Nitrate levels in water

Nitrate (NO₃⁻) levels in water are essential for assessing the quality of drinking water, surface water, and industrial effluents . Nitrates are nitrogen compounds resulting from the decomposition of organic matter , agricultural fertilizers , and industrial discharges .

In excess, they can have harmful effects on human health (risk of methemoglobinemia in infants) and on the environment (eutrophication of aquatic environments).
The objective of this analysis is therefore to quantify the nitrate concentration in order to:

• Check compliance with drinking water and discharge standards (European Directive 98/83/EC, Public Health Code).
• Monitor nitrogen pollution in agricultural and industrial areas.
• Evaluate the treatment performance in wastewater treatment plants or filtration systems.

Analytical methods used

Two main techniques are used for measuring nitrate levels in water:

• UV spectrophotometry : measurement of the absorbance of nitrate at a specific wavelength (approximately 220 nm). This rapid method allows for direct quantification of the concentration in clear or lightly charged samples.
• Ion chromatography (or ion exchange) : selective separation of anions (nitrates, nitrites, chlorides, sulfates) using an ion exchange column, followed by conductimetric detection. This technique offers high sensitivity and allows for the simultaneous analysis of multiple ions.

These analyses are carried out in accordance with international standards (ISO 7890-1 to 7890-3, NF EN ISO 10304-1), guaranteeing the traceability and reliability of the results .

Matrices involved

Nitrate levels can be measured on a wide variety of aqueous samples:

• Drinking and distribution water , to guarantee the health safety of consumers.
• Groundwater and surface water (rivers, lakes, groundwater) for environmental monitoring.
• Wastewater and industrial water , in order to control discharges from production sites.
• Agricultural effluents , to measure the impact of nitrogen fertilizers.

This analysis is suitable for environmental laboratories, water network operators, local authorities, agri-food industries and environmental consulting firms.

Industrial and regulatory applications

Controlling nitrate levels in water is a major requirement in many sectors:

• Environment and agriculture : assessment of nitrogen contamination and prevention of eutrophication of aquatic environments.
• Food processing industry : monitoring of water used in production and cleaning processes.
• Water treatment : validation of the performance of filters, ion exchange resins and biological processes.
• Public health : regulatory compliance for drinking water (maximum permitted value: 50 mg/L).

Compliance with these standards guarantees the protection of consumers and aquatic ecosystems , while preventing penalties related to regulatory breaches.

Interpretation of the results

The results are expressed in mg/L of NO₃⁻ .

• A concentration below 50 mg/L indicates compliance for drinking water.
• Higher values ​​may indicate pollution of agricultural or industrial origin requiring corrective measures.

Additional analyses of pH , conductivity and total organic matter (TOC) can help to better interpret the results and identify the source of contamination.

YesWeLab's expertise

YesWeLab provides a network of partner laboratories accredited to ISO 17025 and COFRAC , specializing in environmental and physico-chemical analyses of water .

Thanks to the YesWeLab digital platform , water analysis management is simplified: request for quotes, sample tracking and online consultation of test reports.

For comprehensive water quality monitoring, also check out:

• Ammonium dosage .
• Nitrite dosage .
• Total phosphorus dosage .

For any specific request, contact our scientific team so that we can design an analysis protocol tailored to your environmental needs.