Hydroquinone procedure – LaMotte SMART Spectro Spectrophotometer User Manual

Page 208

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HYDROQUINONE 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

49 H-quinone) from TESTING MENU.

4. Scroll to and select 49 H-quinone 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 spectrophotometer.
8. Add 3 drops of *DEHA Reagent #1 (4791). Swirl to mix.
9. Add 3 drops of *DEHA Reagent #2 (4792). Swirl to mix.
10. Add 3 drops of *DEHA Reagent #3 (4793). Invert 3 times to mix.
11. Insert the tube into chamber. Close lid.
12. Wait 15 minutes. Do not open the lid during the waiting time. The reaction is

photosensitive.

13. Remove tube from chamber. Invert 2 times to mix.
14. Immediately insert tube into chamber, close lid and select SCAN SAMPLE.

Read within 30 seconds. Record result in ppm hydroquinone.

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

exit to a previous menu or make another menu selection.

NOTE: 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.

SMART Spectro Test Procedures 2.11

OXYGEN SCAVENGERS

Test P

rocedures

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