Resumen de Analysis of a Suspected Drug Sample
Eric J. Schurter, Lois Anne Zook Gerdau, Paul S. Szalay
This general chemistry laboratory uses differences in solubility to separate a mixture of caffeine and aspirin while introducing the instrumental analysis methods of GCMS and FTIR. The drug mixture is separated by partitioning aspirin and caffeine between dichloromethane and aqueous base. TLC and reference standards are used to identify aspirin precipitated by acidifying the aqueous layer and the caffeine is recovered by evaporating the dichloromethane. FTIR analysis of the isolates is intended to provide an introduction to both the basic operation of a FTIR spectrometer and experience in matching library reference spectra to FTIR spectra of unknowns. GCMS analysis parallels the wet chemistry separation and FTIR identification of the components in the drug mixture. Used as a re-introduction to GCMS, emphasis is placed on how GCMS combines sample separation and component analysis into one operation. This laboratory is intended to be part of a suite of vertically integrated laboratory exercises linked by a forensic theme. Proceeding experiments in the suite are centered on the theory and application of TLC for forensic analysis. Subsequent experiments are focused on the use and interpretation of FTIR and GCMS for analysis.
