Analysis of Delta9-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 Delta(9)-tetrahydrocannabinol (THC) in oral fluid samples. Oral fluid was extracted using Bond Elut LRC-Certify solid-phase extraction columns (10 cm(3), 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, [d(3)-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 (r(2)=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.     

Allele frequencies and haplotypes of 8 Y-chromosomal STRs in the Santa Catarina population of southern Brazil

Allele frequencies and haplotypes of eight Y-chromosomal short tandem repeats (STRs), DYS19, DYS385, DYS389 I, DYS389 II, DYS390, DYS391, DYS392 and DYS393 were determined in a sample of 109 males from Santa Catarina. The origin of this southern Brazilian population is mainly from Portuguese people, namely from Azores archipelago.     

BRICS MEANS BUSINE

In Africa they say it is a positive sign if it rains at the start of an important event. That certainly seemed to hold true in South Africa’s premier eastern port city, where the Fifth BRICS Summit began with thunderous skies and unrelenting showers. As the flags of the five member     

El referéndum en latinoamérica: Un análisis desde el derecho comparado

This paper tells of the proliferation in recent decades, formulas referendums in Latin American constitutions. The comparative analysis of this mechanism to identify severalunique features in the treatment of this formula of direct democracy, which distinguish it from reflections from other disciplines. For now the simple regulation has meantaltering the form of state and government of various constitutional systems of our region.     

Just a Walk in the Park

One of the things that makes living in Beijing enjoyable is being able to walk through a public park on the way to work.The park in the northwestern part of the cityisasanctuaryforseniorcitizens,who pour down from the surrounding high-rise apartment blocks that characterize Beijing,to go through their time-honored morning rituals.At the park entrance are the"bird men."Most people who imagine life in China will no doubt have an image somewhere in their minds of elderly,vest-wearing men     

Cuba''s Revolutionary Foreign Policy Concept

At the invitation of Cui Liru, President of China Institutes of Contemporary International Relations (CICIR), Cuban Deputy Foreign Minister Marcos Rodriguez Costa paid a visit to CICIR on November 13, 2006. Following are the contents of his speech in CICIR.