Evaluation of Sample Preparation Techniques for Matrix Effects and Absolute Recovery Using UPLC-MS/MS Using Opiates and Liver Tissue Specimens as the Model and Application to Post-Mortem Toxicology

As submitted by the applicant: Drug blood concentrations are commonly used in forensic science as a means in determining the cause and manner of death. Interpretation of blood drug concentration by themselves is often unreliable due to postmortem redistribution. Postmortem redistribution is the changes that occur
in drug concentrations after death due to redistribution of drugs into blood from solid organs such as the liver. The liver to peripheral blood ratio is a marker for postmortem redistribution. In the last decade, liquid chromatography tandem mass spectrometry (LC/MS−MS) has become a routinely used instrument in forensic laboratories. A weaknesses of LC/MS-MS is the possibility of a reduction (ion suppression) or an increase (ion enhancement) in the ionization of an analyte depending on the matrix of the sample analyzed. With the increase in LC/MS-MS use in forensic toxicology laboratories for analysis of drug in biological samples, a number simple rapid commercially available sample preparation techniques have become available. Limited published data for the matrix effect, absolute recovery and process efficiency of these techniques is available in liver. Due to their wide spread use and abuse, opiates have been chosen as a model for determining and evaluating matrix effect and absolute recovery in ten different sample preparation techniques. A previously optimized UPLC-MS/MS method for opiate will be used for the analysis. The UPLCMS/MS method for opiate analysis includes morphine, codeine, hydrocodone, hydromorphone, oxycodone, oxymorphone and 6-mono morphine and their isotopically labeled analogs which will be used as internal standards. This will impact forensic toxicology laboratories in that laboratories will become aware of potential advantages and disadvantages in eliminating/reducing matrix effects and absolute recovery of opiates analyzed in liver specimens using a variety of sample preparation techniques.

Note: This project contains a research and/or development component, as defined in applicable law.

ca/ncf