Enhancement of signal-to-noise ratio in chip-hased capillary electrophoresis systems by a Hadamard transform approach

The first demonstration of Hadamard transform capillary electrophoresis(CE) is reported for enhancing the signal-to-noise ratios(S/N) on a microfluidic chip using a simple electrokinetically gated injection approach in this paper. Sample or running buff er was alternatively injected into the separation channel according to a 7-bit, 127-step pseudorandom binary sequence(PRBS). The electrophoregram rebuilt from detector signal with inverse. Hadamard transform improved the SIN ratio by a factor of 5 (5. 6 in theory), compared to conventional single injection electrophoregram, almost without affecting the sample throughput.