The secret life of crime labs.

Houston TX experienced a widely known failure of its police forensic laboratory. This gave rise to the Houston Forensic Science Center (HFSC) as a separate entity to provide forensic services to the City of Houston. HFSC is a very large forensic laboratory and has made significant progress at remediating the past failures and improving public trust in forensic testing. HFSC has a large and robust blind testing program, which has provided many insights into the challenges forensic laboratories face. HFSC's journey from a notoriously failed lab to a model also gives perspective to the resource challenges faced by all labs in the country. Challenges for labs include the pervasive reality of poor-quality evidence. Also that forensic laboratories are necessarily part of a much wider system of interdependent functions in criminal justice making blind testing something in which all parts have a role. This interconnectedness also highlights the need for an array of oversight and regulatory frameworks to function properly. The major essential databases in forensics need to be a part of blind testing programs and work is needed to ensure that the results from these databases are indeed producing correct results and those results are being correctly used. Last, laboratory reports of "inconclusive" results are a significant challenge for laboratories and the system to better understand when these results are appropriate, necessary and most importantly correctly used by the rest of the system.

Interference of the novel designer benzodiazepine 4'-chloro deschloroalprazolam with alprazolam analysis in toxicology and seized drug DUID casework.

In recent years, the emergence of the novel designer benzodiazepine 4'-chloro deschloroalprazolam has presented a new challenge for forensic laboratories by interfering with the identification and quantitation of alprazolam. As an isomer of alprazolam, 4'-chloro deschloroalprazolam has similar physicochemical properties and can be misidentified in casework samples as alprazolam without a specific method to differentiate the two analytes. Starting in late 2021, the Houston Forensic Science Center (HFSC) received toxicological and seized drug evidence indicating the presence of 4'-chloro deschloroalprazolam. An interference study was performed to supplement the laboratory's validated benzodiazepines method for toxicological samples to differentiate alprazolam from 4'-chloro deschloroalprazolam. This study showed that while the isomers could not be chromatographically resolved using the current method, they could be differentiated based on their retention times relative to the internal standard, alprazolam-d5. Based on these findings, the HFSC toxicology laboratory reports test results as "unsuitable for analysis due to an interference" if a suspected alprazolam peak elutes before the alprazolam-d5 peak, even if all identification and quantification criteria (e.g., retention time) were acceptable. Additionally, the seized drug and toxicology laboratories re-evaluated previously analyzed alprazolam-positive casework to determine if suspected 4'-chloro deschloroalprazolam had been misidentified as alprazolam. This report presents three cases: one case with toxicological evidence indicating the presence of both 4'-chloro deschloroalprazolam and alprazolam, and two cases with both seized drug material and toxicology evidence indicating the presence of 4'chloro deschloroalprazolam with no detected alprazolam.

Evaluation of suspected drug-facilitated sexual assault cases in the city of Houston from 2014 to 2020.

Drug-facilitated sexual assault is a form of sexual violence against an individual incapacitated by alcohol and/or drugs consumed voluntarily or covertly administered. The purpose of this study was to evaluate toxicological results and the associated demographics of sexual assault-related cases submitted to Houston Forensic Science Center from 2014 to 2020. In total, 1240 samples (1230 cases) were tested during the six-year period that consisted of blood, urine, or both specimens. Blood was analyzed for ethanol by dual-column headspace gas chromatography with flame ionization detection. Drug screen analysis was performed preferably on urine specimens using enzyme-linked immunosorbent assay. Positive screening results were confirmed upon request only due to laboratory policy. A total of 22% (n = 176) of requested samples were confirmed positive. Ethanol was the most prevalent substance detected, present in 17% of the samples (n = 212), followed by 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (THC-COOH) (n = 118). The combination of ethanol and THC-COOH was the most frequent one found (n = 17) in cases positive for two or more drugs (n = 101). Demographic data showed the majority of DFSA victims were white (25%) females (72%) with an average age of 27 years old (n = 348). Almost 90% of cases where the presence of drugs was confirmed resulted in no charges being made, either due to lack of suspect information or unknown reasons by the laboratory.

