A method for quantifying Hex4, lyso-GM1, Fuc-GlcNAc-Asn, or lyso-sulfatide included in cerebrospinal fluid, the method including adding an internal standard substance to a solution including the cerebrospinal fluid, submitting the solution including the cerebrospinal fluid, to which the internal standard substance has been added, to liquid chromatography to obtain an eluate, and subjecting the eluate to mass analysis.

In an ion chromatograph, a sample that is included in an eluent and is to be measured is separated into ion species components by a separation column. An electrode liquid to be introduced into an input port is branched by a three-way valve and is discharged from each of a first output port and a second output port. An eluent from the separation column passes through an eluent flow path of an ion suppressor. An electrode liquid from the first and second output ports passes through each of an anode-side flow path and a cathode-side flow path of the ion suppressor. Ion exchange is performed by electrolysis between an eluent that passes through the eluent flow path and an electrode liquid that passes through the anode-side flow path and the cathode-side flow path, and a sample that passes through the eluent flow path and is separated by the separation column is detected by a detector. A backward flow of an electrode liquid in the cathode-side flow path is suppressed by a backward flow suppression mechanism.

In an ion chromatograph, a sample that is included in an eluent and is to be measured is separated into ion species components by a separation column. An electrode liquid to be introduced into an input port is branched by a three-way valve and is discharged from each of a first output port and a second output port. An eluent from the separation column passes through an eluent flow path of an ion suppressor. An electrode liquid from the first and second output ports passes through each of an anode-side flow path and a cathode-side flow path of the ion suppressor. Ion exchange is performed by electrolysis between an eluent that passes through the eluent flow path and an electrode liquid that passes through the anode-side flow path and the cathode-side flow path, and a sample that passes through the eluent flow path and is separated by the separation column is detected by a detector. A backward flow of an electrode liquid in the cathode-side flow path is suppressed by a backward flow suppression mechanism.

First and second flow-path portions are opposite to each other, and communicate with each other such that a direction in which an eluent flows through the first flow-path portion and a direction in which an eluent flows through the second flow-path portion are opposite to each other. First and second electrode liquid flow paths are respectively opposite to the first and second flow-path portions. First and second electrode liquids are respectively supplied to the first and second electrode liquid flow paths, such that a direction in which the first electrode liquid flows through the first electrode liquid flow path is same as a direction in which an eluent flows through the first flow-path portion and a direction in which the second electrode liquid flows through the second electrode liquid flow path is same as a direction in which an eluent flows through the second flow-path portion.

A method, device, and system for removing a volatile component from a liquid solution for a chromatographic separation are described. The method includes the flowing of a liquid solution through a first chamber of the device. A volatile component in the liquid solution is transported across a first ion exchange barrier from the first chamber to a second chamber. The first ion exchange barrier has a first charge. The second chamber includes an ion exchange packing having a second charge that is an opposite polarity to the first charge. The volatile component reacts with the ion exchange packing to create a charged component in the second chamber. The charged component having a third charge that is a same polarity to the first charge. The ion exchange packing is regenerated by electrolytically generating a hydronium or a hydroxide.

A method, device, and system for removing a volatile component from a liquid solution for a chromatographic separation are described. The method includes the flowing of a liquid solution through a first chamber of the device. A volatile component in the liquid solution is transported across a first ion exchange barrier from the first chamber to a second chamber. The first ion exchange barrier has a first charge. The second chamber includes an ion exchange packing having a second charge that is an opposite polarity to the first charge. The volatile component reacts with the ion exchange packing to create a charged component in the second chamber. The charged component having a third charge that is a same polarity to the first charge. The ion exchange packing is regenerated by electrolytically generating a hydronium or a hydroxide.

A novel analytical system and method to analyze complex carbohydrates such as human milk oligosaccharides by low-temperature High-Performance Anion Exchange Chromatography with Pulsed Amperometric Detection and High-resolution Mass Spectrometry (HPAE-PAD-MS). The analytical system controls the temperature of the column, electrochemical detector, and ion removal device at or below 15° C. The HPAE-PAD workflow with high-resolution mass spectrometry provides useful molecular structure information. It facilitates the detection of milk oligosaccharides, particularly unknown structures, without the use of analytical standards.

The invention provides methods for quantifying a non-ionic surfactant in a composition comprising a polypeptide and the non-ionic surfactant, where the quantification exhibits reduced interference between the non-ionic surfactant and the polypeptide. Also provided are methods where the composition further includes N-acetyl tryptophan, and the quantification exhibits reduced interference between the non-ionic surfactant, the polypeptide, and N-acetyl tryptophan.

The invention provides methods for quantifying a non-ionic surfactant in a composition comprising a polypeptide and the non-ionic surfactant, where the quantification exhibits reduced interference between the non-ionic surfactant and the polypeptide. Also provided are methods where the composition further includes N-acetyl tryptophan, and the quantification exhibits reduced interference between the non-ionic surfactant, the polypeptide, and N-acetyl tryptophan.

First and second electrode liquid seal members are arranged between a first electrode and a second electrode. First and second ion exchange membranes are arranged between a first electrode liquid seal member and a second electrode liquid seal member. An eluent seal member is arranged between a first ion exchange membrane and a second ion exchange membrane. Ion exchange is performed between an eluent that passes through an eluent flow path of the eluent seal member from a separation column and an electrode liquid that passes through each of electrode liquid flow paths of the first and second electrode liquid seal members. In a first surface of the eluent seal member that comes into contact with the first ion exchange membrane, a first projection that surrounds the entire circumference of the eluent flow path to extend along the edge of the eluent flow path and projects toward the first ion exchange membrane is formed.