LaMotte SMART Spectro Spectrophotometer - Manual (Page 115)

until pink color disappears.
7. Remove fl ask from heat. Cool sample under running water. This is the digested
sample.
8. Pour digested sample into clean graduated cylinder (0418). Dilute to the 50 mL
line with Deionized Water (5115).
9. Press and hold ON button until spectrophotometer turns on.
10. Scroll to and select PROGRAMMED TESTS from menu.
11. Scroll to and select ALL TESTS (or another sequence containing
22 Chromium) from TESTING MENU.
12. Scroll to and select 22 Chromium from menu.
13. Rinse a clean tube (0290) with sample water. Fill to
14. 10 mL line with sample water.
15. Insert tube into chamber, close lid and select SCAN BLANK.
16. Remove tube from Spectro. Use 0.1 g spoon (0699) to add one level measure
of *Chromium Reagent Powder (V-6276). Cap and shake for one minute. Wait
3 minutes.
17. During the waiting period, fold a piece of fi lter paper in half, then in half again
to form a cone. Push corners together to open end, and insert into funnel
(0459).
18. Filter sample into a clean tube (0290). Cap and mix. Insert tube of fi ltered
sample into chamber, close lid and select SCAN SAMPLE. Record result.
19. Press OFF button to turn spectrophotometer off or press EXIT button to exit to
a previous menu or make another menu selection.
TRIVALENT CHROMIUM PROCEDURE
Subtract hexavalent chromium from total chromium. Record as ppm trivalent
chromium.
Trivalent Chromium = Total Chromium – Hexavalent Chromium
CHROMIUM-Hexavalent, Trivalent & Total SMART Spectro Test Procedures 2.11
Test P
rocedures