A Comparison of High Drug Concentrations in Impaired Driving and Postmortem Casework in Harris County, TX.

Drug-impaired driving is a growing public safety issue. Addressing impairment due to drugs other than ethanol can be challenging for forensic toxicologists as many factors need to be considered including the type of drug(s), drug-drug interaction, the dose(s) and the individual's physiological condition and drug use history. Interpretation of blood drug test results is additionally difficult as drug concentrations in impaired driving cases may overlap levels typically viewed as toxic. This study compares blood concentrations of drugs in impaired driving cases to those in postmortem cases in Houston, TX, from 2014 to 2020. Blood drug concentrations from driving while intoxicated (DWI) or driving under the influence of drugs (DUID) cases submitted to Houston Forensic Science Center (HFSC) and Harris County Institute of Forensic Sciences (HCIFS) were compared to postmortem blood test results from HCIFS. Eight DWI/DUID cases had drugs that exceeded impaired driving concentrations reported in the literature. These drugs included fentanyl (220 ng/mL), oxycodone (680 ng/mL), hydrocodone (310 and 490 ng/mL), clonazepam (330 ng/mL), methamphetamine (3,500 and 7,100 ng/mL) and tetrahydrocannabinol (THC) (160 ng/mL). For oxycodone and hydrocodone, the presented DWI/DUID cases exceeded 91% and 96% of postmortem concentrations, respectively. The 7,100 ng/mL methamphetamine DWI/DUID result was greater than 98% of postmortem cases. The presented DWI/DUID concentrations were higher than all but one postmortem case for clonazepam and higher than all postmortem cases for THC. This study demonstrates that extremely high drug concentrations in DWI/DUID casework blur the line between therapeutic/recreational and toxic concentrations.

Blind testing in firearms: Preliminary results from a blind quality control program.

Open proficiency tests meet accreditation requirements and measure examiner competence but may not represent actual casework. In December 2015, the Houston Forensic Science Center began a blind quality control program in firearms examination. Mock cases are created to mimic routine casework so that examiners are unaware they are being tested. Once the blind case is assigned to an examiner, the evidence undergoes microscopic examination and comparison to determine whether the fired evidence submitted was fired in the same firearm. Fifty-one firearms blind cases resulting in 570 analysis and comparison determinations were reported between December 2015 and June 2021. No unsatisfactory results were obtained; however, 40.3% of comparisons in which the ground truth was either elimination or identification resulted in inconclusive conclusions. Due to the quality of some of the evidence submitted, inconclusive results were not unexpected. A ground truth of elimination and comparison result of inconclusive was observed at a rate of 74%, while a ground truth of identification and comparison result of inconclusive was observed at a rate of 31%. Bullets (61.8%) were the main contributors to inconclusive conclusions; variables such as the assigned examiners, training program, examiner experience, and the intended complexity of the case did not significantly contribute to the results. The program demonstrates that the quality management system and firearms section procedures can obtain accurate and reliable results and provides examiners added confidence in court. Additionally, the program can be tailored to target specific research questions and provide opportunities for collaboration with other laboratories and researchers.

Houston Cocktail: Driving under influence of hydrocodone, alprazolam, and carisoprodol.

