Acquity injection modes

<p><span>Hi,</span></p><p><span>I'm trying to understand how the various injection modes work with the Acquity Sample Manager.</span></p><p><span>Going through all the information I have on the sample manager I know there are 3 injection modes (PLPA, PLUNO, FL). </span></p><p><span>I know how each mode positions the sample differently in the loop and that </span><span>there is an injection procedure of:
1.) Aspiration of Sample</span></p><p><span>2.) Pressurization of Sample</span></p><p><span>3.) Metering of sample into loop</span></p><p></p><p><span>Is this the same procedure for all injection modes? Do all modes use pressure assisted sample injection or is this limited to Partial Loop Pressure assist?</span></p><p><span>Are there any animations showing the different injection modes available online anywhere?</span></p><p></p><p><span>Thanks</span></p><p><span>Simon</span></p>


  • lizh

    Hello Simon:

    Pressure assist is used with Partial Loop with Pressure Assist (PLPA) and with Full Loop modes. It is not used with PLNO mode. Pressurization is helpful in reducing the differential in pressure between the loop (at atmospheric) and the system (at the higher operational pressure).

    Partial loop uses needle overfill (PLNO),the default injection mode of the ACQUITY UPLC Sample Manager. The sample is injected with an additional buffer pf sample which serves to reduce the amount of analyte lost by adsorption to the internal surface of the sample needle, pressurization is not used in this case.

    In the Overview page, under Educational webcasts you will find "Injection Mechanisms", this links to a representation of the injection modes and sample positioning. Also the injections mode quick reference document also posted in the overview is useful and I have attached here to save time.

    If you have any further questions after reviewing this let us know.

    Best regards,


  • SNoble

    Thankyou for the reply. It has clarified what I was confused about and the link to the injection techniques movie was very helpful.