USA is presented covering three major issue areas: (1) epidemiology, (2) new technology and (3) initiatives to reach out and assist small business. First, national illegal drug-use self-reported survey data is compared with national laboratory drug testing results, illustrating a number of inconsistencies. During the 17-year period (1988-2004) the number of laboratory positive test results has decreased by 66% while during the same period self-reported drug-use has increased by 30%. The lack of concurrence between lab results and self-report surveys are examined in light of the typical panel of drugs being tested in U.S. laboratories, the increased specificity of immunoassay screening tests, and the critical issues of adulteration and substitution. Second, a brief review of the state-of-the-science in rapid point-of-collection (POCT) oral fluid drug-testing devices is presented along with some device evaluation findings. In general the window of drug detection in oral fluid is measured in hours. Most of the available oral fluid POCT devices can detect methamphetamine and amphetamines and opiates very well. The ability to detect cocaine appears to vary significantly across devices, while the ability to detect cannabis use is generally poor across all devices. Finally, efforts to reach out and assist small businesses in the development of workplace anti-drug programs are discussed in the context of increasing workplace programs in the European Union.     

Proficiency testing (external quality assessment) of drug detection in oral fluid

Eighteen external quality assessment (proficiency testing) samples were prepared from client specimens collected with the Intercept^® oral fluid collection device and by spiking drug-free oral fluid. Samples were circulated in pairs at quarterly intervals to 13 UK and USA based laboratories for analysis by a panel of OraSure micro-plate Intercept^® enzyme immunoassay kits and hyphenated mass spectrophotometric techniques. During the survey, there was a single case of non-specificity in a false report for methadone. The major errors were of lack of sensitivity relative to the concentration thresholds specified for the immunoassays. The sensitivity for overall ‘present’/‘not found’ reports calculated as true positives/(true positives + false negatives) were for the amfetamine specific assay 50%, methyl-amfetamines 93%, barbiturates 64%, cannabinoids 73%, cocaine and metabolites 100%, benzodiazepines 69%, methadone 95%, opiates 79% (opiates excluding oxycodone 93%), phencyclidine 93% and human gamma-globulin 97%. A small number of the sensitivity errors were attributable to errors in chromatographic confirmation techniques.