Thermo Scientific Orion AquaMate UV-Vis, Руководство пользователя

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Chapter 5
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Orion AQUAfast Reagent Chemistry Instructions for Orion AquaMate
90 | Orion AquaMate Spectrophotometer User Manual Thermo Scientific
AC2046 Nitrite Tablet Test
N-(1-Naphthyl)-ethylenediamine Method
0.01 – 0.5 mg/l N (Nitrite as Nitrogen)
1. Load and run the AC2046 method.
2. Fill a clean AQUAfast 24mm round vial, Cat. No. AC2V24, with 10 ml of sample. Close the
vial tightly with the cap. Wipe the exterior of the vial.
3. Place the vial into the holder in the sample chamber and close the chamber door.
4. Press the Measure Blank function key to measure the blank.
5. Open the sample chamber door and remove the vial from the holder.
6. Add one Nitrite LR Tablet straight from the foil into the vial. Crush the tablet with a clean
stir rod.
7. Close the vial tightly with the cap and swirl or invert several times until the tablet is
dissolved. Wipe the exterior of the vial.
8. Wait for a reaction period of 10 minutes.
9. Place the vial into the holder in the sample chamber and close the chamber door.
10. Press the Measure Sample function key to display the result in mg/l nitrite as N.
Notes:
• The following ions can produce interferences since under the reaction conditions they
cause precipitation: antimony (III), iron (III), lead, mercury (I), silver, chloroplatinate,
metavanadate and bismuth. Copper (II) ions may cause lower test results as they
accelerate the decomposition of the diazonium salt. It is unlikely in practice that these
interfering ions will occur in such high concentrations that they cause significant reading
errors.
• Conversion: mg/l NO
2
= mg/l N x 3.29