Interview with Sarah Wille

Sarah Wille

Judicial Expert Forensic Toxicologist
National Institute of Criminalistics and Criminology
Brussels, Belgium


In March we celebrate the achievements of women, so it’s lovely that we have an exceptional woman responding our interview this month. Sarah Wille is a Judicial Expert Forensic Toxicologist, a specialist area of toxicology we don’t often hear from in our interviews. Sarah has been involved with our Young Scientist committee and is also very active with our sister association, TIAFT. Another great interview this month, read on…


Can you tell us a little bit about your respective roles? What is a typical day like for you?

Since 2008 I work as a certified Judicial Expert Forensic Toxicologist at the National Institute of Criminalistics and Criminology (NICC) in Brussels, Belgium and this.

The NICC is the Belgian central authority on forensic research and has two main missions. First, it realizes forensic analyses on demand for judicial authorities, in the criminalistic domains of genetics, biology, analytical chemistry, drugs, toxicology, ballistics, and digital information and cybercrime. Second, it conducts scientific studies on crime phenomena to inform criminal policy. Topics of research include police and judicial investigation, prosecution policy, penalty enforcement, juvenile delinquency, etc.

My basic training was Pharmaceutical Sciences (2002), followed by a PhD in Analytical Toxicology at the Forensic laboratory at the Ghent University under the auspice of Prof. Willy Lambert (2008). This gave me the ideal training for my current job.

A day at our laboratory can vary enormously. My main role is to give expert advice for the judicial authorities (this is case work according to ISO 17025 standards), but this role is more complex than it sounds. It consists of managing the analytical laboratory procedures, following up the quality assurance of the analysed batches and helping with troubleshooting in the laboratory, making the expert reports and if requested testifying in court. This of course requires adequate people management to help coordinate the laboratory. A second task is to give courses in forensic toxicology, mainly to the police and judicial authorities. Providing support to other government organizations dealing with drugs and informing the general public is one of our core tasks as well. Finally, another big part of my role is keeping up with novel techniques by doing scientific research in collaboration with external partners and implementing this research in the laboratory to ameliorate our services. As a senior researcher at the Toxicology Unit of the NICC, my main research topics include new psychoactive substances (NPS), alternative matrices, entomo-toxicology, and analytical method development/validation.

On the side, we edit the TIAFT Bulletin since 2016 and occasionally organize a scientific meeting such as the international TIAFT meeting in 2018 in Gent, but also workshops for Young Scientists (TIAFT) from 2009-2019.

Is there anything that your laboratory does, or that is done at your institution that you would consider innovative?

Our laboratory does not do fundamental research. However, we try to keep up with new trends, techniques, biomarkers, to make our judicial advice as up to date as possible. Where we can, we create research projects or collaborate with universities to solve problems we see in routine casework or resolve unsolved questions via research. In this regard, we have contributed to validation-guidelines (1,2), have looked into new toxicological matrices such as the use of oral fluid (3-7) and insects (8-10) and have collaborated to improve the knowledge database and detection of New Psychoactive Substances (NPS; 11-14). Moreover, we have established a uniformed way to detect the ethanol marker phosphatidylethanol for driver’s license regrating procedures (15). We also implement innovative management concepts such as LEAN and self-managing teams into our laboratory environment.

What technological innovations have entered into use during your career that have permitted a change, or evolution, in practice?

High Resolution Mass Spectrometry has been life changing as it enables us to do a fast, sensitive and selective screening of our samples. The main advantage is that we are able to detect NPS in our laboratory.

How did you become interested in your area of expertise?

I always wanted to work as a scientist. However, my first idea was to become a marine biologist in [Jacques] ‘Cousteau’ style (the French Marine Biologist diving into the deep sea). However, several people convinced me to start Pharmaceutical Sciences as there are a lot of research opportunities in pharmaceutical sciences in Belgium. At the end of my studies, the scientific investigator in me awoke again and I wanted to look into the options of analytical chemistry, but in a very practical way and with societal importance.

Is there anything that you’ve seen or heard about recently and thought “I’d like to incorporate that idea at my center”?

There are so many things I would like to incorporate in our laboratory if time would let us. Some of these include:

  1. application of artificial intelligence or machine learning to get a better grasp on the ever-increasing databases,
  2. looking into a practical approach to gain more information about genotype/ phenotype detection and its interpretation for casework, and
  3. the detection of biomarkers in oral fluid and other matrices to improve drug detection and interpretation are surely on the priority list.

What sort of research do you have on the horizon that you think might influence clinical practice in the future?

Over the last decades, bio analytics has gone through a period of extensive change driven by technological advances. Due to the development of highly sensitive techniques, the use of alternative matrices or alternative sampling in the field of toxicology has increased enormously.

While blood and urine are still the most common applied toxicological matrices, alternative matrices such as oral fluid (OF) have gained importance. OF can be applied to detect recent drug use and is of interest because the collection can be more advantageous: a non-invasive collection and less possibility for adulteration. We would like to look more into the possibilities of a fast and more selective on-site screening of large batches of oral fluid samples as well as establish biomarkers that can improve the interpretation or look into the ‘quality’ of the obtained sample for analytical confirmation techniques.

Another field of research is the further implementation of micro sampling techniques such as dried blood spots, volumetric absorptive sampling devices, etc. to improve sampling via non-medically trained personnel and improve stability of certain compounds.

What do you consider is the future for TDM and CT? What are you excited about? What are the challenges we face?

