LaMotte SMART3 Colorimeter - Manual (Page 227)

PROCEDURE
Use COD/UDV adapter.
1. Preheat COD reactor to 100 ±2°C. Follow safety precautions.
2. Remove caps from two *Total Nitrogen Hydroxide Reagent Tubes (4040).
3. Use a 0.15 g spoon (0727) and a funnel (0459) to add one level measure of
*Digestion Reagent Powder (4036) to each tube. Tap funnel to dispense powder
completely.
4. Use a 1.0 mL pipet (0354) to add 2.0 mL of Deionized Water (5115PS), or
organic-free water, to one tube. This is the blank.
5. Use another 1.0 mL pipet (0354) to add 2.0 mL of sample to the other tube. This
is the sample.
6. Cap both tubes and shake vigorously for 30 seconds.
7. Place the tubes in the COD reactor for 30 minutes.
8. After exactly 30 minutes, turn the reactor off. Carefully remove the tubes from the
reactor and allow them to cool to room temperature.
9. At the end of the cooling period, press and hold ON button until colorimeter
turns on.
10. Press and hold until colorimeter turns on.
11. Press ENTER to select TESTING MENU.
12. Select ALL TESTS (or another sequence containing 069 Nitrogen Total) from
TESTING MENU.
13. Scroll to and select 069 Nitrogen Total from menu.
14. Carefully remove caps from the digested tubes.
15. Use a 0.15 g spoon (0727) and a funnel (0459) to add one level measure of
*Total Nitrogen Reagent A Powder (4041). Tap funnel to dispense powder
completely. Cap the tubes and shake for 15 seconds.
16. Wait 3 minutes.
17. Remove the caps from the tubes. Add one *Total Nitrogen Reagent B Tablet
(4042) to each tube. Cap the tubes and shake for 45 seconds or until the tablet
disintegrates.
18. Wait 2 minutes.
19. Remove the caps from the reacted tubes. Carefully remove the caps from two
*Total Nitrogen Acid Reagent Tubes (4043).
CAUTION: Tubes contain a strong acid.
20. Use another 1.0 mL pipet (0354) to add 2 mL of digested, treated blank to one
Total Nitrogen Acid Reagent Tube. This is the blank.
21. Use another 1.0 mL pipet (0354) to add 2 mL of digested, treated sample to the
SMART3 Test Procedures 2.11 NITROGEN, Total
Test P
rocedures