Sampling And Storage; Accuracy Check - Hach POCKET COLORIMETER II Instruction Manual

Phosphorus, Reactive,

Sampling and Storage

Collect sample in plastic or glass bottles that have been cleaned with 1:1
Hydrochloric Acid Solution and rinsed with deionized water. Do not use
commercial detergents containing phosphate for cleaning glassware used in
phosphate analysis.
Best results are obtained when samples are analyzed as soon as possible after
collection. If prompt analysis is impossible, preserve samples up to 48 hours by
storing at or below 4 °C. Warm to room temperature before testing.

Accuracy Check

Standard Additions Method
1. Measure exactly 25.0 mL of sample into each of three 50-mL beakers.
2. Using the Ampule Breaker Kit, snap the neck off a Phosphate Voluette
Ampule Standard Solution, 50 mg/L PO
3. Use a TenSette
respectively, to the three 25-mL aliquots of sample. Mix each thoroughly.
continued
®
Pipet to add 0.1 mL, 0.2 mL, and 0.3 mL of standard,
3– .
4
1—24
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