Accuracy Check (Free Ammonia Test) - Hach POCKET COLORIMETER II Instruction Manual

Nitrogen, Free Ammonia and Chloramine (Mono),

Accuracy Check (Free Ammonia Test)

Dilution water is required when testing a diluted sample and preparing standard
solutions. Dilution water must be free of ammonia, chlorine and chlorine demand.
A convenient source is a recirculating, deionizer system with carbon filtration
which produces 18 megaohm-cm water.
Standard Additions Method
1. Measure 50 mL of sample into three 50-mL mixing cylinders.
2. Use the TenSette Pipet to add 0.3, 0.6, and 1.0 mL of Ammonium Nitrogen
Standard, 10 mg/L as NH
3. Analyze each spiked sample, following all steps of the Free
Ammonia/Monochloramine procedure. The ammonia nitrogen concentration
should increase 0.02 mg/L for each 0.1 mL of standard added.
Standard Solution Method
Prepare a 0.20 mg/L ammonia nitrogen standard by diluting 2.00 mL of the
Ammonia Nitrogen Standard Solution, 10 mg/L, to 100 mL with dilution water.
—Or—
Use a TenSette Pipet to prepare a 0.20 mg/L ammonia nitrogen standard by
-N to the three samples. Mix well.
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