A comparison between two different dried blood substrates in determination of psychoactive substances in postmortem samples

Abstract

Purpose Whatman™ 903 cards represent a valid type of support for collection, storage, and analysis of dried blood spots (DBS). Whatman™ FTA (Flinders Technology Associates) are a type of cards soaked in chemicals that cause denaturation of proteins, while preserving DNA and ensuring the safe handling of DBS; to date, these cards are still rarely employed in forensic toxicology. The aim of this study was to analyze several psychoactive substances on not-dried blood on the two different cards and to compare the qualitative and quantitative results. Methods Twenty cardiac postmortem blood samples were collected and deposed on Whatman™ 903 and Whatman™ FTA cards. Spots and not-dried blood were analyzed following our validated and previously published liquid chromatography–mass spectrometry methods. Results We were able to identify: eight drugs of abuse and their metabolites (15 cases), five benzodiazepines and their metabolites (3 cases), six antidepressants (6 cases) and two antipsychotics (3 cases). We observed a perfect qualitative correspondence and a general good quantitative correlation between data obtained from not-dried blood and the two different DBS cards, except for alprazolam, diazepam, desmethyldiazepam, fluoxetine and sertraline, that showed a lower concentration on FTA. Additional experiments suggest that the chemicals, adsorbed on FTA, are not the cause of the loss of signal observed for the substances previously mentioned and that methanol should be preferred as extraction solvent. Conclusions This study proved that FTA cards are a good and a hazard-free alternative sample storage method for analysis of several psychoactive substances in postmortem blood.

Analysis of Cannabinoids and Metabolites in Dried Urine Spots (DUS)

“…Recovery was evaluated at different sonication times (5,10,15,20,25 and 30 min). Fifteen minutes was considered as the best choice in terms of time saving and recovery.…”

“…Since the 1950’s, several methods have been developed and validated for dried blood spots [ 1 , 2 , 3 , 4 , 5 , 6 ]. Among DMS, dried urine spots (DUS) have successfully been used for several analytical purposes.…”

Emerging Microfluidic Devices for Sample Preparation of Undiluted Whole Blood to Enable the Detection of Biomarkers

“…Traditional methods of DNA extraction with phenol-chloroform, spin-columns, and magnetic beads can be time-consuming and expensive and need to be performed by trained personnel in a laboratory setting . Dried blood spot (DBS) samples, such as FTA Whatman and plasma separation cards, are newer low-cost alternatives where dried lysis and storage reagents on paper are activated upon sample spotting, thus eliminating the cell lysis step and simplifying sample preparation as well as improving sample storage and transportation for RLS. − The cards allow between 40 and 140 μL volume of blood per spot; however, previous reports have shown that volumes of 50–100 μL could lead to inaccurate detection of viral pathogens and so larger sample volumes might be required to ensure optimal performance. − Moreover, the uncontrolled flow of blood through the paper can cause the heterogeneous distribution of analytes within the sample spot, leading to variable results obtained from punching different areas of the DBS card. , The NA extraction protocol using these cards requires multiple washing steps to remove inhibitors prior to amplification. , A simpler method involves the addition of prelysed blood to a Whatman No. 1 filter paper disk, which, after a washing step, is added directly to the polymerase chain reaction (PCR) mix for amplification without removing the disk .…”

Dried Blood Spot in Toxicology: Current Knowledge

“…The vast majority of these drugs have a short half-life, but DBS has a stabilization effect on them so they can endure for a longer period [7]. It is also worth mentioning that a recent study by Moretti et al describes a successful analysis of a few psychoactive substances and their metabolites in postmortem blood [12]. However, research conducted by Patteet et al also confirmed that DBS is vital in therapeutic drug monitoring of antipsychotics, but it excluded olanzapine and N-desmethylolanzapine [13].…”