User manual

Agilent 1260 Infinity High Performance Autosampler User Manual 13

Introduction

Autosampler Principle

The movements of the autosampler components during the sampling

sequence are monitored continuously by the autosampler processor. The

processor defines specific time windows and mechanical ranges for each

movement. If a specific step of the sampling sequence is not completed

successfully, an error message is generated. Solvent is bypassed from the

autosampler by the injection valve during the sampling sequence. The

needle moves to the desired sample position and is lowered into the

sample liquid in the sample to allow the metering device to draw up the

desired volume by moving its plunger back a certain distance. The needle

is then raised again and moved onto the seat to close the sample loop.

Sample is applied to the column when the injection valve returns to the

mainpass position at the end of the sampling sequence.

The standard sampling sequence occurs in the following order:

1 The injection valve switches to the bypass position.

2 The plunger of the metering device moves to the initialization position.

3 The needle lock moves up.

4 The needle moves to the desired sample vial (or well plate) position.

5 The needle lowers into the sample vial (or well plate).

6 The metering device draws the preset sample volume.

7 The needle lifts out of the sample vial (or well plate).

8 The needle is then moved onto the seat to close the sample loop.

9 The needle lock moves down.

10 The injection cycle is completed when the injection valve switches to

the mainpass position.

If needle wash is required it will be done between step 7 and 8.