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Nutrients analysis

Our nutrient analysis services enable your process control and assessment of potential impacts of algae in your water.

Nitrogen and phosphorous are essential nutrients for the growth of plants – including algae.

However, an excess of N and P can stimulate nuisance growths of aquatic plants in water bodies and so measurement of N and P indicate how eutrophied (nutrient polluted) a water body is and how susceptible it will be to the growth of 'nuisance' plant life.


The forms of Nitrogen commonly analysed are Nitrate, Nitrite, Ammonia and Organic Nitrogen. Some sources of Nitrogen enrichment may include fertilisers (rural and urban areas), animal wastes (farms and feed lots) and sewage.

The most common forms of N available for plant growth in water are the inorganic forms namely nitrate, nitrite and ammonia and organic forms such as urea (the breakdown product of proteins). Nitrate is most commonly available and ammonia the most readily assimilated by plants. Total Kjeldahl Nitrogen (TKN) is another commonly requested analysis and includes ammonia and organic forms of nitrogen but not the oxidized forms.


The forms of Phosphorous commonly analysed are Filterable Reactive Phosphorus (FRP) and Total Phosphorous. Sources of Phosphorus enrichment may include some detergents, fertilisers (rural and urban areas), animal faeces (farms and feed lots), sewage and some industrial wastes.

Phosphorus exists in water as both dissolved and particulate forms. Particulate P includes P bound up in organic compounds such as proteins and P adsorbed to suspended particulate matter such as clays and detritus (dead and decaying organisms). Dissolved P includes inorganic orthophosphate (H2PO4-, HPO4-2 and PO4-3), poly phosphates, organic colloids and low molecular weight phosphate esters. Our most commonly measures filterable reactive phosphorus (FRP) as the best approximation of Available P, Total P, Organic P and Total Dissolved P can also be quantified.


Determining the various forms of Nitrogen and Phosphorous present in water assists you in process control and can be used to assess the potential impacts of algae in your water. Algae can cause undesirable tastes and odours in water.

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Our discrete analysers and flow injection analysers (FIA) are capable of faster processing times and lower limits of reporting compared to the older segmented flow analysers also known as auto-analysers. The current Limits of Reporting (LOR) are described below.

DeterminandLOR  (mg/L)
Ammonia as N0.005
Nitrate as N0.003
Nitrite as N0.003
Nitrite and Nitrate as N (OxN)0.003
Total  Kjeldahl Nitrogen as  N0.05
Total  Nitrogen0.05
   Filterable  reactive 0.003
   Total 0.005

Sample container
250ml plastic (PT250)

PT250 - none - none - no air gap, ice

Analytes & holding times
All water types
*Chloride (28 days)
*Fluoride (28 days)
*OXN/Nitrite (24 hours)
*Ammonia (6 hours)
*Filterable P (24 hours)

Sampling requirements
No air gap

Storage and preservation
Iced or chilled to 4°C.
No preservative.

Nutrients are analysed using discrete analysers, automatic flow analysers and a flow injection analyser (FIA).