caa a22 4500 465745857 CHVBK 20180323111820.0 cr unu---uuuuu 170327e19900101xx s 000 0 eng 10.1007/BF00323120 doi (NATIONALLICENCE)springer-10.1007/BF00323120 Simultaneous-fluorimetric methods for the determination of ammonia and urea by use of flow injection configurations with dual injection valves [Elektronische Daten] [Andrés Izquierdo, Pilar Linares, M. Luque de Castro, Miguel Valcarcel] Summary: Two fluorimetric methods are proposed for the simultaneous determination of ammonia and urea based on the reaction of the former with o-phthalaldehyde/2-mercaptoethanol and on the use of a dual injection system in which the valves are coupled in series or in parallel. An enzymatic reactor converts urea into ammonia which is determined by the same reaction. These configurations provide very similar results with a linear determination range between 0.5 and 10.0 μg ml−1 and a sampling frequency of 60 h−1. The proposed methods are very tolerant to foreign species commonly found in water, as shown by applying them to samples of different origins. Springer-Verlag, 1990 Izquierdo Andrés Department of Analytical Chemistry, Faculty of Sciences, University of Córdoba, Cordoba, Spain aut Linares Pilar Department of Analytical Chemistry, Faculty of Sciences, University of Córdoba, Cordoba, Spain aut Luque de Castro M. Department of Analytical Chemistry, Faculty of Sciences, University of Córdoba, Cordoba, Spain aut Valcarcel Miguel Department of Analytical Chemistry, Faculty of Sciences, University of Córdoba, Cordoba, Spain aut Fresenius' Journal of Analytical Chemistry Springer-Verlag 336/6(1990-01-01), 490-493 0937-0633 336:6<490 1990 336 216 https://doi.org/10.1007/BF00323120 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00323120 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Izquierdo Andrés Department of Analytical Chemistry, Faculty of Sciences, University of Córdoba, Cordoba, Spain aut NATIONALLICENCE 700 1- Linares Pilar Department of Analytical Chemistry, Faculty of Sciences, University of Córdoba, Cordoba, Spain aut NATIONALLICENCE 700 1- Luque de Castro M. Department of Analytical Chemistry, Faculty of Sciences, University of Córdoba, Cordoba, Spain aut NATIONALLICENCE 700 1- Valcarcel Miguel Department of Analytical Chemistry, Faculty of Sciences, University of Córdoba, Cordoba, Spain aut NATIONALLICENCE 773 0- Fresenius' Journal of Analytical Chemistry Springer-Verlag 336/6(1990-01-01), 490-493 0937-0633 336:6<490 1990 336 216 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer