A gas chromatographic (GC) column using a zwitterionic compound and methods of use thereof are disclosed herein. The volatile free acids were observed to strongly retain on these zwitterionic compounds-based columns with excellent peak symmetry. By carefully tuning the structures of these zwitterionic compounds, different selectivity toward volatile free acids was demonstrated. These stationary phases possess a wide working range with thermal stabilities at higher temperatures.

The present disclosure discusses a method of separating a sample (e.g., small organic acid metabolite) including coating a flow path of a chromatographic system. The coating along the flow path is vapor deposited and prevents or severely decreases metal interactions between the metallic chromatographic system and the sample.

Chromatography apparatus and methods are described, especially for expanded bed adsorption. A column tube has a process fluid input device at the bottom and a movable piston in the top. The piston is enclosed in the column by a cover plate. The piston body has an inflatable seal, and is connected by a frame to a contact ring which carries another inflatable member to contact the tube wall. Process fluid leaves the operating volume through an opening of the piston and flexible hose, through the enclosed space and out through the cover plate. The space above the piston can be pressurised to control piston movement. The contact ring maintains piston alignment. The inflatable seals are used to fix the piston in position, allow it to slide or allow washing. The piston outlet may include a vortex-inhibitor. Bed and piston levels may be monitored by ultrasound sensors.

A column packing material for supercritical fluid chromatography which allows good peak shape to be obtained in the analysis of free fatty acids, etc. and in the analysis of agricultural chemicals, etc., and has excellent durability for repeated analysis. The column packing material for supercritical fluid chromatography includes polymer particles containing cross-linked polymer, the degree of swelling of which after absorbing tetrahydrofuran and the degree of swelling of which after absorbing methanol are both 1.4 or less.

A column packing material for supercritical fluid chromatography which allows good peak shape to be obtained in the analysis of free fatty acids, etc. and in the analysis of agricultural chemicals, etc., and has excellent durability for repeated analysis. The column packing material for supercritical fluid chromatography includes polymer particles containing cross-linked polymer, the degree of swelling of which after absorbing tetrahydrofuran and the degree of swelling of which after absorbing methanol are both 1.4 or less.

The present disclosure is directed to a coating process for chromatographic surfaces. Embodiments of the present disclosure feature a two-step, vapor-liquid phase organosilane deposition method for creating a hydrophilic, non-ionic surface in a chromatographic system.

Provided is a guard column including a filling part having a length of 2.0 cm to 3.5 cm formed of a filler, in which the filler is made of porous silica gel having a hydrophilized surface and an average particle size of 1.5 μm to 2.5 μm, and a pressure difference when an aqueous solution is fed at a linear flow rate of 2.1 cm/min is 4.0 MPa or more.

Provided is a guard column including a filling part having a length of 2.0 cm to 3.5 cm formed of a filler, in which the filler is made of porous silica gel having a hydrophilized surface and an average particle size of 1.5 μm to 2.5 μm, and a pressure difference when an aqueous solution is fed at a linear flow rate of 2.1 cm/min is 4.0 MPa or more.

A method of operating a chromatography column is described. This method involves collecting column outlet signal and accumulated flow parameters at two or more intervals of at least one mobile phase transition front during operation of the chromatography column comprising column packing. A model gamma cumulative distribution curve is calculated based on the collected column outlet signal and accumulated flow parameters for the at least one mobile phase transition front. A height equivalent theoretical plate (HETP) value is calculated for the at least one mobile phase transition front using parameters of the model gamma cumulative distribution curve and the quality of the chromatography column packing is assessed based on the calculated HETP value.

A method of operating a chromatography column is described. This method involves collecting column outlet signal and accumulated flow parameters at two or more intervals of at least one mobile phase transition front during operation of the chromatography column comprising column packing. A model gamma cumulative distribution curve is calculated based on the collected column outlet signal and accumulated flow parameters for the at least one mobile phase transition front. A height equivalent theoretical plate (HETP) value is calculated for the at least one mobile phase transition front using parameters of the model gamma cumulative distribution curve and the quality of the chromatography column packing is assessed based on the calculated HETP value.