Toxicology, and forensic toxicology in particular, has faced many challenges for many years, both analytical and interpretative, especially in relation to an increase in potential drugs of interest. However, as a result of research and technological advancements, we may be closer to solving some of these challenges and discovering new ones. The development of highly sensitive detection techniques and appropriate data processing has enabled the analysis of a wide range of compounds, now in a wide range of matrices. This includes the identification of new toxicologically relevant markers and greater understanding of the role of pharmacokinetics and pharmacodynamics to assist with interpretation of toxicological findings.

It is clear that the future of toxicology will be multi-disciplinary and utilise developments in information technology along with statistics to provide possible solutions to interpretation of large data sets and scenarios to the benefit of medical or judicial decisions. Someday we may be able to utilise the detection of drugs, metabolites and biomarkers in multiple matrices in conjunction with genetic information and other parameters to interpret the significance of the findings in both in life and post-mortem situations. We will get there by continued collaboration and research in toxicology with a view to developments in other disciplines and use of technological advances and innovations.

We may not be there yet, but we are heading in the right direction. And whilst certainty may never be achieved, we will be more aware of possible sources of uncertainties and thus be able to constantly but steadily improve our final outcome.

How has COVID-19 affected your professional life?

COVID-19 has had an enormous impact. The amount of casework has increased enormously, and this is combined with less people in the laboratory as we have to maintain distance and work at home as much as possible. Getting a team running and informed all the time, while not seeing each other as much is difficult, but is manageable via all kinds of video conferencing tools. One thing for me, that was the hardest was to combine work-life with two small children at home. Juggling with work-life balance has been harder than ever; luckily there is support at home.

  1. Update of Standard Practices for New Method Validation in Forensic Toxicology. Wille SMR, Coucke W, De Baere T, Peters FT. Current Pharmaceutical Design 2017, 23:5442-5454.
  2. Practical aspects concerning validation and quality control for forensic and clinical bioanalytical quantitative methods. Wille SMR, Peters FT, Di Fazio V, Samyn N. Accreditation and Quality Assurance 2011, 16 (6): 279-292.
  3. Roadside drug testing: comparison of two legal approaches in Belgium. Van der Linden T, Wille SMR, Ramírez-Fernández M, Verstraete AG, et al. Forensic Science International 2015, 249:148-155.
  4. Trends in drug testing in oral fluid and hair as alternative matrices. Wille SMR., Baumgartner MR, Di Fazio V, Samyn Nele, et al. Bioanalysis 2014, 6 (17) p. 2193-2209.
  5. Evaluation of Δ9-tetrahydrocannabinol detection using DrugWipe 5S® screening and oral fluid quantification after Quantisal collection for roadside drug detection via a controlled study with chronic cannabis users. Wille SMR, Di Fazio V, Toennes SW, van Wel JHP, et al. Drug Testing Analysis 2014, 7(3):178-86.
  6. Driving under the influence of cocaine: quantitative determination of basic drugs in oral fluid obtained during roadside controls and a controlled study with cocaine users. Di Fazio V, Wille SMR, Toennes SW, van Wel JHP, et al. Drug Testing Analysis, doi: 10.1002/dta.2379.
  7. Driving under the influence of cannabis: pitfalls, validation and quality control of a UPLC-MS/MS method for the quantification of tetrahydrocannabinol in oral fluid collected with StatSure, Quantisal or Certus collector. Wille SMR, Di Fazio V, Ramírez-Fernández M, Kummer N, et al. Therapeutic Drug Monitoring 2013, 35:101-111.
  8. Methadone determination in puparia and its effect on the development of Lucilia sericata (Diptera, Calliphoridae). Gosselin M, Di Fazio V, Wille SMR, Ramírez-Fernández M, et al. Forensic Science International 2011, 209 (1-3): 154-159.
  9. Entomotoxicology, experimental set-up and interpretation for forensic toxicologists. Gosselin M, Wille SMR, Ramírez-Fernández M, Di Fazio V, et al. Forensic Science International 2011, 208 (1-3):1-9.
  10. Quantification of methadone and its metabolite 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine in third instar larvae of Lucilia sericata (Diptera: Calliphoridae) using liquid chromatography-tandem mass spectrometry. Gosselin M, Ramírez-Fernández M, Wille SMR, Samyn N, et al. Journal of Analytical Toxicology 2010, 34 (7):374-380.
  11. Semiquantitative activity-based detection of JWH-018, a synthetic cannabinoid receptor agonist, in oral fluid after vaping. Cannaert A., Ramírez-Fernández M, Theunissen EL, Ramaekers JG, Wille SMR, Stove CP. Analytical Chemistry 2020, 92:6065-6071, doi 10.1021/acs.analchem.0c00484.
  12. Activity-based reporter assays for the screening of abused substances in biological matrices. Cannaert A., Vandeputte M., Wille SMR, Stove CP. Critical Reviews in Toxicology 2019, 28:1-15, doi 10.10408444.2019.1576588.
  13. Activity-based concept to screen biological matrices for opiates and (synthetic) opioids. Cannaert A., Vasudeva L, Friscia M, Mohr ALA, et al. Clinical Chemistry 2018, doi: 10.1373/clinchem.2018.289496.
  14. Activity based detection of cannabinoids in serum and plasma samples. Cannaert A, Storme J, Hess C, Auwärter V, et al. Clinical Chemistry 2018, doi: 10.1373/clinchem.2017.285361.
  15. Quantitation of phospahtidylethanol in dried blood after volumetric absorptive microsampling. Van Uytfanghe K., Ramírez-Fernández M, De Vos A., Wille SMR., Stove CP. Talanta 2021,


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Sarah Wille