A Parallel Three Column System and Direct Pooling of Samples in one Minute: Especially Suitable for in Vitro Screens

摘要

Possibility to pool two samples directly in the injection needle and analyse in 1.6 minutes with good precision (CV 8.7 percent) and low carry over (less than 0.8 percent). The wash cycle of the autosampler and the dead volume of the gradient pump set the limit for the analysis time. About 600 samples can be analysed over night on a single instrument. Hydrophilic compounds like salts and ion suppression agents like MES and HEPES can easily be switched to waste (avoid going to MS). More hydrophobic agents, like PEG, eluting later and thus more difficult to separate from the compounds analysed. The separation can be improved with a longer gradient. With a 3.2 minutes time window it was possible to separate PEG from the compounds analysed.