LaMotte SMART Spectro Spectrophotometer - Manual (Page 213)

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
81 Potassium
) from TESTING MENU.
4. Scroll to and select 81 Potassium from menu.
5. Rinse a clean tube (0290) with sample water. Fill to the 10 mL line with
sample.
6. Insert tube into chamber, close lid and select SCAN BLANK.
7. Remove tube from Spectro. Add 4 drops of *Sodium Hydroxide, 1.0N
(4004WT). Cap and mix.
8. Use the 0.05 g spoon (0696) to add one measure of *Tetraphenylboron
Powder (6364). Cap and shake vigorously until all of the powder has
dissolved. Wait 5 minutes.
9. At end of 5 minute waiting period, mix tube again to suspend any settled
precipitate. Immediately insert tube into chamber, close lid and select
SCAN SAMPLE
. Record result.
10. Press
OFF button to turn spectrophotometer off or press EXIT button to
exit to a previous menu or make another menu selection.
þNOTES: 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. It is necessary to determine the reagent blank only
when a new lot number of reagents are obtained.
For the most accurate results, the sample and reagents should be at 25±4°C.
Potassium 2/2 SMART SPECTRO TEST PROCEDURES 05.04