ORBECO SP600, Instruction Manual, Page: 232 / 334

230 SP600 Spectrophotometer 01/2008
1.1 Methods
Phosphate, acid hydrolyzable
with Tube Test
0.02 – 1.6 mg/l P
1. Open one white capped
digestion tube PO4-P Acid
reagent and add 5 ml of water sample .
2. Close the vial tightly with the cap. Invert the vial gently
several times to mix the contents.
3. Heat the vials for
30 minutes
in the preheated reactor
at a temperature of 100°C .
4. After 30 minutes remove the vial from the reactor.
(CAUTION: The vials are hot!)
Allow the vials to cool to room temperature.
5. Open the cooled digestion vial and add 2 ml 1.00 N
Sodium hydroxide solution
to the vial.
6. Close the vial with the cap and invert the vial gently
several times to mix the contents.
7. Place the vial in the sample chamber making sure that
the marks are aligned.
8. Press ZERO key.
9. Remove the vial from the sample chamber.
10. Add one VARIO Phosphate Rgt. F10 powder pack
straight from the foil to the vial (Note 2).
11. Close the vial tightly with the cap and swirl several
times to mix the contents (approx. 10-15 sec., Note 3).
12. Place the vial in the sample chamber making sure that
the marks are aligned.
13. Press TEST key.
Wait for a reaction period of 2 minutes .
After the reaction period is finished the measurement
starts automatically.
The result is shown in the display in mg/l acid hydroly-
zable Phosphate.
prepare Zero
press ZERO
Zero accepted
prepare Test
press TEST
Countdown
2:00
1 2
3 4
Ø 16 mm
3 2 5