Publications by authors named "I Alvarez-Freire"

Article Synopsis
  • A rapid and validated HPLC-PDA method was developed for extracting and quantifying zolpidem in plasma, ensuring high accuracy and recovery rates.
  • The method was successfully applied to ten real postmortem samples, revealing that most deaths involving zolpidem also included other substances like alcohol or drugs.
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Some South American countries have ancient traditions that may pose legal problems, such as the consumption of coca leaves, as this can provide positive results for cocaine use after the analysis of biological samples. For this reason, it is necessary to find specific markers that help differentiate legal from illegal consumption, such as tropacocaine, cinnamoylcocaine, and especially hygrine and cuscohygrine. In this work, two techniques for collecting biological samples are compared: the Quantisal Oral Fluid collection device and passive drooling.

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Hygrine and cuscohygrine, two coca leaf alkaloids, have been previously proposed as markers to differentiate legal and illegal cocaine consumption. This is a very common problem in some countries of South America, where the consumption of coca leaves has a long tradition. Analytical methods focusing on the assessment of coca leaf alkaloids, such as cuscohygrine, hygrine, tropacocaine and -cinnamoylcocaine, in oral fluid are virtually non-existent in forensic toxicology laboratories worldwide due to their lack of application.

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Research on the determination of drugs of abuse in hair has established that drugs can be detected in hair even long after cessation of use. The purpose of this study was to analyze hair samples from chronic opioid users who were beginning a controlled drug cessation program. The study population (n = 15) is involved in a drug rehabilitation program in Santiago de Compostela, Spain.

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