Nitrite Test Kits
Visual Kits
| Range | MDL | Method | Type | Test Kit | Refill |
|---|---|---|---|---|---|
| 0.0 - 0.1 & 0 - 1 ppm as N | 0.005 ppm | Azo Dye Formation (NED)  |
CHEMets | K-7006 | R-7006 |
| 0.0 - 2.5 ppm as N | 0.2 ppm | Azo Dye Formation | CHEMets | K-7004 | R-7002 |
| 0 - 250 ppm as N | 20 ppm | Azo Dye Formation | HR CHEMets |
K-7020B | R-7002 + A-0171 |
| 0 - 2,000 ppm as N | 160 ppm | Azo Dye Formation | HR CHEMets |
K-7020C | R-7002 + A-0171 |
| 250 - 2,500 ppm as NaNO2 | 250 ppm | Ceric Sulphate Titrant / Ferroin | Titrets | K-7025 | - |
| 500 - 5,000 ppm as NaNO2 | 500 ppm | Ceric Sulphate Titrant / Ferroin | Titrets | K-7050 | - |
Photometric Kit
| Range | Method | Type | Test Kit |
|---|---|---|---|
| 0 - 0.750 ppm as N | Azo Dye Formation (NED) |
Vacu-vials | K-7013 |
| 0 - 1.00 ppm as N | Azo Dye Formation | Vacu-vials | K-7003 |
CHEMetrics for the determination of Nitrite in aqueous solutions employs the well-known Azo Dye Formation and Ceric Sulphate titrimetric methods to deliver sensitivity and accuracy within minutes. Based on CHEMetrics patented Self-Filling Reagent Ampoule technology. Premixed. Premeasured. Precise. Visual and instrumental nitrite testing kit formats span low and high measurement ranges. CHEMets® and HR CHEMets® visual test kits use colour comparators for analysis. Titrets® offer a unique reverse titrimetric method. Vacu-vials® instrumental kits rely on CHEMetrics direct-readout photometers or spectrophotometers capable of accepting a 13-mm diameter round cell. Each kit contains 30 tests. Suitable for potable water, surface water, stormwater, groundwater, seawater and wastewater testing.
Azo Dye Formation Method
Nitrite diazotises with a primary aromatic amine in a chromotropic acid solution to produce a highly red coloured azo dye. The intensity of the colour is directly proportional to the concentration of nitrite in the sample. Recommended for higher nitrite concentrations. Nitrate will not interfere. Results are expressed as ppm (mg/l) NO2-N.
Use of the primary aromatic amine N-(1-naphthyl)ethylenediamine dihydrochloride (NED) with this method allows for lower range testing, improved sensitivity and reduced analysis time from 10 to 8 minutes. The NED method does not employ chromotropic acid. NED readily undergoes a diazonium coupling reaction in the presence of nitrite to give a strongly coloured pink azo compound, which allows for reliable and accurate lower range testing. The intensity of the colour is directly proportional to the concentration of nitrite in the sample. The NED method is widely used in the quantitative analysis of nitrite in water samples.
Reference:
APHA Standard Methods, 22nd ed., Method 4500-NO2¯ B- 2000. USEPA Methods for Chemical Analysis of Water and Wastes, Method 354.1 (1983).
|
Technical Data Sheet |
Ceric Sulphate Titrimetric Method
Ceric sulphate is the titrant and ferroin is the end point indicator. The method is free from glycol interference in samples that contain up to 75 % glycol, making it particularly applicable to systems that contain nitrite corrosion inhibitors. Results are expressed as ppm (mg/l) NaNO2.
Reference:
Developed by CHEMetrics, LLC
|
|
Technical Data Sheet |
Applications
The decomposition of organic matter producing nitrites occurs in wastewater treatment plants, water distribution systems and natural waters. Nitrites are useful as corrosion inhibitors, preservatives, pigments, and in manufacturing many organic preservative chemicals. Sodium nitrite is widely used in chemical and pharmaceutical industries. The Directive Prescribed Concentration or Value (PCV) for nitrite in the UK is 0.5 mg/l (ppm) in drinking water supplies and 0.1 mg/l at water treatment works. The Prescribed Concentration or Value (PCV) for Ireland in drinking water supplies is the same. The USEPA has established a Maximum Contaminant Level of 1 mg/l for nitrite-nitrogen in drinking water.
What is Nitrite?
Nitrite is an anion with the chemical formula NO2-. It is produced by the reaction of nitrogen oxides with either sodium hydroxide or sodium carbonate. Organic nitrites (alkyl nitrites) contain the -ONO group. Nitrite is an intermediate in the nitrogen cycle, is formed during the decomposition of organic matter but readily oxidises to form nitrate.