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.     

检测体液中氰含量的荧光光度法研究

本文报道了应用取代反应检测体液中氰含量的荧光光度法。探讨了检测的具体方法和有关条件对检测的影响。检测了正常人血、尿液和唾液中氰含量,并检测了小鼠氰化物染毒死亡后血中氰含量。研究表明,本法不但可检测体液中致死量的氰化物含量,亦可检测体液中正常氰含量。     

Roadside detection of impairment under the influence of ketamine--evaluation of ketamine impairment symptoms with reference to its concentration in oral fluid and urine

Although there are many roadside testing devices available for the screening of abused drugs, none of them can be used for the detection of ketamine, a popular abused drug in Hong Kong. In connection to local drug driving legislation, effective roadside detection of ketamine in suspected drug-impaired drivers has to be established. According to the drug evaluation and classification program (DEC), ketamine is classified in the phencyclidine (PCP) category. However, no study has been performed regarding the signs and symptoms exhibited by users under the influence of ketamine. In a study to develop a protocol for effective roadside detection of drug-impaired drivers, 62 volunteers exiting from discos were assessed using field impairment tests (FIT) that included measurements of three vital signs (i.e. body temperature, pulse rate and blood pressure), three eye examinations [pupil size, lack of convergence (LOC) and horizontal gaze nystagmus (HGN)] and four divided attention tests (Romberg, one-leg stand, finger-to-nose and walk-and-turn tests). Subsequent laboratory analysis of oral fluid and urine samples from the participants revealed the presence of common abused drugs in both the urine and oral fluid samples of 55 subjects. The remaining 7 subjects with no drug in their oral fluid samples were used as drug-free subjects. In addition, 10 volunteers from the laboratory who were regarded as drug-free subjects were also assessed using the same FIT. Among the 62 volunteers, 39 of them were detected with ketamine in their oral fluid. Of these ketamine users, 21 of them (54%) with only ketamine found in their oral fluid samples while the rest (18 subjects) of them had other drugs (i.e. MA, MDMA, benzodiazepines and/or THC) in addition to ketamine. Of the 21 ketamine-only users, 15 of them (71%) were successfully identified by FIT. It was found that when salivary ketamine concentrations were greater than 300 ng/mL, signs of impairment became evident, with over 90% detection rate using the FIT. By comparing the FIT observations on the 21 ketamine-only users with the drug-free subjects, the typical signs and symptoms observable for subjects under the influence of ketamine included LOC, HGN, elevated pulse rate and in general, failing the divided attention tests, especially the walk-and-turn and one-leg stand.     

A 1-year time course study of human RNA degradation in body fluids under dry and humid environmental conditions

Blood, saliva and semen are some of the forensically most relevant biological stains found at crime scenes. mRNA profiling is a reliable approach for the identification of the origin of an evidentiary trace. A stable set of markers and the knowledge about the effects of RNA degradation under different environmental conditions is necessary for the determination of an unknown biological stain. The aim of this work was to compare RNA degradation for human blood, semen and saliva at three different concentrations during a 1-year time period and exposed to dry and humid conditions. Also, this study addressed the question whether there are relevant differences in the efficiency of two RNA extraction methods.     

Analysis of Δ-tetrahydrocannabinol in oral fluid samples using solid-phase extraction and high-performance liquid chromatography–electrospray ionization mass spectrometry

An analytical method using solid-phase extraction (SPE) and high-performance liquid chromatography–mass spectrometry (LC–MS) has been developed and validated for the confirmation of Δ⁹-tetrahydrocannabinol (THC) in oral fluid samples. Oral fluid was extracted using Bond Elut LRC-Certify solid-phase extraction columns (10 cm³, 300 mg) and elution performed with n-hexane/ethyl acetate. Quantitation made use of the selected ion-recording mode (SIR) using the most abundant characteristic ion [THC + H⁺], m/z 315.31 and the fragment ion, m/z 193.13 for confirmation, and m/z 318.00 for the protonated internal standard, [d₃-THC + H⁺]. The method proved to be precise for THC, in terms of both intra-day and inter-day analyses, with coefficients of variation less than 10%, and the calculated extraction efficiencies for THC ranged from 76 to 83%. Calibration standards spiked with THC between 2 and 100 ng/mL showed a linear relationship (r² = 0.999). The method presented was applied to the oral fluid samples taken from the volunteers during the largest music event in Portugal, named Rock in Rio-Lisboa. Oral fluid was collected from 40 persons by expectoration and with Salivette^®. In 55% of the samples obtained by expectorating, THC was detected with concentration ranges from 1033 to 6552 ng/mL and in 45% of cases THC was detected at concentrations between 51 and 937 ng/mL. However, using Salivette^® collection, 26 of the 40 cases had an undetectable THC.     

Development and validation of the Cozart DDS oral fluid collection device

The testing of oral fluid for drugs of abuse has increased significantly over recent years and is now commonplace in drug rehabilitation clinics, the workplace, prisons and custody suites. The global problem of identifying drugged drivers has also led to an increase in oral fluid testing at the roadside. The main requirements for the implementation of roadside drug testing are a rapid sample collection time, collection of a known sample volume and recovery of drugs from the collection device. We report here the development of the Cozart^® DDS oral fluid collector, an oral fluid collector that combines rapid and adequate sample collection with satisfactory drug recovery. Oral fluid was collected from drug users (n = 134) and drug-free individuals (n = 137), using the Cozart^® DDS oral fluid collector. The mean time for the completion of collection (full coloration of the sample presence indicator) was 34 s for drug-free individuals and 44 s for drug users. The average volume collected was 0.34 mL (n = 271). No chemical stimulant (to induce salivation) was used to achieve the collection times observed in either the drug-free or the drug-taking sample populations. Drugs were extracted from the collector using the Cozart^® DDS buffer and drug recovery was determined by Cozart^® enzyme immunoassays. The recovery studies showed that for amphetamine, Δ⁹THC, cocaine, methadone, methamphetamine, morphine and temazepam over 90% of the drug in the sample was eluted from the collector. The Cozart^® DDS oral fluid collector provides a reliable mechanism for the collection of oral fluid at the roadside that achieves the rapid collection times required.     

乡土秩序的失落——对流动人口犯罪的社会学思考

流动人口犯罪的原因及其防治机制不能从流动人口群体以外的范围内去寻找 ,必须深入到生成流动人口的具体社会结构中去探寻。该社会结构主要有二方面要素 :城乡二元格局 ;户籍管理体制和现存的庞大剩余劳动力。流动人口犯罪的基础性原因是存在于流动人口群体中的乡土秩序在城市中的失落 ,以及由此而产生的流动人口生存与发展预期的落空。要解决这些问题 ,必须寻找一个重建秩序之路 ,也就是经过小城镇化而达到全面的城市化。其目标是消除两种秩序的差别和对立 ,直至建立最大限度遏制流动人口犯罪的新型秩序。     

用ELISA检测精液及精斑中精子抗原的研究

本实验应用单克隆抗人精子抗体和酶标记羊抗人精子抗体,采用ELISA方法确定精子抗原成份的存在。对10份新鲜精液,15份精斑进行了验测,其结果阳性率为100%。新鲜精液(精子数约10,000万个/ml)稀释100万倍,精斑浸出液稀释50万倍,均可出现阳性。对唾液斑、尿斑、乳汁斑、阴道斑、汗斑及输精管结扎的精液均为阴性。实验结果表明,本法检验精子抗原具有灵敏度高,特异性好的优点。