Test 'N Tube Reagent Set measures orthophosphate in drinking water, wastewater and seawater.
16 mm Test 'N Tube Cuvette test measures 0.06-5.00 mg/L PO₄ or 0.02-1.60 mg/L P in drinking water, wastewater and seawater. The product uses ascorbic acid method (8048). Article 2742545 may be used to perform analysis of 25-50 samples. The product can be evaluated using DR900 only.
Procedure for PO₄ evaluation
Firstly, start program 535 P React (PV TNT). Secondly, pipet 5.0 mL of sample to the Test 'N Tube Vial and mix the vial content. Thirdly, insert the vial in the instrument and select ZERO. Finally, pour the content of PhosVer 3 Phosphate Powder Pillow and measure testing results. The measurement wavelength for spectrophotometers is 880 nm (DR1900: 710 nm). The required wavelength for colorimeters is 610 nm.
Summary of method
Orthophosphate enters into reaction with molybdate in acid medium producing mixed phosphate/molybdate complex. Ascorbic acid reduces the complex, giving intense molybdenum blue color.
Sample preparation
It is recommended to analyze the sample as soon as possible for accurate testing results. If instant analysis is not possible, filter and store the collected sample at or below 6 °C (43 °F) for up to 48 hours.
| Brand | Hach |
| Parameter | Orthophosphate |
| Measuring range | 0.06-5.00 mg/L PO₄ |
| Measuring range (2): | 0.02-1.60 mg/L P |
| Instrument | DR900 |
| Method | Ascorbic Acid method |
| Standard method | 8048 |
| Digestion required | No |
| Number of tests | 25 - 50 tests |
