Chapter 5
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Orion AQUAfast Reagent Chemistry Instructions for Orion AquaMate
Thermo Scientific
Orion AquaMate Spectrophotometer User Manual
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93
19.
Press the Measure Blank function key to measure the blank.
20.
Open the sample chamber door. Remove the blank vial from the holder.
21.
Place the sample vial into the holder in the sample chamber and close the chamber door.
22.
Press the Measure Sample function key to display the result in mg/l nitrogen.
Notes:
•
Appropriate safety precautions and a good lab technique should be used during the whole
procedure.
•
Volumes for samples and blank should always be measured using 2 ml volumetric pipettes
(class A).
•
One blank is sufficient for each set of samples. After taking the blank measurement, it is
possible to measure several samples.
•
It is very important to remove the vials from the reactor after exactly 30 minutes.
•
Large quantities of nitrogen free, organic compounds that are included in some water
samples may reduce the effectiveness of the digestion by reacting with the persulfate
reagent. Samples that are well known to contain large quantities of organic compounds
must be diluted and digestion and measurement must be repeated for checking the
effectiveness of the digestion.
•
Application: for water, wastewater and seawater.
•
Interfering substances that resulted in a concentration change of 10%: Bromide more than
60 mg/l and chloride more than 1000 mg/l produce positive interferences.