Ultra-high speed analyses of amino acids were undertaken using active flow technology chromatography columns with MS detection. The AFT columns employed here had internal diameters of 2.1 mm, and these columns were operated at 4.5 mL/min. Subsequently, separations of the amino acids were feasible in less than 15 s, with injection to injection precision generally less than 5%, dependent on the standard concentration. Because these AFT columns enabled very high flow rates to be employed with MS detection, high sample through-put was achievable that effectively emulated direct injection protocols.
The analyses in this study were subsequently based on ten replicates per standard (or sample) across five concentration standards, with two samples; the entire analysis being completed in less than 25 min (total number of injections being 60). This exceptional gain in analytical through-put, with the excellent level of precision that was obtained suggests that AFT columns coupled with MS detection should find widespread application in analytical laboratories that require high sample through-put.
Effectively, the study presented here shows that HPLC–MS, with AFT columns can operate with direct injection through-put, but with the benefits of a significant separation step.