Welcome to another episode
of Behind the Science, Rock Star edition. I’m your host,
Jennifer Fournier. A friend of mine got me into
listening to soft melodies, which play long notes. Interesting fact on long notes. Apparently, Kenny G
holds the Guinness record for holding the longest
note on a saxophone– an E flat for over 45 minutes. That is a long time. Holding long flowing notes
help create soft, smooth music. So in this episode of
Behind the Science, I want to tell you about
the soft ionization techniques for GC,
and how they’re useful in pesticide analysis. So let’s go meet our
version of Kenny G. Kari, how are you? Hi, Jen. I’m good.
How are you? Great. I’m glad I found
you, because I’ve been using some pest control
products around my home lately. And after learning
what pesticides can do to the bee population,
I want to make sure that I’m using a safe product. You’ve come to the right place. Actually, one of the
pesticides that’s found in a lot of home
pest control products is called Bifenthrin,
and it’s known to be harmful to
the bee population. And it can also be
a very hard compound to analyze using typical
electron impact gas chromatography. So how would you test for it? So we would use our
atmospheric pressure gas chromatography,
or APGC system, which I can show you right here. That’d be great. So, Jen, electron
impact ionization is an ionization process
where the compounds are being hit with high energy
electrons to produce ions. Since the compounds
are being hit, they tend to fragment
before entering into the mass spectrometer. Since the parent ion is no
longer intact for analysis, this can cause decreased
selectivity and sensitivity, leading to false positives. But we have a different solution
called atmospheric pressure gas chromatography, or APGC, that is a much softer ionization technique. APGC is a soft
ionization technique where the charge is transferred
to the compound from a corona discharge. By ionizing the compound
with a transfer mechanism, as opposed to impacting, the
compounds do not fragment. This generates an ion
on the parent molecule, rather than a fragment. The analysis is
much more selective and sensitivity is enhanced. Wow, Kari, that’s
really interesting work. I like what you are able to get with soft ionization techniques. But I have to tell you,
I still do a lot of work with electrospray ionization. Do I need a dedicated
system for APGC? No, using the APGC
source, you can actually do both APGC and ESI, or LC, on the same mass spectrometer. We have the set up here. I can show you how easy it is to switch over between the two. Yeah, let’s do it. I’m going to get out of the way. It’s really that simple. Wow, it really is that simple. But I don’t know if I
can be as fast as you. Now, I can add a new instrument that plays soft notes to our rock band. So if I want to gently ionize
a GC compound, I can use atmospheric
pressure gas chromatography. It creates fewer fragments
and increases the selectivity of the analysis. Plus, how great is it
that you can quickly swap out the source,
making it so versatile? And as promised, we have an
application note for this. Check out the link below
for more information on what we discussed today. And join us next time
for another episode of Behind the Science Rock Star.