Highly versatile and automated total ammonia nitrogen compact analyzer suitable for different types of water samples

Abstract

Continuous monitoring of total ammonia nitrogen (TAN) currently needs to improve further not only to meet optimal analytical features but also to reduce equipment maintenance needs and avoid manual intervention. The development, evaluation in different aqueous samples (fresh and wastewater) and validation of a fully automated and adaptable miniaturized potentiometric analytical instrument with this purpose are presented. The main goals accomplished are a wider and adaptable working range (0.08 to 1000 mg L⁻¹ NH₄⁺) with a detection limit of 0.03 mg L⁻¹ and a significant reduction of reagent and sample consumption, as well as waste generation, compared to current commercial potentiometric flow analyzers. Moreover, different programmable calibration and sample analysis protocols have been successfully applied. Finally, suitable analytical features in terms of accuracy and precision are achieved even with samples with very complex matrices without any pretreatment required.