Concurrent use of opioids, benzodiazepines, and skeletal muscle relaxants potentiates the drug effect and respiratory depression via interactions of µ-opioid and GABAA receptors. In the early 2000s when abuse of prescription drugs began to spike, a potent combination including hydrocodone, alprazolam, and carisoprodol, aka the "Houston Cocktail" or "Holy Trinity", emerged that may give users heroin-like euphoria. This research evaluated driving while intoxicated (DWI) cases that tested positive for hydrocodone, alprazolam, and carisoprodol, between 2015 and 2019. The blood samples were collected from drivers and submitted by the Houston Police Department (HPD). They were subsequently analyzed for alcohol and drugs by reference laboratories or Houston Forensic Science Center (HFSC). Toxicological findings, demographic information, and observed impairment were evaluated for the Houston Cocktail-positive DWI cases. A total of 80 DWI/DUID cases positive for hydrocodone, alprazolam, and carisoprodol in blood in which the traffic offense occurred between May 2015 and December 2019 were identified. Among these Houston Cocktail cases, the mean (median, range) concentrations were 75 (61, 6.9-322) ng/mL for hydrocodone, 58 (48, 5.8-180) ng/mL for alprazolam, and 3.9 (3.0, 0.3-14; n = 68) µg/mL for carisoprodol; 80 (100%) and 23 (29%) cases were also positive for meprobamate (mean 13; range 1.2-41 µg/mL) and hydromorphone (1.8; 1.0-3.3 ng/mL), respectively; carisoprodol and meprobamate in 12 of the cases were qualitatively detected. Forty six percent of those cases were females and 54% were males; 44% were Blacks, 46% were Whites, and 10% were other races as identified by the arresting officer. Mean (median) age of the drivers was 36 (34) years, ranged from 22 to 60 years. Twenty eight percent of the cases were positive for the Houston Cocktail only; 21% had one other drug/metabolite, 28% two, 14% three, and 10% had four or more additional drugs/metabolites. Of the 80 cases, cannabinoids were the most frequently detected analytes (35%), followed by codeine (11%). The drivers exhibited driving problems related to lane position, vigilance, judgment, speed, and/or braking. Many of the drivers (70-84%) had red/glassy eyes, slurred speed, poor balance, HGN and impaired divided attention. The present study showed that despite a traffic safety risk, drivers in Houston continue to use this dangerous drug combination. The risk is further exacerbated by the fact that the many drivers had yet other drugs in the system besides the three drugs.

Everything Is Bigger in Texas: Alcohol Impaired Driving in Houston (2014-2018).

Driving while intoxicated (DWI) or driving under the influence of drugs (DUID) poses a continued public safety risk in Texas, which has one of the highest alcohol impaired traffic fatality rates. This study aimed to identify alcohol and drug use trends seen in DWI/DUID cases in the city of Houston from 2014 to 2018 to better understand the populations at risk. Blood samples submitted to the Houston Forensic Science Center (HFSC) were evaluated for blood alcohol concentration (BAC), drug concentrations and demographics. During the 5-year period, 12,682 Houston driver blood samples had a mean (median) BAC of 0.151 g/dL (0.167 g/dL) and age of 36.3 (34) years. Fifty percent of samples were white males. Seventy-five percent of samples were individuals aged 21 to 44 years. Between 2014 and 2018, the number of cases submitted nearly doubled, from approximately 2,000 cases per year to over 3,700. In 2014, 23% of cases submitted required further analysis per HFSC testing policy (drug screen and confirmation for DWI/DUID cases when BAC < 0.100 g/dL), which rose to 27% by 2018. Of those, 36% were polydrug cases, requiring two or more confirmation tests. Cannabinoids was the most common drug class detected (34% of cases analyzed for drugs), followed by benzodiazepines (25%), phencyclidine (20%), cocaine/metabolites (15%) and opioids (12%). Phencyclidine rose from the fifth-most commonly detected drug in 2014 to the second-most drug in 2018. Only 3% of all cases (n = 408) were negative for both alcohol and drugs. Communication between law enforcement and laboratory management is recommended to address growing caseload more effectively. The study limitations (e.g., limited scope of analysis) suggest the present data underestimated the full extent of impaired driving in Houston, indicating even more urgent needs for increasing resources and efforts to reduce this serious threat to public safety.

Toxicological and Demographic Profiles of Phencyclidine-Impaired Driving Cases in Houston.

