A miniature and field-applicable multipumping flow analyzer for ammonium monitoring in seawater with fluorescence detection

作者：Horstkotte Burkhard; Duarte Carlos M; Cerda Victor^*

来源：Talanta, 2011, 85(1): 380-385.

DOI：10.1016/j.talanta.2011.03.078

• Multipumping flow analysis
• Ammonium
• Seawater
• Miniature reaction coil thermostat
• o-phthalaldehyde
• Fluorescence detection
• Photomultiplier
• Long-pass optical filter
• LED excitation

In this article, a simple, economic, and miniature flow analyzer for ammonium in seawater based on the solenoid micropumps is presented. A single reagent of sodium tetraborate, ortho-phthaldialdehyde (OPA), and sodium sulfite was used and optimized applying the modified SIMPLEX method. A special-made detection cell for fluorescence detection of the reaction product isoindol-1-sulfonat was made and combined with a commercial photomultiplier tube, a long-pass optical filter, and an UV-LED as excitation light source. A LOD down to 13 nmol/L was achieved. The fabrication and application of a miniature reaction coil heating device for reaction rate enhancement is further described. The system featured an injection frequency of 32 h(-1) at average standard deviation of 3%.

• 出版日期2011-7-15