2459200 QAC Reagent Set, 0.2-5.0 mg/L CTAB

Article 2459200 measures quaternary ammonium compounds (QAC) 0.2-5.0 mg/L CTAB in cooling tower water, pool water and spa water. The product uses Direct Binary Complex method (8337). QAC Reagent Set can be used for 100 tests. The product is compatible with all Hach spectrophotometers or colorimeters except DR/800 and PC II.

QAC Reagent Set includes:

• QAC Reagent 1 Powder Pillows (p/n 2401066)
• QAC Reagent 2 Powder Pillows (p/n 2401268)

Before starting analysis:

• Collect the cooling tower water, pool water or spa water sample in glass bottles rinsed with sample.
• It is not recommended to use plastic containers to collect the sample.
• Adjust the pH to ~7 using 5 N sodium hydroxide solution before sample evaluation.

Procedure for CTAB evaluation

Run program 401 QAC. Add 25mL of deionized water in the mixing bottle to prepare the blank. Pour 25mL of the cooling tower water, pool or spa water sample in the another bottle to prepare the sample. Add QAC Reagent 1 Powder Pillow to each mixing bottle and swirl the content of each bottle. Pour QAC Reagent 2 Powder Pillow to each mixing bottle and mix to dissolve the reagent. Transfer 10 mL of the blank solution into a blank cell, insert in the instrument and press ZERO. Transfer 10 mL of the pretreated sample into a sample cell, install in the cell holder and push READ.

Summary of method

The indicator enters into reaction with quaternary ammonium compounds forming pale pink to vivid purple color that should be measured photometrically.

Sample preparation

Reduce the sample pH to less than 2 using concentrated sulfuric acid to conserve the sample for later analysis. Store the sample at or below 6 °C (43 °F) for up to 28 days.