Hach DR/700 - Page 255

50-5
CYANURIC ACID, continued
b) Make 2 cyanuric acid standards using the technique described in Step
5 of the procedure. Make one slightly less concentrated and the other
slightly more concentrated than the anticipated concentration of the
water sample.
c) Perform Steps 6-8 with both these standards.
d) With Filter Module 51.01 installed, perform paragraph 3.2.4.1,
Calibration Using Two Prepared Standards, in the DR/700 instrument
manual. Either standard can be used as Standard 1 or Standard 2.
Calibration must be completed within 7 minutes after the 3-minute
reaction period.
SUMMARY OF METHOD
The test for cyanuric acid uses the turbidimetric method. Cyanuric Acid
2 Reagent precipitates any cyanuric acid present and holds it in
suspension. The amount of turbidity caused by the suspended particles
is directly proportional to the amount of cyanuric acid present.
REQUIRED REAGENTS
Quantity
Description Per Test Unit Cat. No.
Cyanuric Acid 2 Reagent
Powder Pillow . . . . . . . . . . 1 pillow . . .50/pkg . . . . . . . . 2460-66
Cyanuric Acid . . . . . . . . . . . . . 1 g . . . . . . . . 25 g . . . . . . . . . . . 7129-24
Water, demineralized. . . . . . . . 1 L. . . . . . . . 4 L . . . . . . . . . . . . . 272-56
REQUIRED APPARATUS
Balance, analytical . . . . . . . . . 1 . . . . . . . . .each . . . . . . . . . . 22310-00
Clippers, for opening
powder pillows . . . . . . . . . 1 . . . . . . . . .each . . . . . . . . . . . 968-00
DR/700 Filter Module
Number 50.01. . . . . . . . . . . 1 . . . . . . . . . each . . . . . . . . . . 46250-00
Flask, volumetric, 1000 mL . . 3 . . . . . . . . .each . . . . . . . . . . 14574-53
Pipet, Filler, Safety Bulb . . . . . 1 . . . . . . . . . each . . . . . . . . . . 14651-00
Choose one or more based on calibration volume (Class A):
Pipet, volumetric,
Class A, 1.00 mL . . . . . . . . 1 . . . . . . . . .each . . . . . . . . . . 14515-35
Pipet, volumetric,
Class A, 2.00 mL . . . . . . . . 1 . . . . . . . . .each . . . . . . . . . . 14515-36