A high performance microfluidic analyser for phosphate measurements in marine waters using the vanadomolybdate method

Talanta. 2013 Nov 15;116:382-7. doi: 10.1016/j.talanta.2013.05.004. Epub 2013 May 9.


We report a high performance autonomous analytical system based on the vanadomolybdate method for the determination of soluble reactive phosphorus in seawater. The system combines a microfluidic chip manufactured from tinted poly (methyl methacrylate) (PMMA), a custom made syringe pump, embedded control electronics and on-board calibration standards. This "lab-on-a-chip" analytical system was successfully deployed and cross-compared with reference analytical methods in coastal (south west England) and open ocean waters (tropical North Atlantic). The results of the miniaturized system compared well with a reference bench-operated phosphate auto-analyser and showed no significant differences in the analytical results (student's t-test at 95% confidence level). The optical technology used, comprising of tinted PMMA and polished fluidic channels, has allowed an improvement of two orders of magnitude of the limit of detection (52 nM) compared to currently available portable systems based on this method. The system has a wide linear dynamic range 0.1-60 μM, and a good precision (13.6% at 0.4 μM, n=4). The analytical results were corrected for silicate interferences at 0.7 μM, and the measurement frequency was configurable with a sampling throughput of up to 20 samples per hour. This portable micro-analytical system has a low reagent requirement (340 μL per sample) and power consumption (756 J per sample), and has allowed accurate high resolution measurements of soluble reactive phosphorus in seawater.

Keywords: Microfluidic analyser; Nutrient analysis; Phosphate measurement; Seawater; Silicate interference; Vanadomolybdate method.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Atlantic Ocean
  • Calibration
  • Hydrogen-Ion Concentration
  • Limit of Detection
  • Microfluidic Analytical Techniques / instrumentation*
  • Microfluidic Analytical Techniques / standards
  • Molybdenum / chemistry*
  • Phosphates / analysis*
  • Phosphoric Acids / chemistry*
  • Phosphorus / analysis*
  • Polymethyl Methacrylate / chemistry
  • Seawater / chemistry*
  • Silicates / chemistry
  • Vanadates / chemistry*


  • Phosphates
  • Phosphoric Acids
  • Silicates
  • Phosphorus
  • Vanadates
  • Molybdenum
  • Polymethyl Methacrylate
  • phosphomolybdic acid