Simultaneous determination of xylazine, free morphine, codeine, 6-acetylmorphine, cocaine and benzoylecgonine in postmortem blood by UPLC-MS-MS.

Xylazine, a veterinary sedative, has been found as an adulterant of heroin in street drugs in Puerto Rico. It was found in combination with free morphine and 6-acetylmorphine, codeine, cocaine and benzoylecgonine in postmortem cases at the Puerto Rico Institute of Forensic Sciences (PRIFS). Xylazine is not approved for human use because it has been proven harmful. Currently, three separate analyses are required to determine all the aforementioned drugs at the PRIFS's toxicology laboratory. To reduce analysis time consumption, sample volume, run time, sample preparation and cost, a high-throughput ultra-high-pressure liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous quantification of xylazine, free morphine, 6-acetylmorphine, codeine, cocaine and benzoylecgonine in 0.25 mL postmortem blood by protein precipitation, fulfilling confirmation criteria with three transitions for each compound with acceptable relative ion intensities. Linearity was established between 10-1,000 ng/mL. Total run time was 2.5 min. Limit of detection was 1 ng/mL for cocaine and xylazine, 2 ng/mL for 6-acetylmorphine and 10 ng/mL for free morphine, codeine and benzoylecgonine. The intra-day and inter-day precision and accuracy was less than 15.6%. Process efficiencies ranged from 35.9 to 123.4% and recoveries from 59.9 to 110.1%. The developed method was successfully applied to casework.

Motor vehicle accident fatalities trends, Puerto Rico 2000-2007.

Motor vehicle accident fatalities (MVAF) are an important cause of death that affects millions of people worldwide. Using the Puerto Rico Institute of Forensic Science database, this study accessed the mortality trends of MVAF in Puerto Rico from 2000 to 2007. Descriptive statistics, age-adjusted mortality rates, geographical analysis, and annual percentage change were calculated. An annual mean of 559 MVAF occurred during the study period. The overall MVAF mortality rate declined from 2000 to 2007 (16.6 and 12.4 per 100,000 population, respectively)-mortality rates annually decreased 3%. Most MVAF (80.2%) occurred in men, showing a risk four times higher than women (23.6 and 5.4 deaths per 100,000 populations, respectively). Drivers aged 20-24 years and pedestrians older than 75 years had the highest risk of death. This study emphasizes the need of public health efforts to focus on the prevention of MVAF in the most affected groups.