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Large volume splitless injection WITHOUT a PTV!

30 Nov 2009


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Recently while trying to create backflash in an Agilent splitless injector, I noted linear compound responses as I injected up to 25µL for PAHs from naphthalene to benzo(ghi)perylene! I went to the literature (note to self: start with the literature) and found papers from Magni and Porzano, and Grob’s group, where they termed the technique “Concurrent Solvent Recondensation Large Sample Volume Splitless Injection”.

Here are my suggested considerations for large volume splitless injection on an Agilent injector: (1) 4mm single gooseneck liner with wool at bottom, (2) 5m x 0.53mm retention gap press-fitted to analytical column, (3) fast autosampler injection (6000µL/min) at 250°C of a relatively NON-POLAR solvent, (4) oven temperature start below the boiling point of the solvent, (5) purge valve time that transfers most non-volatile analyte completely.

I subsequently used this approach to determine pesticides in dietary supplements (see figure for example).

Further reading: Concurrent solvent recondensation large sample volume injection, Magni and Porzano