Alternative plugs flow liquid chromatography (APFLC)/EI-MS system using a T-shaped flow path.

The vapor condensation method can be used for forming an alternative flow of liquid masses using a single solvent for alternative plugs flow liquid chromatography (APFLC), described in our previous paper. APFLC is more effective when adopting a T-shaped flow path and aqueous-organic solvents with a liquid-to-gas volume ratio (bulk fraction; β) ranging between 0.0006 and 0.004 in an open tubular GC capillary column at below 70°C. High-density plugs flow by a T-shaped flow path leads to extremely high resolution. Alternative plugs flow is formed when the liquid contact angle to the solid phase is above 75°. An aqueous mixture of the usual HPLC solvent can be readily used for APFLC. An EI-mass spectrum is obtained that is comparable with that in the NIST library, except for the DMF mixture medium. Due to low-pressure loss properties in the column, the system does not require a high-pressure liquid pump. Solid hydrocarbon resin with a contact angle to water of between 75° and 79°, such as polystyrene and olefinic polymers, is anticipated to be applicable to APFLC and hydro-membrane gas chromatography (HMGC) by a consideration of their surface tensions.