The high-flow infusion technique uses a union Tee to direct the solvent flow from the syringe pump into the solvent flow produced by an LC pump. The combined solvent flow goes through the divert/inject valve into the API source. Use this infusion method to perform experiments at a higher flow rate with an LC system. The high-flow infusion method allows you to optimize the source parameters (such as sheath gas and vaporizer temperature) at the flow rate and mobile phase composition of the assay.

When the divert/inject valve is in the 1–2 (Load) position, solvent flow from the LC pump enters the valve through port 2 and exits the valve through port 1, which connects to the API source. When the divert/inject valve is in the 1–6 (Inject) position, solvent flow from the LC pump enters the valve through port 2 and exits the valve through port 3 to waste.

The following figure shows the high-flow infusion plumbing diagram using the optional divert/valve.

Figure High-flow infusion plumbing diagram
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No.DescriptionNo.Description

1

From LC pump

4

To API source

2

To union Tee

5

To waste

3

Union Tee to divert/inject valve (port 2)

6

Union Tee to divert/inject valve (port 2)

 

Required Materials

  • Divert/inject valve (not provided)

Prerequisites

  1. Set up the syringe and syringe pump. See Set up the Syringe.

Procedure

  1. Connect red PEEK tubing from the LC pump’s outlet to the union Tee using a two-piece fingertight fitting.
  2. Connect red PEEK tubing (the infusion line) between the LC union and the union Tee using two-piece fingertight fittings.
  3. Connect red PEEK tubing between the union Tee using a two-piece fingertight fitting and the divert/inject valve (port 2) using a one-piece fingertight fitting.
  4. Connect red PEEK tubing between the divert/inject valve (port 1) using a one-piece fingertight fitting and the spray insert's sample inlet using a two-piece fingertight fitting.
  5. Connect Teflon tubing to the divert/inject valve (port 5) using a Rheodyne fitting. Then, connect the remaining end into an appropriate waste container.