ORBECO SP600, Instruction Manual, Page: 192 / 334

190 SP600 Spectrophotometer 01/2008
1.1 Methods
Nitrogen, total LR 2
with Tube Test
0.5 – 14 mg/l N
Digestion:
1. Fill one of the supplied digestion vials with 5 ml of the
water sample .
2. Add 1 level spoon of No. 8 (black) digestion rea-
gent.
3. Close the vial tightly with the cap and invert several
times to mix the contents.
4. Heat the vial for 60 minutes in a preheated thermo-
reactor at a temperature of 100°C .
5. Remove the vial from the thermoreactor.
(CAUTION: The vials are hot!).
Invert the vial and allow to cool to room temperature.
6. Add 1 level spoon of No. 4 (grey) compensation
reagent.
7. Close the vial tightly with the cap and invert several
times to mix the contents.
8. Use this pre-treated sample for the following test procedure:
Performing test procedure:
9. Place the supplied blank (red label) in the sample cham-
ber making sure that the marks are aligned.
10. Press ZERO key.
11. Remove the vial from the sample chamber.
12. Open one reagent tube and add 0.5 ml of the pre-
treated sample (step 8).
13. Close the vial tightly with the cap and invert several
times to mix the contents.
(Caution: Vial becomes warm!)
Ø 16 mm
prepare Zero
press ZERO
2 8 3