Pulse modulation - A novel approach to gradient-based flow injection techniques

Development of a novel system for generation of gradients in flow injection analysis by pulse modulation is described. These user-selectable gradients are created by computercontrolled mixing of two solutions with a total volume as low as 75 muI and can be delivered under incremental or continuous flow conditions. Applications such as automated, single-standard instrument calibration are expected to benefit from high-precision linear gradients (r(2) = 0.99989, n = 55). Gradient methods in biochemisty and immunology such as kinetic measurement of biomolecular interactions will benefit from the small volume of these gradients, especially for analytes with limited availability.