Single-chip based contactless conductivity detection system for multi-channel separations

Abstract

In this work, the design and characterization of a multi-cell capacitively coupled contactless conductivity detection system are described. The operation and simultaneous acquisition from 3 detector cells are demonstrated, however, the system is capable of supplying 8 detection cells and can be easily upgraded to maintain 64 capacitively coupled contactless conductivity detection cells. On performing flow-injection analysis, the system recorded as low as 0.01 mM of acetic acid, phosphoric acid, NaH₂PO_4, and Na₂B₄O₇ solutions in water. The instrument was also capable of recording and distinguishing different mixtures of organic solvents: (a) methanol–acetonitrile, (b) hexane–acetone. The designed detection system is expected to be used coupled with multi-channel separation devices for monitoring simultaneous processes.