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4.2.2 BioTector Sample Injection
The BioTector analyzes a precise volume of liquid. The Sample Pump injects a pre-programmed number of
pulses (half revolutions of pump) of liquid into the reactor for each measurement and therefore the volume of
liquid included in each pulse is consistent irrespective of sample source pressure.
Sample is initially drawn from the source by a peristaltic Sample Pump.
In standard TIC & TOC systems, Manual/Calibration Valve is activated to isolate any stream pressure or
vacuum coming from the sample lines. Sample Pump rotates forward for 4 pulses by default to remove any
pressure/vacuum within the pump tube. Sample Valve rotates 90 degrees clockwise and Sample Pump
rotates forward and injects the sample directly into the reactor with the relevant number of pulses appropriate
to the range. Sample Valve rotates a further 90° clockwise and the sample volume remaining within the
Sample Valve is washed into the BioTector reaction chamber (reactor) by the first TIC acid injection.
In TC systems, the sample injection is carried out similar to the one described for TIC & TOC systems above
but the sample volume remaining within the Sample Valve is washed into the reactor by a small quantity of
acid reagent.
In VOC systems, BioTector carries out two separate sample injections for the two analysis reactions run
consecutively in a single reactor configuration. The first analysis reaction is a TC reaction and the second one
is a TIC & TOC reaction. The sample injection takes place as described for the TC systems and for the TIC &
TOC systems above. Figure 4 shows the typical analysis layout of TIC & TOC, TC and VOC systems below.
Detailed information on sample injection is available, in presentation format, in the MMC/SD card shipped with
the BioTector. It is recommended to review this file to understand BioTector sample injection.
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