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Procedure – LaMotte SMART Spectro Spectrophotometer User Manual

Page 197

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PROCEDURE

Use universal sample holder

1. Press and hold ON button until spectrophotometer turns on.
2. Scroll to and select PROGRAMMED TESTS.
3. Scroll to and select ALL TESTS (or another sequence containing

69 Nitrite-TT) from TESTING MENU.

4. Scroll to and select 69 Nitrite-TT from menu .
5. Rinse a tube (0290) with sample water. Fill to 10 mL with sample.
6. Insert the tube into chamber, close lid and select SCAN BLANK.
7. Remove the tube from Spectro.
8. Add one *Nitrite Spectrophotometric Grade Tablet (3886A).
9. Use Tablet Crusher (0175) to crush tablet.
10. Cap tube.
11. Shake vigorously for 20 seconds.
12. Wait 2 minutes.
13. Insert tube into chamber, close lid and select SCAN SAMPLE. Record result

in ppm nitrite.

14. Press OFF button to turn the spectrophotometer off or press EXIT button to

exit to a previous menu or make another menu selection.

NOTES: For best possible results, a reagent blank should be determined to

account for any contribution to the test result by the reagent system. To determine

the reagent blank, follow the above test procedure to scan a distilled or deionized

water blank. Then follow the above procedure to perform the test on a distilled or

deionized water sample. This test result is the reagent blank. Subtract the reagent

blank from all subsequent test results of unknown samples.

To convert nitrite (NO

2

) results to nitrite-nitrogen (NO

2

–N), divide results by 3.3.

NITRITE, TesTab

SMART Spectro Test Procedures 2.11

Test P

rocedures