Phencyclidine (PCP) was first synthesized in 1926 and originally developed in 1950s as a general anesthetic agent. Abuse of PCP declined at the national level since its first illicit use in 1960s, but it continues in certain areas including Houston. This research evaluates PCP-positive cases of driving while intoxicated (DWI) in 2013-2018. The blood samples were collected from drivers, submitted by the Houston Police Department and analyzed for alcohol and drugs. Toxicological findings and demographic information were evaluated for the impaired driving cases tested positive for PCP in blood. Additionally, the Drug Recognition Expert (DRE) findings were examined for 12 cases in 2018. A total of 615 DWI cases positive for PCP in blood were identified in which the traffic offense occurred between August 2013 and December 2018. The mean (median, range) PCP concentration was 47 (43, 7-180) ng/mL. A total of 23% of those cases were females, and 77% were males; 85% were blacks, 10% were whites and 5% were other races/ethnicities as identified by the arresting officer. The mean age was 37 years. No significant differences in median and distribution of PCP concentrations (P's > 0.05) were observed across the offense years and among demographic cohorts. A total of 43% of the cases were positive for PCP only. Among the remaining 57%, cannabinoids are the most common concurrently detected analytes (35%), followed by cocaine/metabolite (14%) and ethanol (13%). The proportion of black male PCP-positive drivers decreased in younger age groups. Common indications observed by DRE officers included slurred speech, chemical breath odor, watery and/or bloodshot eyes, vertical/horizontal gaze nystagmus and impaired coordination/balance. This study provides valuable regional information to better understand the demographic patterns of PCP-impaired drivers in Houston, TX over 6 years. The findings may aid in designing and implementing regulations and prevention programs to reduce PCP-impaired driving.

Implementation of a Blind Quality Control Program in a Forensic Laboratory.

A blind quality control (QC) program was successfully developed and implemented in the Toxicology, Seized Drugs, Firearms, Latent Prints (Processing and Comparison), Forensic Biology, and Multimedia (Digital and Audio/Video) sections at the Houston Forensic Science Center (HFSC). The program was put into practice based on recommendations set forth in the 2009 National Academy of Sciences report and is conducted in addition to accreditation required annual proficiency tests. The blind QC program allows HFSC to test its entire quality management system and provides a real-time assessment of the laboratory's proficiency. To ensure the blind QC cases mimicked real casework, the workflow for each forensic discipline and their evidence submission processes were assessed prior to implementation. Samples are created and submitted by the HFSC Quality Division to whom the expected answer is known. Results from 2015 to 2018 show that of the 973 blind samples submitted, 901 were completed, and only 51 were discovered by analysts as being blind QC cases. Implementation data suggests that this type of program can be employed at other forensic laboratories.

Implementation of a Blind Quality Control Program in Blood Alcohol Analysis.

Declared proficiency tests are limited in their use for testing the performance of the entire system, because analysts are aware that they are being tested. A blind quality control (BQC) is intended to appear as a real case to the analyst to remove any intentional or subconscious bias. A BQC program allows a real-time assessment of the laboratory's policies and procedures and monitors reliability of casework. In September 2015, the Houston Forensic Science Center (HFSC) began a BQC program in blood alcohol analysis. Between September 2015 and July 2018, HFSC submitted 317 blind cases: 89 negative samples and 228 positive samples at five target concentrations (0.08, 0.15, 0.16, 0.20 and 0.25 g/100 mL; theoretical targets). These blood samples were analyzed by a headspace gas chromatograph interfaced with dual-flame ionization detectors (HS-GC-FID). All negative samples produced `no ethanol detected' results. The mean (range) of reported blood alcohol concentrations (BACs) for the aforementioned target concentrations was 0.075 (0.073-0.078), 0.144 (0.140-0.148), 0.157 (0.155-0.160), 0.195 (0.192-0.200) and 0.249 (0.242-0.258) g/100 mL, respectively. The average BAC percent differences from the target for the positive blind cases ranged from -0.4 to -6.3%, within our uncertainty of measurement (8.95-9.18%). The rate of alcohol evaporation/degradation was determined negligible. A multiple linear regression analysis was performed to compare the % difference in BAC among five target concentrations, eight analysts, three HS-GC-FID instruments and two pipettes. The variables other than target concentrations showed no significant difference (P > 0.2). While the 0.08 g/100 mL target showed a significantly larger % difference than higher target concentrations (0.15-0.25 g/100 mL), the % differences among the higher targets were not concentration-dependent. Despite difficulties like gaining buy-in from stakeholders and mimicking evidence samples, the implementation of a BQC program has improved processes, shown methods are reliable and added confidence to staff's testimony in court.

