Marta Sánchez

Applicability of an on-site test for its use in post-mortem blood

The number of deaths related to drugs of abuse makes necessary the use of an on-site test for those cases in which a rapid detection of the consumed drug is required. Cozart® DDS test provides a simple, fast and reliable tool for the qualitative on-site analysis in post-mortem blood. Owing that this test is prepared for oral fluid samples, a validation becomes essential in order to use it for a different matrix than the established one. According to that, results obtained by Cozart® DDS test used in post-mortem blood samples have been compared with a qualitative gas chromatography-mass spectrometry (GC/MS/MS). Positive results for cocaine family compounds (COC-F) were 43.75%, for opiates family compounds (OPI-F) 25.78%, and for cannabis family compounds (THC-F) 2.34%. Negative results were 28.13%. No amphetamines (AMP) or methamphetamines (MA) were found. Sensitivity and specificity was available for cocaine and opiates but not for cannabis because only five cases were detected. Sensitivity, specificity, predictive positive value and predictive negative value for cocaine were 98%, 91%, 88% and 99%, respectively. Sensivilty, specificity, predictive positive value (PPV) and predictive negative value (NPV) for opiates were 93%, 92%, 76% and 98%, respectively. Likelihood positive ratios for cocaine and opiates have been 10.92 and 11.69, respectively, while likelihood negative ratios have been 0.02 and 0.08, respectively. Results show the suitability of Cozart® DDS test for the qualitative detection of cocaine and opiates in post-mortem blood.

Drivers under the influence of drugs of abuse: Quantification of cocaine and impaired driving

In recent years, the interest in oral fluid as a biological matrix has significantly increased, particularly for detecting driving under the influence of drugs. In this study, the concentration of cocaine and its relationship with clinical symptoms in drivers suspected of driving under the influence of drugs was evaluated. A total of 154 samples of oral fluid, which tested positive for cocaine in previous immunoassay screening, Cozart Drug Detector System, were confirmed using gas chromatography/mass spectrometry method. In Catalonia, during 2007–2010, there were 1791 samples positive for cocaine among a total of 3468 samples taken from drivers who tested positive for any drug of abuse. The evaluation of clinical symptoms was through a questionnaire that was filled in by the police officers who collected the samples. The mean concentration of cocaine was 4.11 mg/l and median concentration was 0.38 mg/l (range 0.01–345.64 mg/l). Clinical impairment symptoms such as motor coordination, walking, speech, mood and state of pupils were not significant. The testing of oral fluids presents fewer ethical problems than blood or urine.

Comparison of the Cozart DDS 801 on-site drug test device and gas chromatography/mass spectrometry (GC/MS) confirmation results of cannabis and cocaine in oral fluid specimens

Driving under the influence of drugs (DUID) is a problem around the world. The objective of this study is to assess the reliability of the oral fluid screening device the Cozart DDS 801 by comparing the on-site results with confirmatory gas chromatography/mass spectrometry (GC/MS) oral fluid analysis. The study was carried out in Catalonia (Spain) with a sample of 2180 oral fluid specimens taken from subjects suspected of driving under the influence of drugs of abuse, and collected by police officers during 2009–2010. Statistical parameters of the tests were determined for cannabis and cocaine. The sensitivity, specificity, predictive positive value, predictive negative value, likelihood positive ratio and likelihood negative ratio for cocaine were 92%, 90%, 95%, 85%, 9.44, and 0.09 respectively. Sensitivity, specificity, predictive positive value, predictive negative value, likelihood positive ratio and likelihood negative ratio for cannabis were 87%, 86%, 94%, 73%, 6.15 and 0.6 respectively. Accuracy was 91% for cocaine and 86% for cannabis. The Cozart DDS 801 drug test system is a simple to use screening tool for cocaine and cannabis in oral fluid, at initial screening cut-off established by the manufacturer, confirmed with a GC/MS analysis. The system has demonstrated its acceptable performance.

Times of Detection of Drugs of Abuse in Saliva: Study of Arrested Population

Aim: Detection of drugs of abuse is interesting in legal procedures. The aims of the study were: 1: Evaluating the detection time of drugs of abuse in saliva in an arrested population, drugs consumers that are taken into judicial custody in a maximum time of 72 hours from their detention. 2- Verifying analytical results with self reported reference of the subjects. Participants: 50 oral fluid samples coming from arrested people that are taken into judicial custody in police officers courts of the city of Barcelona. The study was carried out in the Laboratory of the Institute of Legal Medicine of Catalonia. The design study was a cross sectional study. Drug tested were: cocaine, amphetamines and related compounds, cannabis and opiates. The time of previous consumption was of 1-3 days. Measurements: The oral fluid samples were analysed by gas- chromatography-mass spectrometry. Findings: Positive results were obtained in 40% of the samples. Cocaine was detected in the 73.9% of positive results to this drug. Cannabis was detected in the 28.5%, Opiates was detected in the 23, 1%. Amphetamines were not detected. Conclusions: It is important to stand out the high rate of cocaine positive results in relation with the time passed and abstinence consumption of 1-3 days. Oral fluid may be a good sample for cocaine detection in drug consumers.