New Analysers for Dissolved Nutrients in Water
Hill Labs processes tens of thousands of samples annually for dissolved nutrient testing. The analysis of dissolved reactive phosphorus and dissolved nitrogen species, including ammoniacal nitrogen, nitrite, and nitrate, forms a core laboratory workflow where the timely delivery of high‑quality results is essential. We recently transitioned to a new Flow Injection Analyser (FIA) platform for all dissolved nutrient testing, and we are excited to share more information on this.
Dissolved nutrients are key water quality indicators and understanding nutrient concentrations is essential for a wide range of environmental samples - from effluents and trade wastes through to New Zealand's pristine lakes and rivers.
Along with other laboratories in New Zealand, Hill Labs has used Lachat Flow Injection Analysis instruments for the analysis of dissolved nutrients for many years. Flow Injection Analysis is a high‑throughput, automated technique known for its sensitivity and reproducibility, with the Lachat FIA instruments proving to be reliable and highly effective instruments.
In 2021, Hill Labs was advised that the Lachat FIA’s were being discontinued. Knowing that finding the right replacement would be critical, we undertook a comprehensive evaluation of various options for dissolved nutrient analysis, ultimately selecting the FIAlab FIAlyzer‑FLEX as the preferred solution. Key factors influencing this decision included the FIAlab system’s sensitivity, which was capable of meeting all current detection limit requirements alongside its robustness, with straightforward maintenance and ease of part replacement.
In addition, the FIAlab platform enabled Hill Labs to adopt a new method for total ammoniacal nitrogen that delivers significant health and safety benefits. The new ammoniacal nitrogen method eliminates the use of liquefied phenol in the lab, while also providing environmental benefits through the generation of lower-toxicity waste.
Hill Labs gained accreditation for the FIAlab dissolved nutrients in water methods in early 2026, and from 1st May the new FIAlab FIA’s have been used for all dissolved nutrients in water analysis. This represented a successful transition to the new FIA platform, while maintaining the delivery of high‑quality dissolved nutrient results to New Zealand’s environmental sector.
If you would like any further information on Hill Labs’ dissolved nutrient methods or the testing service, please contact the Client Services Team at env.csm@hill-labs.co.nz