Use of SPME-HS-GC-MS for the analysis of herbal products containing synthetic cannabinoids.

The increasing prevalence and use of herbal mixtures containing synthetic cannabinoids presents a growing public health concern and legal challenge for society. In contrast to the plant-derived cannabinoids in medical marijuana and other cannabinoid-based therapeutics, the commonly encountered synthetic cannabinoids in these mendaciously labeled products constitute a structurally diverse set of compounds of relatively unknown pharmacology and toxicology. Indeed, the use of these substances has been associated with an alarming number of hospitalizations and emergency room visits. Moreover, there are already several hundred known cannabinoid agonist compounds that could potentially be used for illicit purposes, posing an additional challenge for public health professionals and law enforcement efforts, which often require the detection and identification of the active ingredients for effective treatment or prosecution. A solid-phase microextraction headspace gas chromatography-mass spectrometry method is shown here to allow for rapid and reliable detection and structural identification of many of the synthetic cannabinoid compounds that are currently or could potentially be used in herbal smoking mixtures. This approach provides accelerated analysis and results that distinguish between structural analogs within several classes of cannabinoid compounds, including positional isomers. The analytical results confirm the continued manufacture and distribution of herbal materials with synthetic cannabinoids and provide insight into the manipulation of these products to avoid legal constraints and prosecution.

Cocaine analytes in human hair: evaluation of concentration ratios in different cocaine sources, drug-user populations and surface-contaminated specimens.

Hair specimens were analyzed for cocaine (COC), benzoylecgonine (BE), cocaethylene (CE) and norcocaine (NCOC) by liquid chromatography-tandem mass spectrometry. Drug-free hair was contaminated in vitro with COC from different sources with varied COC analyte concentrations. Results were compared to COC analyte concentrations in drug users' hair following self-reported COC use (Street) and in hair from participants in controlled COC administration studies (Clinical) on a closed clinical research unit. Mean ± standard error analyte concentrations in Street drug users' hair were COC 27,889 ± 7,846 (n = 38); BE 8,132 ± 2,523 (n = 38); CE 901 ± 320 (n = 20); NCOC 345 ± 72 pg/mg (n = 32). Mean percentages to COC concentration were BE 29%, CE 3% and NCOC 1%. Concentrations in hair were lower for Clinical participants. COC contamination with higher CE, BE or NCOC content produced significantly higher concentrations (P = 0.0001) of all analytes. CE/COC and NCOC/COC ratios did not improve differentiation of COC use from COC contamination. COC concentrations in illicit and pharmaceutical COC affect concentrations in contaminated hair. Criteria for distinguishing COC use from contamination under realistic concentrations were not significantly improved by adding CE and NCOC criteria to COC cutoff concentration and BE/COC ratio criteria. Current criteria for COC hair testing in many forensic drug-testing laboratories may not effectively discriminate between COC use and environmental COC exposure.

A comparison of the validity of gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry analysis of urine samples II: amphetamine, methamphetamine, (±)-3,4-methylenedioxyamphetamine, (±)-3,4-methylenedioxymethamphetamine, (±)-3,4-methylenedioxyethylamphetamine, phencyclidine, and (±)-11-nor-9-carboxy-Δ9-tetrahydrocannabinol.

