| 摘要 |
A method of determining one or more dissolved species in a fluid sample comprises transporting the sample through a flow channel which on a wall thereof has a sensing surface capable of binding the species to form an analyte depleted layer (6) extending from the surface, and determining the extent of binding of the species to the sensing surface. According to the invention, the sample contains suspended or emulsified material and is transported through the flow channel in a laminar flow such that there is formed a flow core (4) of the suspended or emulsified material and a surrounding liquid layer (5) near the flow channel wall, which layer is substantially free from suspended or emulsified material. The sample flow rate is controlled such that the thickness ( delta ) of the liquid layer (5) near the sensing surface is greater than the thickness (LD) of the analyte depleted layer (6), the binding of the species to the sensing surface thereby being at least substantially independent of the proportion of suspended or emulsified material in the sample. |
