ORBECO SP600, Instruction Manual, Page: 35 / 334

33
SP600 Spectrophotometer 01/2008
1.1 Methods
Sample preparation: Reaction times must
be exactly kept !
1. Prepare the dry reaction apparatus (note 4) and place
it under a fume hood (toxic fumes!).
2. Pipette 50 ml of water sample into a 100 ml Erlen-
meyer flask (NS 29/32).
3.
30 ml Sulfuric Acid
,
2.0 ml Potassium Iodide solution and
0.3 ml Tin(II)chloride
are added to the water sample.
4. Close the flask and shake, wait for a period of 15
minutes .
5. Prepare
2.0 g Zinc
.
6. Fill the absorption tube with exact 5.0 ml of absorption
solution
(see picture and ; use pipette).
7. After end of the 15 minutes reaction time add the
2 g Zinc to the Erlenmeyer flask and immediately as-
semble the apparatus with the prepared absorption
tube (see picture
).
8. The reaction starts (fume hood!) .
Wait for 60 minutes reaction time.
Performing test procedure:
9. Fill a clean 20 mm cell (note 1) with deionized water .
10 Place the cell in the sample chamber making sure that
the positioning is correct.
11. Press ZERO key.
12. After zeroing remove the cell from the sample chamber.
Empty the cell and dry completely.
13. Fill the cell with the colored absorption solution. (see
picture ).
14. Place the cell in the sample chamber making sure that
the marks are aligned.
15. Press TEST key.
The result is shown in the display in mg/l Arsenic.
prepare Zero
press ZERO
Zero accepted
prepare Test
press TEST