Instant Notes: Analytical Chemistry

Autosamplers Autosamplers are used to enable a series of samples and standards to be taken
from pre-loaded vials and analyzed in sequence, normally under computer
control. They consist of a rectangular or circular array of sample vials in a rack
or turntable, and a means of transferring measured volumes to an analytical
instrument or another apparatus. They may be used in conjunction with a labo-
ratory work station or dedicated to a particular instrument, such as a gas or
liquid chromatograph, mass spectrometer or flow injection analyzer. Turntable
autosamplers have a fixed sampling device consisting of a hollow stainless steel
needle pipet that dips into each sample vial as it is rotated into position, the
liquid being drawn into the pipet under vacuum. More versatility is available
with xyz autosamplers because they automatically adjust the height of the pipet
(the z-direction) to take account of sample volume as well as being able to move
to any sample vial (x and y directions) following any predetermined sequence.

330 Section H – Sensors, automation and computing

Printer

Laboratory

information

system

Power and

event

control

Other

laboratory

apparatus

Sample

racks Cappingstation

Optional

hands with

parking

stations

Balance Sample

conditioning

‘Future’

Analytical

instrument

Centrifuge

Master

laboratory

station dispense,

dilute and extract

Zymate

Robot

Zymate

laboratory

controller

Fig. 2. A laboratory work station and cylindrical geometry robot arm. Reproduced with

permission from Zymark Co.