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

• Type: Article in International Scientific Journal
• Date: 1997

Authors

Junior, LR (Author) Other; Neto, GD (Author) Other; Lima, JLFC (Author) FFUP; Montenegro, MCBSM (Author) FFUP; Silva, VL (Author) Other

Journal

Title: Analytical Sciences

Vol. 13

Pages: 589-594

ISSN: 0910-6340

Publisher: Japan Society for Analytical Chemistry

Indexing

ISI Web of Knowledge - 9 Citations

Scopus - 10 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6