Miniature flow-injection analysis manifold created by micromilling.
The miniature flow injection analysis (muFIA) system is based on a mechanically engraved manifold in a PMMA-substrate. The channels have a trapezoidal cross-section with a depth of 150 mum and a width between 180 and 360 mum and the reactor volume is 3.75 mul. A light-emitting diode (LED) is used as radiation source for absorbance detection and optical fibres are used for transmitting light to and from the manifold. Computer controlled valves are used for directing the liquid flows maintained with syringe pumps. A sampling rate of approximately five determinations per minute was achieved with a reagent consumption of 10 mul min(-1). Four applications were implemented and tested; the performance was found to be comparable to that obtained with conventional FIA-set-ups despite the drastically reduced optical pathlength. Electrokinetic pumping was extensively evaluated but found to generally be very restricted in scope because the reagent solutions cannot usually be adapted to the requirements for generating the flow.
Rainelli
Andrea
A
Department of Chemistry, The University of Basel, Spitalstrasse 51, 4004 Basel, Switzerland.
Stratz
Richard
R
Schweizer
Karin
K
Hauser
Peter C
PC