Microfluidic chip-based flow injection system for gas diffusion separation with an evaporation pump drive

A microchip-based flow injection system integrating gas diffusion separation with liquid core waveguide (LCW) photometric detection is presented with an evaporation micropump as fluid drive. The system was applied to the determination of ammonium ions. A reproducibility of 6.7% RSD (n=5) was achieved using an 1 mM NH4+ standard. The limit of detection for NH4+ was 50 mu M (3 sigma). A sample throughput of 36 h(-1) was achieved with a sample consumption of 50 nL for each cycle.