Time Optimization of Gas Chromatography-Mass Spectrometry Method for Controlled Substances Analysis

Abstract

An optimization of the gas chromatography- mass spectrometry (GC-MS) method was conducted by establishing a temperature ramp of 150°C, held by 3 min and raising at 12°C/min until reaching 300°C, which from 25.00 min was reduced to 15.50 min the analysis time and identified qualitatively the Caffeine, Cocaine, Delta 9 THC, Oxycodone and Heroin. A validation of the results was performed to determine the precision, instrument detection limit (IDL) and selectivity from six replicates analysis. For the controlled substances identification a 200 ppm QC-Standard Drug mix solution was prepared. A low variability was observed in the retention time of each compound. Instead, the peaks area demonstrates a high variability from the acceptance criteria of RSD, especially the Oxycodone affecting the IDL results. All the compounds showed a good resolution with acceptance criteria of R<2, except Oxycodone. Further measurements will be necessary to acquire more tight values to the acceptances criteria. Key Terms - Controlled substances, GC-MS, Temperature, Validation