On November 25, 2008, the U.S. Department of Health and Human Services posted a final notice in the Federal Register authorizing the use of liquid chromatography-tandem mass spectrometry (LC-MS-MS) and other technologies in federally regulated workplace drug testing (WPDT) programs. To support this change, it is essential to explicitly demonstrate that LC-MS-MS, as a technology, can produce results at least as valid as gas chromatography (GC)-MS, the long-accepted standard in confirmatory analytical technologies for drugs of abuse. A series of manufactured control urine samples (n = 10 for each analyte) containing amphetamine, methamphetamine, (±)-3,4-methylenedioxyamphetamine, (±)-3,4-methylenedioxymethamphetamine, (±)-3,4-methylenedioxyethylamphetamine, phencyclidine, and (±)-11-nor-9-carboxy-Δ9-tetrahydrocannabinol at concentrations ranging from 10% to 2000% of federal cutoffs were analyzed with replication by five federally regulated laboratories using GC-MS and at RTI International using LC-MS-MS. Interference samples as described in the National Laboratory Certification Program 2009 Manual were analyzed by GC-MS and LC-MS-MS as well as previously confirmed urine specimens of WPDT origin. Matrix effects were assessed for LC-MS-MS. Results indicated that LC-MS-MS analysis produced results at least as precise, accurate, and specific as GC-MS for the analytes investigated in this study. Matrix effects, while evident, could be controlled by the use of matrix-matched controls and calibrators with deuterated internal standards.

A comparison of the validity of gas chromatography- mass spectrometry and liquid chromatography- tandem mass spectrometry analysis of urine samples for morphine, codeine, 6-acetylmorphine, and benzoylecgonine.

On November 25, 2008, the U.S. Department of Health and Human Services posted a final notice in the Federal Register authorizing the use of liquid chromatography-tandem mass spectrometry (LC-MS-MS) and other technologies in federally regulated workplace drug testing (WPDT) programs. These rules are expected to become effective in May 2010. To support this change, it is essential to explicitly demonstrate that LC-MS-MS as a technology can produce results at least as valid as gas chromatography-mass spectrometry (GC-MS), the long-accepted standard in confirmatory analytical technologies for drugs of abuse and currently the only confirmatory method allowed for use in support of federally regulated WPDT programs. A series of manufactured control urine samples (n = 10 for each analyte) containing benzoylecgonine, morphine, codeine, and 6-acetylmorphine at concentrations ranging from 10% to 2000% of federal cutoffs were analyzed with replication by five federally regulated laboratories using GC-MS (five replicate analyses per lab) and at RTI International using LC-MS-MS (10 replicate analyses). Interference samples as described in the National Laboratory Certification Program 2009 Manual were also analyzed by both GC-MS and LC-MS-MS. In addition, matrix effects were assessed for LC-MS-MS, and both analytical technologies were used to analyze previously confirmed urine specimens of WPDT origin. Results indicated that LC-MS-MS analysis produced results at least as precise, accurate, and specific as GC-MS for the analytes investigated in this study. Matrix effects, while evident, could be controlled by the use of matrix-matched controls and calibrators with deuterated internal standards. LC-MS-MS data parameters, such as retention time and product ion ratios, were highly reproducible.

External contamination of hair with cocaine: evaluation of external cocaine contamination and development of performance-testing materials.

The National Laboratory Certification Program undertook an evaluation of the dynamics of external contamination of hair with cocaine (COC) while developing performance testing materials for Federal Drug-Free Workplace Programs. This characterization was necessary to develop performance materials that could evaluate the efficacy of hair testing industry's decontamination procedures. Hair locks (blonde to dark brown/black) from five different individuals were contaminated with cocaine HCl. Hair locks were then treated with a synthetic sweat solution and hygienic treatments to model real-life conditions. Hair locks were shampooed daily (Monday through Friday) for 10 weeks, and samples of the hair locks were analyzed for COC, benzoylecgonine (BE), cocaethylene (CE), and norcocaine (NCOC). Three commercial analytical laboratories analyzed samples under three protocols: no decontamination procedure, individual laboratory decontamination, or decontamination by an extended buffer procedure at RTI International. Results indicated substantial and persistent association of all four compounds with all hair types. Hair that was not decontaminated had significantly greater quantities of COC and BE than did hair that was decontaminated. The only hair samples below detection limits for all four compounds were those decontaminated 1 h after contamination. Additionally, BE/COC ratios increased significantly over the 10-week study (regardless of decontamination treatment). From 21 days postcontamination until the end of the study, the mean BE/COC ratio for all hair types exceeded 0.05, the proposed Federal Mandatory Guidelines requirement. The largest variability in results was observed for samples decontaminated by participant laboratories. This suggests that current laboratory decontamination strategies will increase variability of performance testing sample results. None of the decontamination strategies used in the study were effective at removing all contamination, and some of the contaminated hair in this study would have been reported as positive for cocaine use based on the proposed Federal Mandatory Guidelines.

