Browsing by Author "Mader, Jade"

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Open Access
    Investigating the role of routine drug analyses in survivors of sexual offences admitted to the clinical forensic unit at Victoria Hospital
    (2024) Peters, Casey; Mader, Jade; Davies Bronwen
    Introduction: Toxicological analysis is an important component of drug-facilitated sexual assault (DFSA) investigations, as it allows for identification and interpretation of substances involved. Currently, forensic toxicological analyses are not routinely provided to DFSA survivors in South Africa. The aim of this study was to investigate the utilisation and applicability of a targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for common drugs of abuse in cases of suspected drug facilitated sexual offences. Methods: Blood and urine samples from 17 consenting adult survivors, who reported to the Clinical Forensic Unit at Victoria Hospital (August 2022 – December 2022) in Cape Town, South Africa, were analysed using a validated LC-MS/MS method targeting 31 common drugs of abuse. Samples were prepared for analysis using a Waters Ostro® pass-through plate extraction for blood and simple dilution extraction for urine. Case histories were obtained from participants by the attending medical practitioner using a standardised data collection sheet. Results: Majority of the participants reported to the clinic within 24 hours after the alleged offence (64.7%). Several participants reported consuming alcohol (64.7%), medicinal drugs (23.5%), or recreational drugs (35.3%) prior to, or at the time of the offence. A psychoactive drug was detected in 58.8% of cases. Methamphetamine (and its metabolite amphetamine) were the most frequently detected analytes (41.2% and 35.3% of cases, respectively). Conclusion: Accurate and reliable toxicological analysis is vital in processing DFSO cases. This study determined that the analytical method is useful in DFSO cases as over half of the participants tested positive for at least one drug, and most self-reported recreational drugs were included in the panel. Recommendations include expanding the panel to include additional pharmaceutical drugs and incorporating ethanol analysis into the routine workflow to provide comprehensive testing to survivors of DFSO and support the criminal justice system in South Africa.
  • Thumbnail Image
    Item
    Open Access
    Investigating the use of CO-oximetry for simultaneous measurement of carboxyhaemoglobin and methaemoglobin in post-mortem blood
    (2022) Muleya, Jane Mahlatse; Vuko, Loyiso; Mader, Jade; Davies, Bronwen
    Carbon monoxide (CO) is a gas that exerts its toxicity on humans, when inhaled, by bonding with haemoglobin (Hb) to produce carboxyhaemoglobin (COHb). This results in tissue hypoxia which can be fatal at high blood saturation levels. Carboxyhaemoglobin may be measured using a Radiometer ABL825 FLEX analyser, a spectrophotometric instrument that applies a technique called CO-oximetry to measure Hb derivatives such as COHb and methaemoglobin (MetHb). The latter is an oxidised form of Hb that can cause or contribute to mortality at high concentrations. Methaemoglobin is notorious for its instability in vitro. This study, therefore, sought to determine handling conditions best suited for the stability of MetHb in post-mortem blood such that the ABL825 FLEX analyser may be used for the simultaneous measurement of COHb and MetHb. To this end, blood samples collected from 15 cases of potential CO poisoning at Salt River Mortuary were aliquoted into red (no additive)-, green (containing lithium heparin)-, and purple (containing ethylenediaminetetraacetic acid)-top tubes. The samples were stored at 4°C or –80°C and retrieved from storage on days 0, 1, 4, 7, 14, and 30, for analysis. While COHb remained stable in all storage conditions over a 30-day period, this was not true for MetHb. When samples were stored at 4°C, a rapid increase followed by a gradual decline was observed for MetHb in all the tube types investigated. The MetHb content was at its lowest after two weeks of storage, which was consistent with COHb levels at the same time period and temperature. At –80°C, continuous increase of MetHb was observed, with the samples stored in green-top tubes showing the least amount of overall change from the reference (day zero) values. The study provided useful data regarding the stability of MetHb under the considered storage conditions, the investigators concluded that refrigerating blood samples in either red-, purple-, or green-top tube was suitable for the accurate simultaneous determination of both COHb and MetHb, if the analytes are measured immediately after collection or after two weeks of storage. Given that the nature of post-mortem forensic casework is such that suitable blood specimens are not always available for toxicological analyses, for the second aim of the study, the researchers sought to investigate the suitability of thoracic cavity fluid as an alternative specimen for the measurement of COHb. For this aim, thoracic cavity fluid collected into green-top tubes from the aforementioned cases was analysed immediately after collection. The results were compared to those obtained from the analysis of blood collected into green-top tubes and analysed on day zero (before storage). The statistical analyses used for this assessment indicated that thoracic cavity fluid would be a suitable alternative to blood for the measurement of COHb using the ABL825 FLEX analyser.
  • No Thumbnail Available
    Item
    Open Access
    The development and validation of an ABL835 FLEX Blood Gas Analyser method for the quantitation of glucose, lactate, and electrolytes in post-mortem vitreous humour
    (2025) Van Vuuren, Andrew; Mader, Jade; Khotseng, Mmitsane
    Post-mortem biochemistry provides valuable insights into the biochemical status of an individual at the time of death. Vitreous humour (VH) has an anatomically isolated location within the body, making it less prone to the effects of putrefaction and autolysis after death. As such, VH has frequently been described as the specimen of choice in biochemical forensic investigations to identify potential ante-mortem conditions and to estimate the post-mortem interval. The lack of a validated method for post-mortem biochemistry analysis using VH as part of routine toxicology testing within the Western Cape province of South Africa motivated the primary aim of this study, which was to develop and validate a method for the analysis of glucose, lactate, and electrolytes (potassium (K+), sodium (Na+), chloride (Cl-) and calcium (Ca2+)) using an ABL835 FLEX blood gas analyser. Method development included instrument verification and sample preparation optimisation, which assessed the effect of centrifugation and dilution. Validation included tests for accuracy, precision, sample stability, drug interferences and between-eye differences. Sample preparation experiments determined that untreated VH may be analysed directly or diluted in a 1:1 ratio with ultrapure water, when required. All analytes demonstrated acceptable bias, within-run and between-run precision at concentrations above 1.6 mmol/L. Results indicated suitable stability for K+, Na+, Cl-, glucose and lactate across all storage conditions over 31 days, while Ca2+ values decreased over time when frozen at -20°C. Drug interference was minimal for most analytes, with effects remaining within acceptable ranges (%error < ± 20%), with the exception of Ca2+. No statistically significant between-eye differences (p > 0.05) were observed for any analytes in both undiluted and diluted (1:1) samples. Overall, the method performed satisfactorily and was deemed fit for purpose for routine analysis. While important limitations regarding sample stability and potential interferences must be considered, this method provides a valuable resource for post-mortem biochemical analysis in cases of unnatural deaths in the Western Cape to support both individual case resolutions and broader public health insights.