UC Davis

The Sacramento County District Attorney’s Laboratory of Forensic Services offers services in various scientific departments, such as toxicology, controlled substance (drug chemistry) analysis, firearms analysis, trace evidence, biology/DNA analysis, and more. The toxicology unit focuses on the analysis of biological samples, primarily blood and urine, for the presence of alcohol and drugs. For confirmation testing, the toxicology unit uses Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS) to analyze drugs in these samples. The toxicology unit has separate validated methods for analyzing different classes of drugs (depressants, stimulants, THC, opioids, etc.). These validated methods follow guidelines recommended by the American National Standards Institute/American Academy of Forensic Science Standards Board (ANSI/ASB) Standard 036: Standard Practices for Method Validation in Forensic Toxicology. The current method for quantitative analysis of opioids in blood samples (and qualitative for urine samples) was last validated by the Sacramento County Crime Lab in 2014. The opioids included within the scope of this method are morphine, hydromorphone, codeine, oxycodone, 6-monoacetylmorphine (6-MAM), hydrocodone, fentanyl, buprenorphine, and methadone. The goal of this project was to update and validate the method by adding five new target analytes and two deuterated analogs used as internal standards to the method: tramadol, o-desmethyltramadol, oxymorphone, norfentanyl, norbuprenorphine, tramadol-13C-D3, and oxymorphone-D3. Method parameters such as bias (accuracy), precision, linearity (calibration models), limit of detection (LOD), limit of quantification (LOQ), carryover, compound interference, matrix interference, ion suppression/enhancement, dilution integrity, extracted sample stability, and robustness/reproducibility (recommended by ANSI/ASB) were to be evaluated. Tramadol, o-desmethyltramadol, oxymorphone, norfentanyl, norbuprenorphine, tramadol-13C-D3, and oxymorphone-D3 were added to the original 2014 UPLC-MS/MS acquisition and processing methods for opioids. Test batches were run, and the quantifier/qualifier ion transitions, collision energies, and injection volumes were adjusted for certain analytes to improve the abundance levels of all twenty-five analytes. The next phase of the project is for other criminalists in the toxicology unit at the lab to extract and analyze test batches using the validated method and compare results. Once that is complete, the other validation parameters that can be checked are accuracy and precision, linearity, LOD and LOQ values, sample stability, and reproducibility.