Validación del método de espectroscopia infrarroja para la determinación de cannabis sativa en muestras incautadas que ingresan al Laboratorio de Química Forense del Departamento de Criminalística de Chimborazo.

Abstract

The analytical method was validated in the determining of Cannabis sativa which entered to the Forensic Chemistry laboratory in the Chimborazo province from September 2014 to January 2015, using presumptive tests as colorimetric tests: Duquenois - Levine and Salt solid blue B testing positive for Cannabis sativa by changing color. Also it found the presence of trichomes after the microscopic observation. Confirmatory tests were also applied as chromatography in thin layer which revealed the presence of spots in cannabinoids areas. Furthermore Infrared Spectroscopy technique in order to make an assessment of the method by which some parameters set by the United Nations Office on Drugs and Crime were analyzed,, as the detection limit, obtaining 8.64mg / L of analyte concentration that can detect the equipment to the accuracy of the method under repeatability conditions, was obtained a relative standard deviation of 4.40% below the allowable limit of 5% . In the determination of specificity the spectra of the samples do not show interference with the characteristic peak of cannabinoids. The stability of the method was also evaluated; the samples subjected to different storage conditions do not stand with their own peak to cannabinoids. In conclusion it was found that the infrared equipment complies with the requirements for which it was designed, knowing that the performance parameters of the method provide a high degree of trust and confidence of results, ensuring expert reports of excellent quality as a support to provide justice. It is recommended to verify the data approach in the qualitative identification of delta-9-tetrahidrocarbocannabinol groups by Infrared Spectroscopy Fourier transform.