Zeitschrift für forensische Forschung

Bland-Altman Statistical Analysis and Mean Concentration Ratio for the Determination of Amphetamine-type Stimulants-related Drugs in Dried Blood Stain (DBS) Versus Whole Blood Sample (WBS) by Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) Application to Forensic Toxicology Cases in Malaysia

Abstract

Fathiah A Zubaidi, Syaiful Izwan Ismail, Yeun-Mun Choo and Guan-Huat Tan

The performance of dried blood stain (DBS) versus whole blood sample (WBS) methods were evaluated using Bland-Altman analysis and mean concentration ratio for forensic toxicology cases in Malaysia. Common amphetamine-type stimulants related drugs of ephedrine, pseudoephedrine, amphetamine, methamphetamine, MDMA (3,4- Methylenedioxymethamphetamine), MDA (3,4-Methylenedioxyamphetamine), MDEA (3,4- Methylenedioxy-N-ethylamphetamine) and phentermine were investigated using DBS and WBS methods. The analysis was performed utilizing novel protocol consists of mass spectrometry detection technique based on a multiperiod and multi-experiment (MRM-EPI- MRM3) with library matching post liquid-liquid extraction of whole blood and corresponding DBS samples from spiked samples. The analysis was applied to 20 whole blood samples submitted for forensic and medico-legal analysis which were reported positive for the presence of the drugs. Results for both DBS and WBS were compared using Bland-Altman mean difference plots and mean concentration ratio for degree of agreement. The results showed good degree of agreements indicating no significant differences in results obtaining from DBS and WBS methods, allowing both methods to be used interchangeably. The study also demonstrated the advantage of the DBS method as an inexpensive alternative to WBS in the forensic toxicology field.