Chromatography Forum

Hello all!

I am working with a PE Clarus 600 GC/FID (Column: CP-Sil 19 CB) to develop some quantitation methods for species at lower concentrations (< 100 ppm). I was not involved with purchasing this instrument, so I currently do not have an idea of the manufacturer's specifications for what to expect as the limits of detection or quatitation (I've requested this information from PE...waiting to hear back).

I assume this will vary greatly depending on the species involved, but as a starting point, I was wondering if anyone out there has experience in this instrument's capabilities?

I appreciate any input!

Thanks,
EZchem

You are correct. As with any analytical method that can determine more than one substance, the detection/quantitation limits are very analyte dependent. You'll just have to determine them for yourself with your system in your matrix.

Thanks! I did some more sifting through past posts and found that as a rule of thumb, I need to test my specific analyte/system. Limit of detection should be 3:1 S/N, and limit of quantitation should be 10:1 S/N.

Still waiting to hear back from PE though (boss wants a hard number as a reference...).

The detection limit depends totally on your specific application. I have developed several Methods where the detection limit is below 1 ppm for several components, using Liquid Injection or Headspace.

You need to determine the detection limit yourself, preparing standard solutions with known concentration and find out "how low can you go". I dont think that you will get a definite answer from Perkin Elmer on that.

With an FID you should get small, but decent peaks from 0.1.ng of the usual GC-FID analytes. So you can calculate back to your original sample by taking into account the split ratio, injection volume, volume in the vial, concentration / extraction and mass or volume of sample.

Peter