LaMotte SMART Spectro Spectrophotometer - Manual (Page 235)

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.
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. It is necessary to
determine the reagent blank only when a new lot number of reagents is obtained.
For the most accurate results, the sample and reagents should be at 25±4°C.
POTASSIUM SMART Spectro Test Procedures 2.11
Test P
rocedures