A new development in HPLC–MS is presented, whereby the speed of the analysis is essentially equivalent to direct injection protocols applied in analyses using MS alone.
The key to achieve these ultra-high through-put assays
is the employment of a newdesign in HPLC columns referred to as active flow technology.
Active flow technology HPLC columns enable the radial central portion of the flowto be sampled fromthe columnand directed to
a detector.
This is themost efficient region of the solute migration, free fromwall effects. In this study the internal
diameter of the active technology column was 2.1 mm, the flow rate was 4.5 mL/min and 21% of this flow was
sampled from the radial central region of the column; thus the flow to the MS detector was just 0.9 mL/min.
The injection to injection cycle timewas 24 s, comprising a 6 s period for the injector itself and an 18 s separation
of 10 amino acids.
The study presents details of the injection to injection reproducibility in this analysis,
highlighting the substantial benefit of being able to undertake ultra-high through-put HPLC–MS.