Femto liquid chromatography with attoliter sample separation in the extended nanospace channel

A liquid chromatography system, comprising a separation column with a width and depth of a few hundred nanometers, was fabricated on a glass microchip (femto liquid chromatography, fLC). The size of this system was approximately 10¹¹ times smaller than that of a conventional LC system, the flow rate was subpicoliter/ minute, and the injection volume was a few hundred attoliters. The fLC system did not require packing stationary phase and was capable of separating solutes with different molecular charges (fluorescein and sulforhodamine B) that could not be separated on a conventional LC column whose surface was covered with the same functional group as that of the column of the fLC system. The fLC system represented herein overcomes limitations of conventional chromatography separation, namely, heterogeneity of the stationary phases and eddy diffusion. Scale-down of the chromatography system brought advantages not only in reduction of sample volume but also in separation efficiency. The fLC system can analyze a very small amount of sample with high efficiency and will be useful in analyzing small samples, such as single cells and synaptic clefts. fLC greatly influences and benefits various fields such as life sciences, medicine, environmental science, and manufacturing by the improvement of separation technology.