Micro-Analytical (μFIA) Reactor for the Determination of Phosphate as Orthophosphate

Sample preparation and measurement procedures that are currently performed in modern analytical laboratory facilities, can be scaled down to a device of a few sq.cm. 1,2. Such a device often employs electroosmotic flow (EOF) for solution mobilisation and sample injection, so avoiding backpressure problems and enabling electrophoretic separation to be carried out if required 3,4. Recently Daykin and Haswell3 described a μFIA system for the determination of orthophosphate based on EOF. This current work represents a follow up study of the operational characteristics of the Daykin μFIA system, focusing in particular, on the use EOF for the mobilisation of both the ascorbic acid and ammonium molybdate reagents together with on-chip sample injection and detection.