GE MOA 280i, Руководство по эксплуатации и обслуживанию

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GE Analytical Instruments ©2006
12-9
DLM 14291 Rev. A
injections and depending on the nitrite contamination in the water may not be
detectable. If the water is contaminated, large peaks will continue to be
observed; another source of water should be used.
Injection Technique
For best results, develop a standard procedure for the injections. One approach
that works well is:
•
Rinse the syringe once or twice with the sample and then pump the syringe
several times in the sample to remove any air bubbles.
•
Draw the plunger up to the desired volume, remove the needle from the
sample and then draw the plunger back to pull the sample into the barrel of
the syringe.
•
Use a Kimwipe® or paper towel to wipe the outside of the needle.
•
To insert the syringe into the purge vessel, it helps use to one hand to help
guide the needle through the septum on the purge vessel.
•
Push the syringe all the way down until the barrel rests on the top of the screw
cap. The end of the needle should be in the liquid reducing agent.
•
Rapidly depress the plunger to transfer the liquid into the purge vessel.
•
Withdraw the syringe, wipe the needle to remove any reducing agent and then
rinse the syringe two or more times with deionized water.
•
While the peak is returning to baseline, load the next sample into the syringe.
Preparation of Calibration Curve
After obtaining a clean water blank, inject the standards to prepare a calibration
curve. It is best to start with the most dilute standard and make duplicate
injections for each standard.
Linear Range and Off-scale Peaks
If the NOA output signal reaches 1000 mV, the linear range for the High Sensitivity
setting of the amplifier has been exceeded and the top of the peak has been “cut-