Open-access UPLC

<p>Hi all,</p><p></p><p>We installed an UPLC-PDA-SQD system equipped with a Sample Organizer to be used in Open-access format by Medicinal Chemistry Department last October. </p><p>Since then, the system worked accurately but in the last couple of months, it has presented intermittent sensor adjustments problems that at the end have been successfully resolved by Waters engineers. But now, the confidence of Medicinal chemists with UPLC is not very high.</p><p>I would like to know if someone in the community can share with us their experiences in the use of UPLC system as an open-access: number of injected samples, main encountered issues, reliability of the instrument, number of systems, time that you have been using UPLC as open-access system, and any ideas that you can think that can be of interest.</p><p></p><p>Thanks to all of you,</p><p></p><p>Josep.</p>


  • Hello,

    We use UPLC in an Open Access Medicinal Chemistry environment.

    We have a similar system to yours, but its an Waters Acquity “Open Architecture” system, rather than an Acquity with a sample organiser.

    We did look at the sample organiser before we bought our UPLC, but we felt that the Open Architecture System (with the open bed 2777 auto-sampler) would be more suited to Medicinal Chemistry use.

    We have PDA, SQD, ELSD as well as the 4-position column manager on there.
    The 2777 injector has an open bed capacity for near 300 vials, as well as a Stack for 6 Deepwell Plates (or extra vials if desired).

    We have not been disappointed, as the system has proved very reliable and flexible.

    Chemists like the fact that they can place/remove the vials from an open bed rather than having to open doors, find plate positions etc.

    Number of injected samples: 100 to 200 per 24 hours (we run at night as well).

    Main encountered issues: Not much.
    The odd software glitch, overpressure, syringe needle blockage – but not much else.

    Reliability of the instrument: I would say “very”.

    Number of systems: 1

    Time that you have been using UPLC as open-access system: 1.5 Years

    Any ideas that you can think that can be of interest:

    We use a 3 different columns and 2 different pH’s to ensure maximum flexibility & orthogonality.

    We use Vanguard Pre-columns, and flush each column with acid mobile phase & DMSO/formic acid injections each morning to regenerate the columns.
    This seems to remove quite a bit of reaction mixture “junk” from the columns as peak shape, if deteriorated, is usually restored.

    Chromatogram run times are 1.5mins for Reaction Monitoring,  5 mins for a QC run.

    ELSD can be useful for compounds with no chromospheres.