Older GCers, of course that doesn’t include me, have seen an instrument evolution leading us from µg to fg or even sub-fg analyses. Detecting lower amounts often comes with a significantly increased price tag for the instrument. Sophisticated GCers (can I put myself in that category, or did I lose credibility when I eschewed the “old” moniker?) know that when you have a high-horsepower detector you must still pay attention to the GC, i.e. your expensive MS ain’t gonna see any fgs or pgs if the inlet liner and column are not high-performers also. But how many of us go further upstream to guarantee success? I’m talking about the (relatively inexpensive) autosampler syringe.
In an ongoing melamine analysis project where my sample is pyridine:BSTFA, my “usual” autosampler-syringe wash-solvent, acetone, was not providing a proper wash, and the syringe was fouling, leading to poor sensitivity and wildly irreproducible results. A switch to toluene fixed the problem! More later.
Further reading: Agilent Autosampler Syringes
