User manual

Agilent 1260 Infinity High Performance Autosampler User Manual 11

Introduction

Overview of the Module

The Autosampler transport mechanism uses an X- Z- theta robot to

optimize the positioning of the sampling arm on the well plate. Once the

sampling arm is positioned over the programmed sample position, the

programmed sample volume is drawn by the metering device into the

sampling needle. The sampling arm then moves to the injection position

where the sample is flushed onto the column.

The Autosampler employ a vial/plate pusher mechanism to hold down the

vial or the plate while the needle is drawn back from the sample vessel (a

must in the case a septum is used). This vial/plate pusher employs a

sensor to detect the presence of a plate and to ensure accurate movement

regardless of plate used.

All axes of the transport mechanism (x- ,z- ,theta- robot) are driven by

stepper- motors. Optical encoders ensure the correct operation of the

movement.

The standard metering device provides injection volumes from 0.1 –

100 µL. The entire flow path including the metering device is always

flushed by the mobile phase after injection for minimum internal

carry- over.

An additional needle flush station with a peristaltic pump is installed to

wash the outside of the needle. This reduces the already low carry- over

for very sensitive analysis.

The bottle containing the mobile phase for the wash procedure will be

located in the solvent bottle cabinet. Produced waste during this operation

is channeled safely away through a waste drain.

The six- port (only 5 ports are used) injection valve unit is driven by a

high- speed hybrid stepper motor. During the sampling sequence, the valve

unit bypasses the autosampler, and connects flow from the pump to the

column directly. During injection and analysis, the valve unit directs the

flow through the autosampler which ensures that the entire sample is

injected onto the column, and that the metering unit and needle are

always free from sample residue before the next sampling sequence begins.