Flow scheme of LH 2.1
The needle wash is performed after each injection. To flush the whole tubing from the dispenser syringe to the injection valve (buffer tubing) and furthermore from the injection valve to the needle (needle tubing), the needle wash volume should be at least the sum of buffer tubing and needle tubing volume. Per default, the needle tubing is 8.1 mL and the buffer tubing is 21 mL but this can differ according to changes done during device installation and maintenance.
In special cases, the needle wash volume can be decreased to the volume of the needle tubing. This is especially the case when sandwich supply is chosen as dead volume type and the same eluent type is used as wash solvent and as a sandwich solution.
