Macademics : ESI-Mass Spectrometry
Welcome to our Macademics Series! We decided to bring some practical STEM knowledge to our readers. Every first Thursday of each month, each of us will pick a topic, article, new technology, etc, in our fields and tell you about it. We hope you guys enjoy it.
Since I'm the one in graduate school, I decided to start off my series with the technique that my research is based on, electrospray ionization mass spectrometry (ESI -MS). I won't get into too many details - because that would be too much to read on a single blog post - but I'll give a general overview of how it works and what I'm using it for.
First things first, what is mass spectrometry? It's a technique that detects and sorts the mass to charge (m/z) ratios of molecules. There are many different types of detectors, analyzers, ionization sources, etc. in the mass spect world, but I'm only going to focus on this one - ESI is just the way we charge the species we're analyzing (ionization process).
I added a schematic of the setup of ESI for all of my visual learners out there. But here's the basics...
1. There's a capillary tube (normally) that holds the solution.
2. The solution is made up of the analyte (thing you want to detect) and a spray solvent (thing that carries the analyte to the mass spect and aids in ionization).
3. You have to add voltage to the capillary so you can ionize the solution.
4. Adding the voltage creates an electric field that causes the Taylor Cone at the tip of the capillary which shoots out charged droplets.
5. As the droplets are moving towards the mass spect, the solvent starts to evaporate and transfers the charge to the analyte, which enters the detector.
6. Analysis happens and you get a spectrum that is sorted by m/z which we use for identification and quantification of our analyte(s) of interest.
Hopefully that made sense to my non-scientsits, but if you want to learn more about the fundamentals check this out: https://en.wikipedia.org/wiki/Electrospray_ionization
Now, a sneak peek into my research. My goal over the course of the next 4.5 years is to develop a method to analyze illicit drugs in biofluids (blood, urine, serum, etc.) using ESI-MS. There's just a trick, instead of using just a capillary to charge the drugs, I'm using thread as my ionization platform. I,personally, think it's pretty cool, so be on the lookout for more information as I continue my research and we start publishing papers!
ESI-MS is a widely used technique in the MS world because of it's sensitivity, selectivity, minimal sample consumption and preparation. If you're interested in learning about the vast amounts of applications using ESI-MS or MS in general, shoot us an email and I'll be happy to answer any specific questions.
See you at our next Macademics session.