In the second part of this interview with Maria Olds of the University of Texas at Arlington, she discusses the consequences of not accounting for preanalytical factors in blood alcohol concentration (BAC) analysis.
Forensic science is used for a variety of purposes from enforcing criminal law to protecting public health (1). It is now standard practice to use advanced forensic techniques, such as fingerprinting, DNA testing, and more, when assessing physical crime scenes (2). These techniques are improving how crimes are solved in the field. Maria Olds of the University of Texas at Arlington is one of these researchers.
Maria Olds is currently a PhD candidate at the University of Texas at Arlington in the chemistry department under advisor Daniel W. Armstrong, studying chromatography with a focus on chiral separations. Prior to returning to academia, Olds worked as a chemist for 17 years, specializing in gas chromatography-mass spectrometry and forensics. She initially worked in research and development at MRIGlobal (previously Midwest Research Institute) in Kansas City, and more recently worked for the Fort Worth Police Department Crime Laboratory as a seized drug analyst and blood alcohol toxicologist. Olds received a master of science in forensic toxicology from the University of Florida, and has authored six publications, five of which are related to blood alcohol concentration determination, and two of which are co-authored by Alan Wayne Jones of Indiana University Bloomington and the National Board of Forensic Medicine in Linköping, Sweden (3).
Olds’ recent research has focused on preanalytical effects that can impact ethanol analysis in blood and urine samples. These conditions, such as potential contamination and time elements, can make it difficult to properly analyze and quantify ethanol in the system.
In part two of our interview with Olds, she discusses the consequences of not accounting for preanalytical factors in blood alcohol concentration (BAC) analysis. Additionally, Olds suggests what other forensic scientists should take away from her work and apply to their own research.
What are some of the consequences of not considering pre-analytical factors for blood alcohol content analysis?
There are dire consequences if no considerations for pre-analytical factors are made. We're lucky that we live in a world where considered pre-analytical factors are significantly considered.
Review articles typically include the method by which the sample is taken, so sterile collection of samples, and it also includes the preservation conditions of samples. And so, if no consideration for these preanalytical factors were made, the samples could theoretically be contaminated with microbes. Microbial contamination of samples has been demonstrated to generate ethanol in certain cases where samples were inoculated with different types of microbes.
It’s also really important to consider the differences between antemortem and postmortem samples, because in postmortem samples you could have microbial generation of ethanol due to the nature of decomposition of the body.
You have to consider different levels of preservatives that are relevant and specific to the type of analysis that you're doing. Antemortem samples, or samples that are collected from a living person, don't necessarily require as much preservative as a sample taken from a deceased person. Specifically, a sample taken from a deceased person would require 1 to 2% of sodium fluoride or potassium fluoride preservative.
What's nice about working in forensics that I really enjoyed was that pre-analytical factors can be detected by any part of the criminal justice system itself. So, there are forensic practitioners, and we often discuss pre-analytical factors.
At our workplaces or at conferences, pre-analytical factors also get discussed in court by both the prosecution and the defense. Both sides definitely want the highest quality samples that can be maintained and the highest level of testing that can be achieved. Concerns can always be expressed academically or intellectually by academia or by any interested party.
Are there any plans to expand upon your current findings?
For the next two to three years, I'll be completing my PhD in chemistry at the University of Texas in Arlington. Some of that research that I'm doing does tie back into forensic work specific to blood alcohol. I have a few ideas up my sleeve that Doctor Alan Wayne Jones (Indiana University Bloomington) and I talked about a few years ago with regards to ethanol testing. So, sometime in the future there will be more follow- up full alcohol studies from myself.
Using the findings from this research, what further actions can other researchers take when looking at different parts of BAC analysis?
It's not specific to BAC analysis, but some good advice that I received when I was getting my master's degree was that it's important to limit your scope of study. A lot of these blood alcohol articles that are summarized in the two review articles that we wrote is that they all focus on one specific aspect of the blood alcohol testing procedure, and the procedure can differ from lab to lab. So, it's important to focus in on the question at hand. Next, design your experiment to test just that one specific question, then eliminate any potential confounding factors so that you have a high level of confidence in your result.
Was there anything that surprised you about this research that our readers should know?
I hate to answer that question, because I just think there should always be something that surprises you when you're researching such a large topic. But most of the articles that we reviewed, they follow a logical thinking path, and the result that they got makes sense in the end.
I will say, one thing that surprised me is that a lot of the historical studies were conducted. In 1975, there was a train crash in England called the Moorgate train crash, and in that crash, it was questioned whether the conductor had been under the influence of alcohol. What's nice is they did an extremely thorough series of studies to demonstrate that alcohol could be generated by different microbial entities in the gut, and a lot of those studies came about because of the tragic event.
There was also another tragic event on the USS Iowa later in 1989. That's another example of the context of the potential of blood alcohol being generated post-mortem being really critical. It was important in that instance to evaluate multiple different tissue samples for bodily fluid samples, to determine whether the ethanol had been ingested or was generated after death. In many of the instances at the USS Iowa, the ethanol was actually generated after death, and that was supported by alternative bodily fluid samples.
To watch the first part of our interview with Olds, click
(1) What is Forensic Science? American Academy of Forensic Sciences 2025.
(2) The Role of Forensics in Modern Criminal Investigations. Northwest Career College 2025.
(3) Jones, A. W.: Robert F. Borkenstein Courses. Indiana University Bloomington 2025.
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