Development of a sequential injection gas diffusion system for the determination of ammonium in transitional and coastal waters

• Type: Article in International Scientific Journal
• Date: 2011

Authors

Segundo, RA (Author) Other; Ribeiro Mesquita, RBR (Author) Other; Oliveira Barbosa Ferreira, MTSOB (Author) Other; Carvalho Pinheiro Teixeira, CFCP (Author) Other; Adriano Bordalo (Author) ICBAS; Santos Silva Rangel, AOSS (Author) Other

Journal

Title: Analytical Methods

Vol. 3

Pages: 2049-2055

ISSN: 1759-9660

Publisher: Royal Society of Chemistry

Indexing

ISI Web of Knowledge - 5 Citations

Scopus - 6 Citations

Other information

Authenticus ID: P-002-N6C

DOI: 10.1039/c1ay05129f

Abstract (EN): This work describes the development of a sequential injection system for the ammonium determination in transitional and coastal waters with a wide salinity range. Estuarine waters are rather complex matrices as their characteristics change considerably along the salinity gradient, as well as the ammonium levels. The developed system effectively solves these issues by converting ammonium into ammonia and using a gas diffusion unit (GDU) for matrix removal. The ammonium determination in a wide quantification range (0.1-5.0 mg L (1)) was obtained with small changes in the protocol sequence and was applied, not only to estuarine samples, but also well water samples (low salinity) and coastal waters (higher salinity). Spectrophotometry was the chosen detection system to measure the absorbance change in the bromothymol blue acid base indicator caused by the diffusion of ammonia through the GDU. Additionally, the developed system used a green chemistry approach, as there was no indicator reagent consumption per determination, still maintaining a good precision (relative standard deviation lower than 2%) and a low detection limit, 27 mu g L(-1) (1.5 mu M).

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7