US Patent 7169300 Fractionating apparatus

A tip portion of a probe has a triple tube structure in which a fused silica capillary on the innermost side, a capillary made of FEP outside the fused silica capillary, and a stainless pipe on the outermost side are disposed coaxially. An eluate from a liquid chromatograph flows through the innermost flow passage, a matrix solution flows through the flow passage between the fused silica capillary and the FEP capillary, and a rinsing solution or air flows through the flow passage between the FEP capillary and the pipe.