Validated method for the simultaneous determination of Δ-THC and Δ-THC-COOH in oral fluid, urine and whole blood using solid-phase extraction and liquid chromatography–mass spectrometry with electrospray ionization

A fully validated, sensitive and specific method for the extraction and quantification of Δ⁹-tetrahydrocannabinol (THC) and 11-nor-9-carboxy-Δ⁹-THC (THC-COOH) and for the detection of 11-hydroxy-Δ⁹-THC (11-OH THC) in oral fluid, urine and whole blood is presented. Solid-phase extraction and liquid chromatography–mass spectrometry (LC–MS) technique were used, with electrospray ionization. Three ions were monitored for THC and THC-COOH and two for 11-OH THC. The compounds were quantified by selected ion recording of m/z 315.31, 329.18 and 343.16 for THC, 11-OH THC and THC-COOH, respectively, and m/z 318.27 and 346.26 for the deuterated internal standards, THC-d₃ and THC-COOH-d₃, respectively. The method proved to be precise for THC and THC-COOH both in terms of intra-day and inter-day analysis, with intra-day coefficients of variation (CV) less than 6.3, 6.6 and 6.5% for THC in saliva, urine and blood, respectively, and 6.8 and 7.7% for THC-COOH in urine and blood, respectively. Day-to-day CVs were less than 3.5, 4.9 and 11.3% for THC in saliva, urine and blood, respectively, and 6.2 and 6.4% for THC-COOH in urine and blood, respectively. Limits of detection (LOD) were 2 ng/mL for THC in oral fluid and 0.5 ng/mL for THC and THC-COOH and 20 ng/mL for 11-OH THC, in urine and blood. Calibration curves showed a linear relationship for THC and THC-COOH in all samples (r² > 0.999) within the range investigated.The procedure presented here has high specificity, selectivity and sensitivity. It can be regarded as an alternative method to GC–MS for the confirmation of positive immunoassay test results, and can be used as a suitable analytical tool for the quantification of THC and THC-COOH in oral fluid, urine and/or blood samples.     

Is the Walsh Contract Really Optimal?

The purpose of this paper is to show thatthe linear penalization to inflation foundin Walsh (1995) is not the government'soptimal choice when the fixed part of thetransfer scheme is any given constant and thepayment to the central bank represents acost for the government.     

抢抓机遇，实现中俄经贸科技合作新突破——赴俄罗斯考察中俄经贸科技合作情况的报告

20 0 1年 4月 ,黑龙江省赴俄经贸考察团分四个组对俄罗斯远东、西伯利亚地区以及莫斯科市进行了考察活动。考察人员一致认为 ,目前俄罗斯政治局面基本稳定 ,经济出现了恢复性增长 ,俄制定了一系列促进经济发展的新政策 ;黑龙江省与俄地方友好往来逐年增多 ,已奠定了良好的经贸科技合作基础 ,但合作层次低、规模小、领域窄的问题仍然存在 ;黑龙江省与俄开展经贸科技合作的潜力巨大 ,前景广阔。通过此次考察还总结了促进中俄经贸科技合作的六点有益的启示。考察活动成效很大 ,达到了预期的效果。     

Myths about workplace violence, harassment and bullying

The objective of this article is to examine myths about various forms of violence which occurs in the workplace. Harassment, bullying or hounding at work, is a problem which has increased in magnitude and needs to be addressed. We therefore analyse the nature, perception, accusations and prevention of such myths with the objective of clarifying the tangible and intangible effects on the health of the victim, and the results such harassment provokes on the organisation of the workplace.     

Introduction to the special issue on the importance of Simple Rules for a Complex World

European Journal of Law and Economics -     

Hot spots policing in a high-crime environment: an experimental evaluation in Medellín

Journal of Experimental Criminology - Test direct, spillover, and aggregate effects of hot spots policing on crime in a high-crime environment. We identified 967 hot spot street segments and...