Urine benzodiazepine screening using Roche Online KIMS immunoassay with beta-glucuronidase hydrolysis and confirmation by gas chromatography- mass spectrometry.

Performance of the Roche Online KIMS (kinetic interaction of microparticles in solution) benzodiazepine (BZD) immunoassay (IA) with and without beta-glucuronidase treatment was evaluated on a Hitachi Modular automated IA analyzer calibrated using nordiazepam at 100 ng/mL. Reproducibility, linearity, accuracy, sensitivity, and interferences were evaluated. Precision of the assay (percent coefficient of variation (%CV)) with and without addition of the enzyme was less than 6% and 9%, respectively, with linearity (r(2) value of 0.9578 and 0.9746), respectively. Between-run precision of a 125 ng/mL nordiazepam control (n = 287) over 67 days, produced a %CV of 13.6% for the hydrolytic assay. Modification of the BZD assay to include automated hydrolysis of urinary BZD glucuronide conjugates was evaluated using three glucuronidated BZD standards prepared at concentrations ranging from 250 to 10,000 ng/mL. With hydrolysis, temazepam, oxazepam, and lorazepam glucuronides, produced cross-reactivities of 25%, 15%, and 20%, respectively. Without hydrolysis, the glucuronidated BZD standards produced less than 1% cross-reactivity in the assay. The ability of the assay to differentiate between positive and negative samples was evaluated by assaying 20 negative urine samples and serial dilutions of certified drug-free urine fortified with 28 different BZDs. All of the negative and positive urine samples produced the appropriate screening result. Cross-reactivities of 27 different BZDs, calculated as the normalized IA response divided by the BZD concentration that produced a response approximately equivalent to the response of a 100 ng/mL nordiazepam standard and multiplied by 100, ranged from 15% to 149%. Human urine samples (n = 28) that were previously found to contain BZDs by gas chromatography-mass spectrometry (GC-MS) also produced a positive BZD IA result. The IA was challenged with 78 potentially interfering compounds, and none produced a positive BZD response. As a part of the validation, a large number of human urine samples (29,500) were assayed using the modified Online BZD IA method to evaluate the performance of the method in production. Of the 29,500 samples tested, 80 produced a positive IA result. Analysis by GC-MS confirmed the presence of at least 1 BZD compound in 61 of the samples corresponding to a confirmation rate of 76%. The Online BZD IA modified by the automatic addition of beta-glucuronidase appears well adapted for the rapid detection of BZDs and their metabolites in human urine.

Analysis of nitrite in adulterated urine samples by capillary electrophoresis.

A simple method for analyzing nitrite in urine has been developed to confirm and quantify the amount of nitrite in potentially adulterated urine samples. The method involved separation of nitrite by capillary electrophoresis and direct UV detection at 214 nm. Separation was performed using a bare fused silica capillary and a 25 mM phosphate run buffer at a pH of 7.5. Sample preparation consisted of diluting the urine samples 1:20 with run buffer and internal standard, and centrifuging for 5 min at 2500 rpm. The sample was hydrodynamically injected, then separated using -25 kV with the column maintained at 35 degrees C. The method had upper and lower limits of linearity of 1500 and 80 microg/mL nitrite, respectively, and a limit of detection of 20 microg/mL. The method was evaluated using the National Committee for Clinical Laboratory Standards (NCCLS) protocol (Document EP10-A2), and validated using controls, standards, and authentic urine samples. Ten anions, ClO-, CrO4(-2), NO3-, HCO3-, I-, CH3COO-, F-, SO4-, S2O8(-2), and Cl-, were tested for potential interference with the assay. Interferences with quantitation were noted for only CrO4(-2) and S2O8(-2). High concentrations of Cl- interfered with the chromatography. The method had acceptable accuracy, precision, and specificity.

