In this blog, we go through these steps and provide an example of proceeding from the idea – detecting volatile products of microbial reactions to pilot – detecting volatile fatty acids (VFAs) in headspace to study – the SynbioPro project that we’re happy to be a partaking in! In this first post, we’ll go trough the planning phase of our pilot studies. In part two we’ll take a deeper look into the practical aspects of conducting a pilot study with the IonVision!
Before the description of the pilot study, we’ll look at the things to consider when planning one. With each potential use case, we have four questions that should be answered before proceeding to a pilot study. In short, they include defining the problem, the optimal solution, the theoretical background, and the requirements of the application.
A problem that could be solved with the use of DMS is a process where the products or byproducts are known, but no solution for the detection yet exists. The challenge could also lie in the reliability, ease, affordability and/or convenience of the current solution.
The VFA example is quite typical in this sense. Our idea for the pilot came from looking into the production of biofuels by fermentation. The goal of the process is to produce VFAs (materials for oil-based bioproducts). The key molecules are known, but a real-time detection method is yet to be implemented. Next, we need to consider how will the DMS be utilized in the process.
DMS can provide real-time or near real-time information of the problem depending on the needs of the user. This is especially important in cases where action is needed as soon as the chosen volatile organic compound (VOC) of interest is detected.
The portability of the technology also makes it possible to do measurements on different locations, without the need to take samples back to a laboratory. Many of the same molecules that would usually require mass spectrometry can be detected without the considerable sample preparation effort and high costs of MS.
In our example, DMS could be used to follow the production of VFAs in real-time. This would give information for the process overseer (or an automated system!) to adjust at the right time to maintain bacteria viability and keep the process under control and producing the wanted compounds.
After coming up with a flashy solution for a detection problem, we do still need to consider what and how are we going to proceed with a pilot. What are the compounds we want to see? Are they able to be detected with DMS? Is the problem quantitative or qualitative? Literature research is done to find answers to as many of these questions as possible.
One key quality of the molecule for DMS detection is its proton affinity. In short, if we want to be able to detect it in air, the molecule’s proton affinity needs to be higher than water’s. This is because water in the air forms the reactant ions for the DMS!
Lastly, we need to consider if the problem is quantitative, semiquantitative or qualitative. Coming back to the VFA example, we can consider the problem semiquantitative as we’re not interested in the exact concentrations, but the changes and proportions to previous measurements. Relevant molecules and their typical concentrations in the process were found in earlier research, and the found proton affinities seemed suitable for DMS. We could proceed.
After we’ve determined if the application is viable in theory, we still need to consider the practical aspects. Are the compounds safe to use in a pilot? How would the DMS system be implemented to the system in the final application? These things should be considered before forging ahead to the pilot study to make sure that the application is viable.
In the case of the VFAs, the things of note were the personal protective equipment requirements for working with concentrated acids. In cases of toxic or highly flammable (or extremely expensive, as is the case with some biological compounds) chemicals, we always consider if there would be a way to test the identification with some mixture or diluted samples. This is to avoid hazardous working conditions.
The part two of this blog is now up! There we continue on to the description of a typical pilot study. We’ll also tie the VFA project in with the SynbioPro project. You can read the second part here.