Development and validation of ELISA and GC-MS procedures for the quantification of dextromethorphan and its main metabolite dextrorphan in urine and oral fluid.

The development of a highly sensitive enzyme-linked immunosorbent assay and gas chromatography-mass spectrometry confirmation method for the detection of dextromethorphan and its major metabolite dextrorphan in urine and oral fluid is described. For the screening assay, the intraday precision was less than 8% for urine and less than 5% for oral fluid. The interday precision was less than 10% for both drugs in urine and oral fluid. For the confirmatory procedure, both inter- and intraday precision was less than 5% for both matrices. The detection limit for both methods was 1 ng/mL. The quantifying ions chosen from the full scan mass spectra were m/z 271 for dextromethorphan, m/z 329 for dextrorphan, and m/z 332 for tri-deuterated dextrorphan-d(3). A high recovery yield (> 93%) from the Quantisal oral fluid collection device was achieved, and the drugs were stable in the collection device for at least 10 days at room temperature. The extracted drugs from both matrices were stable for at least 48 h while kept at room temperature. Both screening and confirmatory procedures were applied to authentic urine and oral fluid specimens obtained from volunteers following therapeutic ingestion of dextromethorphan.

Training General Aviation Pilots for Convective Weather Situations.

BACKGROUND: Over the past 10-15 yr, considerable research has occurred for the development, testing, and fielding of real-time Datalink weather products for general aviation (GA) pilots to use before and during flight. As is the case with the implementation of most new technologies, work is needed to ensure that the users (in this case, the pilots) understand both the capabilities and limitations of the new technologies as well as how to use the new systems to improve their task performance. The purpose of this study was to replicate and extend a previous study on training pilots how and when to use these new weather technologies. METHOD: This field study used a quasi-experimental design (pre- vs. post-test with a control group). There were 91 GA pilots from the Midwest, Northeastern, and Southeastern United States who participated in a 2-h short course or a control activity. The lecture-based short course covered radar basics, Next Generation Weather Radar (NEXRAD), NEXRAD specifics/limitations, thunderstorm basics, radar products, and decision making. RESULTS: The pilots who participated in the course earned higher knowledge test scores, improved at applying the concepts in paper-based flight scenarios, had higher self-efficacy in post-training assessments as compared to pre-training assessments, and also performed better than did control subjects on post-test knowledge and skills assessments. DISCUSSION: GA pilots lack knowledge about real-time Datalink weather technology. This study indicates that a relatively short training program was effective for fostering Datalink weather-related knowledge and skills in GA pilots.

Identification and quantification of nicotine biomarkers in human oral fluid from individuals receiving low-dose transdermal nicotine: a preliminary study.

The objective of this preliminary study was to identify and quantify potential nicotine (NIC) biomarkers in post-exposure oral fluid samples collected from 10 NIC-abstinent human participants administered 7 mg transdermal NIC using liquid chromatography-tandem mass spectrometry (LC-MS-MS). Oral fluid samples were collected prior to NIC patch application and at 0.5 and 0.75 h after patch removal using the Quantisal() oral fluid collection device. The validated LC-MS-MS analyte panel included nicotine-Nbeta-D-glucuronide, cotinine-N-oxide, trans-3-hydroxycotinine, norcotinine, trans-nicotine-1'-N-oxide, cotinine (COT), nornicotine, NIC, anatabine, anabasine, and cotinine-N-beta-D-glucuronide. Analytes and corresponding deuterated internal standards were extracted by solid-phase extraction. NIC and COT concentrations were quantifiable in oral fluid samples collected from 6 of the 10 participants 0.5 h after patch removal and in oral fluid samples collected from 7 of the 10 participants 0.75 h after patch removal. Based on the mean NIC and COT concentrations in oral fluid and plasma for the participants with both quantifiable NIC and COT at the 0.5 and 0.75 h collection times, the oral fluid-plasma ratio was 6.4 for NIC and 3.3 for COT. An ELISA procedure was also validated and successfully applied as a screening tool for these oral fluid samples in conjunction with LC-MS-MS confirmation. An ELISA cut-off concentration of 5.0 ng/mL provided excellent sensitivity for discrimination of COT-positive post-exposure oral fluid samples collected after low-level transdermal NIC exposure and oral fluid samples collected prior to patch application.