Urinary pharmacokinetics of 11-nor-9-carboxy-delta9-tetrahydrocannabinol after controlled oral delta9-tetrahydrocannabinol administration.

Understanding the pharmacokinetics of orally administered cannabinoids is vitally important for optimizing therapeutic usage and to determine the impact of positive tests on drug detection programs. In this study, gas chromatography-mass spectrometry (limit of quantitation = 2.5 ng/mL) was used to monitor the excretion of total 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THCCOOH) in 4381 urine voids collected from seven participants throughout a controlled clinical study of multiple oral doses of THC. The National Institute on Drug Abuse Institutional Review Board approved the study and each participant provided informed consent. Seven participants received 0, 0.39, 0.47, 7.5, and 14.8 mg THC/day for five days in this double blind, placebo-controlled, randomized protocol conducted on a closed research ward. No significant differences (P /= 15 ng/mL. An average of only 2.9 +/- 1.6%, 2.5 +/- 2.7%, 1.5 +/- 1.4%, and 0.6 +/- 0.5% of the THC in the 0.39, 0.47, 7.5, and 14.8 mg/day doses, respectively, was excreted as THCCOOH in the urine over each 14-day dosing session. This study demonstrated that the terminal urinary elimination t(1/2) of THCCOOH following oral administration was approximately two to three days for doses ranging from 0.39 to 14.8 mg/d. These data also demonstrate that the apparent urinary elimination t(1/2) of THCCOOH prior to reaching a 15 ng/mL concentration is significantly shorter than the terminal urinary elimination t(1/2). These controlled drug administration data should assist in the interpretation of urine cannabinoid results and provide clinicians with valuable information for future pharmacological studies.

Evaluation of ephedrine, pseudoephedrine and phenylpropanolamine concentrations in human urine samples and a comparison of the specificity of DRI amphetamines and Abuscreen online (KIMS) amphetamines screening immunoassays.

The purpose of this study was to evaluate the ability of two amphetamine class screening reagents to exclude ephedrine (EPH), pseudoephedrine (PSEPH), and phenylpropanolamine (PPA) from falsely producing positive immunoassay screening results. The study also sought to characterize the prevalence and concentration distributions of EPH, PSEPH, and PPA in samples that produced positive amphetamine screening results. Approximately 27,400 randomly collected human urine samples from Navy and Marine Corps members were simultaneously screened for amphetamines using the DRI and Abuscreen online immunoassays at a cutoff concentration of 500 ng/mL. All samples that screened positive were confirmed for amphetamine (AMP), methamphetamine (MTH), 3,4-Methylenedioxyamphetamine (MDA), 3,4-Methylenedioxymethamphetamine (MDMA), EPH, PSEPH, and PPA by gas chromatography/mass spectrometry (GC/MS). The DRI AMP immunoassay identified 1,104 presumptive amphetamine positive samples, of which only 1.99% confirmed positive for the presence of AMP, MTH, MDA, or MDMA. In contrast, the online AMP reagent identified 317 presumptive amphetamine positives with a confirmation rate for AMP, MTH, MDA, or MDMA of 7.94%. The presence of EPH, PSEPH, or PPA was confirmed in 833 of the 1,104 samples that failed to confirm positive for AMP, MTH, MDA, or MDMA; all of the 833 samples contained PSEPH. When compared to the entire screened sample set, PSEPH was present in approximately 3%, EPH in 0.9%, and PPA in 0.8% of the samples. The results indicate that cross reactivities for EPH, PSEPH, and PPA are greater than reported by the manufacturer of these reagents. The distribution of concentrations indicates that very large concentrations of EPH, PSEPH, and PPA are common.