Potentiometric FIA system with reactor based on natural urease source and tubular detector of ammonium ions. Determination of urea in fertilizers

• Tipo: Artigo em Revista Científica Internacional
• Data: 1997

Autores

Junior, LR (Autor) Outra; Neto, GD (Autor) Outra; Lima, JLFC (Autor) FFUP; Montenegro, MCBSM (Autor) FFUP; Silva, VL (Autor) Outra

Revista

Título: Analytical Sciences

Vol. 13

Páginas: 589-594

ISSN: 0910-6340

Editora: Japan Society for Analytical Chemistry

Indexação

ISI Web of Knowledge - 9 Citações

Scopus - 10 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

Outras Informações

ID Authenticus: P-001-AXC

DOI: 10.2116/analsci.13.589

Abstract (EN): An FIA system was developed to analyze urea by monitoring ammonium ions generated by enzymatic degradation with a tubular ion-selective electrode containing nonactin on polyvinyl chloride (PVC) membrane. As an urease source, 120 mg of the leguminous canavalia brasiliensis were immobilized in an enzymatic reactor with glutaraldehyde. Ammonium ions are converted to ammonia by an alkaline solution, 1 mol l(-1) NaOH, and permeates through a polytetrafluoroethylene membrane until the detector. The method can be used in an urea concentration range of 2.5X10(-4) to 2.5X10(-3) mol l(-1) (25.0 degrees C). Analysis of 25 mu l commercial samples of fertilizers, showed a relative error of 0.2% with a high selectivity to the species present.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 6