Determination of Specific Absorbance (A¦) for Six Psychoactive Drugs Encountered in Forensic Toxicology

Specific absorbance (A¦) is defined as the maximum absorbance of a 1% solution over a 1-cm path length measured via spectroscopy. Finding a reliable value for specific absorbance for a drug provides an important tool for the quantitative verification of concentration of analytical standards. Although many new drugs have emerged within the last ten years, many either do not have a reliable value for A¦, or a value simply has never been published. This work focused on determining the quantitative value of the specific absorbance of six psychoactive drugs using ultraviolet-visible spectroscopy, as well as comparing A¦ values of drugs purchased in 2017 to A¦ of their counterparts purchased in 2019. The drugs analyzed included Iloperidone, Risperidone, Aripiprazole, Vilazodone, Vortioxetine and Suvorexant.