Large Volume Splitless Injection for EPA Method 8270 Semivolatiles without a PTV and without a Press-Fit Connector for the Retention Gap

Regular readers (and maybe irregular readers, too) may remember several blogs I’ve posted on Concurrent Solvent Recondensation Large Volume Splitless Injection (CSR-LVSI) with an off-the-shelf split/splitless injector on an Agilent gas chromatograph.  Michelle Misselwitz and I recently made a major discovery on this work, confirming that gas chromatographers can make large volume splitless injections up to at least 12.5µL onto 0.25mm retention gaps connected to 30m x 0.25mm x 0.25µm analytical columns.  The nice part about this finding is that Restek has integrated guard columns on some of their GC column offerings.  That is, the guard column (a retention gap, in this case) is built in and no press-fit or other column connector is used.  We call it Integra-Guard.

We applied CSR-LVSI (with a 10 µL injection) to the analysis of semivolatile compounds from EPA Method 8270 and achieved excellent chromatography, with no backflash, for even the most volatile compounds, like NDMA and pyridine (see chromatogram below).

This opens the door for labs to stop their extract evaporations short, diluting samples to 10 mL and injecting 10 µL, instead of going to 1 mL and injecting 1 µL.  Evaporative losses of volatile compounds like NDMA, pyridine, dichlorobenzenes, phenol, naphthalene, etc., will be minimized, and switchovers from macro Snyder column assemblies during Kuderna-Danish evaporation to micro Snyder columns can be eliminated.  For busy environmental labs, I call this concentrating money instead of concentrating samples.   

I will be presenting this work at PittCon 2011 in Atlanta, Georgia in just a few weeks.

Large Volume Injection for Gas Chromatography Using a Commercially-Available, Unmodified Splitless Injector, GC-MS Methods for Environmental Issues, Wednesday Afternoon, March 16, Room 404

Check below the figure for additional reading.

 

Large Volume Splitless Injection of EPA Method 8270 Semivolatile Compounds

Other blogs on large volume splitless injection:

The Solvent Effect in Concurrent Solvent Recondensation Large Volume Splitless Injection with Methylene Chloride – EPA Method 8270 Semivolatiles

Large volume splitless injection WITHOUT a PTV!