In some regions, nitrate in drinking water is a big problem. By fertilizing the agricultural soils with industrial fertilizers or manure, nitrate enters the groundwater.1
Especially in agricultural areas, drinking water prepared from groundwater can have an increased amount of nitrate. Nitrate itself is not toxic but it can be metabolized in the body to nitrite, which in turn forms cancerogenic nitrosamines. Especially for babies, nitrate can be very dangerous.1
Therefor limits have been introduced to ensure safe drinking water. The limit for nitrate set by the EU directive is 50 mg/L NO3-, while the U.S. EPA specifies 10 mg/L NO3-N.2,3
Check the nitrate content of your water with MQuant® test strips using your smartphone for fast, convenient, and precise results. Test the simplest way to determine nitrate in aqueous solutions. This low-priced and easy-to-use analytical detection system provides reliable quantification of water, food & beverage samples for customers from research, industry, environment and diagnostics.
The following application note describes the determination of nitrate concentrations in drinking water samples using the MQuant® nitrate test strips in combination with the MQuant® StripScan app.
Nitrate ions are reduced to nitrite ions by a reducing agent. In the presence of an acidic buffer, these nitrite ions react with an aromatic amine to form a diazonium salt, which in turn reacts with N-(1-naphthyl)-ethylene-diamine to form a red-violet azo dye.
Mineral water and drinking water
0–500 mg/L NO3-
MQuant® Nitrate Test, colorimetric with test strips (1.10020)
The sample can be analysed in its original form.
For analysis, follow this procedure:
The results were verified by performing a reference analysis with the Reflectoquant® Test (1.16995) and Spectroquant® Test (1.09713). The measurement with the Reflectoquant® Test and Spectroquant® Test were performed according to the corresponding package insert.
In addition, spiking experiments were performed. For this purpose, the samples were spiked with 25 mg/L NO3-. Afterwards, the recovery rate (RR) was calculated based on the recovered content.
The results are shown in the following table.
The MQuant® Nitrate test in combination with the MQuant® StripScan app is a quick and easy way to analyze the nitrate concentration in drinking and mineral water. The spiking experiments showed a good recovery rate: The values are comparable to those measured with the Reflectoquant® test and the photometric Spectroquant® test for nitrate.
As always (whenever trying a new method of analysis) it is recommended to do plausibility checks and to compare the results with a reference method.