Uncertainty of Postmortem Time Estimation Based on Potassium Ion Determination in Vitreous Humor Using Potentiometric Ion-Selective Electrode and Microwave-Induced Plasma with Optical Emission Spectrometry Methods

There is a need for reliable and independent evaluation confirmation of the postmortem interval (PMI) based on objective factors other than only changes or temperature measurements. Estimating PMI by examining concentration potassium ions in vitreous humor (VH) has tradition forensic toxicology dating back to mid-20th century. So far, methods determining presence have not been characterized terms measurement uncertainty types A B, which directly affect estimation time death uncertainty. The study evaluated determination ion concentrations using potentiometric ion-selective electrode (ISE) microwave-induced plasma with optical emission spectrometry (MIP-OES) methods. In addition, influence estimated results analysis VH was investigated. values expanded determined type experimental method indicate lower case MIP-OES ISE; that is, 2, 10, 25 mg/L ions, uncertainties were 1.2%, 2.2%, 2.5% ISE 12.2%, 6.1%, 3.1%, respectively. Similarly, estimating compared almost two times uncertainty; MIP-OES, it 2.53%, ISE, 4.75%. Both estimation, can be used interchangeably, as they provide comparable results.