1.1 Product Description
The EST Centurion W and WS Purge and Trap Autosamplers are designed to automate
the tedious sample handling procedures associated with purge and trap analysis for
volatile organic compounds (VOC's) under current EPA methods. The EST Centurion
can be used for water and soil (optional) matrices and is designed as a stand-alone unit
for retrofit to any manufactured purge and trap concentrator. Laboratories in today’s
market have enormous challenges to reduce cost and improve productivity. The EST
Centurion provides the flexibility to meet these needs.
The EST Centurion W and WS are a state-of-the art robotic, X-Y-Z axis autosampler
with a unique Windows XPe™operating platform. The Autosampler has 100 sample
positions, (90 soil), with 2 removable 50 position trays. A vial cooling option is available
which allows the vials to be cooled to below 10°C.
To process a water sample, the 40ml VOA vial is placed in the tray. The Centurion W or
WS robotic arm moves to the programmed vial location and the sample needle is lowered
into the sample vial to a calibrated depth. The sample vial is pressurized, transferring the
sample from the vial through an inert pathway filling a fixed volume sample loop. The
overflow is carried out to waste. The internal standard is injected into the sample stream
and the sample is transferred to the sparge vessel located on the concentrator.
The syringe option for the Centurion W or WS autosampler allows automated sample
dilutions. The dilution range is from 2x to 400x. The Centurion W or WS robotic arm
moves to the vial location as described previously. Next, an aliquot of sample is pulled
from the vial and diluted using the chosen dilution factor, the sample is then sent through
an inert sample pathway, injected with internal standard and transferred to the sparge
vessel on the concentrator. The syringe option also provides the capability to sample
volumes from 5mls to 25mls in 1ml increments.
To process a soil sample, the 40ml VOA vial is placed in the tray. The Centurion WS
robotic arm moves to the programmed vial location. Unlike the water vial which stays in
the sample tray, in the soil mode, the vial is transported to the soil cup. In the soil cup,
internal standard can be transferred into blank water through the fixed volume loop to the
sample. The sample can then be heated, stirred and purged to your specifications.
Finally, the analytes purged out of the sample are transferred to the concentrator through
a heated transfer line.
The Centurion W or WS autosampler will rinse the sample pathway with hot water for
cleaning in preparation of the next sample. The number of rinses and rinse time for the
sample needle and sample loop are programmable. The Centurion W or WS can have two
distinct modes of operation. They are the Single Concentrator and Dual Concentrator
(optional) modes. The single concentrator mode will allow the vial autosampler to run
with one purge and trap concentrator. The optional Dual concentrator mode will allow the
Centurion W or WS autosampler to process and deliver water and soil samples to two
purge and trap concentrators on an efficient alternating basis. The Dual Mode
