Determination of Lidocaine in Postmortem Whole Blood Samples after Unsuccessful Cardiopulmonary Resuscitation

Forensic toxicologists often detect lidocaine in the biological fluids of the deceased, due to cardiopulmonary resuscitation (CPR) attempts prior to death. Here, we describe the development of a rapid, sensitive and robust method for the detection of lidocaine in postmortem whole blood using liquid-liquid extraction (LLE) followed by GC/MS analysis. The method showed a dynamic linear range of 100 to 6000 ng/mL with a linearity expressed by the regression coefficient (R-2) and a value of 0.9947. The quantitation limit (LOQ) was found to be 0.03 ng/mL and the detection limit (LOD) 0.01 ng/mL. Recovery accuracy and repeatability were satisfactory. Finally, the method was applied to 23 real whole blood samples from cases where CPR was attempted. Blood concentrations ranged from 0.21-0.96 mu g/mL.

Automated summary

The method developed for the detection of lidocaine in postmortem whole blood is rapid, sensitive, and robust, with a dynamic linear range from 100 to 6000 ng/mL and high accuracy. It was successfully applied to real blood samples from cases where CPR was attempted, showing blood concentrations ranging from 0.21-0.96 μg/mL.