title: Analysis of river water samples utilising a prototype industrial sensing system for phosphorus based on micro-system technology.
abstract: The application of a phosphorus monitoring device based on microsystems technology (MST) to the analysis of river water is presented. An alternative to the standard molybdenum blue method known as the yellow vanadomolybdophosphoric acid method has been very effectively implemented. The method is simple, a reagent and sample are mixed in a 1:1 ratio forming a yellow complex that absorbs strongly below 400 nm in the UV spectrum. The kinetics of the reaction are rapid and sample turnaround is typically 3 min at room temperature. Therefore a very uncomplicated microfluidic design can be adopted. The working wavelength was chosen as 380 nm to coincide with the peak output of a UV-LED narrow bandwidth light source recently developed by Nichia. The limit of detection for the yellow method in the microfluidic system is 0.2 ppm with a dynamic linear range from 0-50 ppm. The method was applied to a measurement of phosphorus in a local river at specific sampling points along its course.
authors.affiliation: National Centre for Sensor Research, School of Chemical Sciences, Dublin City University, Dublin, Ireland.
authors.forename: Michaela
authors.initials: M
authors.lastname: Bowden
authors.forename: Margaret
authors.initials: M
authors.lastname: Sequiera
authors.forename: Jens Peter
authors.initials: JP
authors.lastname: Krog
authors.forename: Peter
authors.initials: P
authors.lastname: Gravesen
authors.forename: Dermot
authors.initials: D
authors.lastname: Diamond
mesh_terms: D000042:Absorption; D003124:Colorimetry / Q000379:methods; D004581:Electronics; D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods; D007700:Kinetics; D010758:Phosphorus / Q000032:analysis*; D014873:Water Pollutants / Q000032:analysis*
chemical_list: D014873:Water Pollutants; D010758:Phosphorus