Described herein is method for testing an ion exchange chromatography device. The method includes monitoring both a binding and a non-binding species and determining their breakthrough point to determine a net breakthrough value. The method can be used to determine the integrity of the chromatography device, ensure that the chromatography device possesses the expected adsorbent capacity, and/or determine viral clearance of the chromatography device.

A measuring instrument including: a sensor unit outputting an alternating current signal having an amplitude corresponding to a physical amount of a measurement target; a reference signal output unit outputting a reference signal having the same frequency and the same phase as those of the alternating current signal; a multiplication unit multiplying the alternating current signal and the reference signal together; an A/D conversion unit disposed before or after the multiplication unit; and an integration unit integrating a digital signal which is output of the multiplication unit, for a predetermined time. It is possible to measure a value of the physical amount of the measurement target only with a delay of one cycle of the alternating current signal.

Systems and methods for inhibiting translocation of ions across ion exchange barriers include an eluent generator having an ion source reservoir with a first electrode, an eluent generation chamber with a second electrode, an ion exchange barrier disposed therebetween, and means for reversing the polarity of a voltage or current applied across the first and second electrodes. A first polarity voltage or current applied across the electrodes generates an electric field that promotes translocation of eluent counter ions from the reservoir across the barrier, where the counter ions combine with eluent ions electrolytically generated in the chamber. By reversing the polarity of the voltage or current across the electrodes, the resulting electric field inhibits translocation of counter ions across the barrier from the reservoir into the chamber. Reverse voltage or current bias reduces counter ion concentration in the resting chamber to prevent exhaustion of ion suppressor capacity during start up.

Systems and methods for inhibiting translocation of ions across ion exchange barriers include an eluent generator having an ion source reservoir with a first electrode, an eluent generation chamber with a second electrode, an ion exchange barrier disposed therebetween, and means for reversing the polarity of a voltage or current applied across the first and second electrodes. A first polarity voltage or current applied across the electrodes generates an electric field that promotes translocation of eluent counter ions from the reservoir across the barrier, where the counter ions combine with eluent ions electrolytically generated in the chamber. By reversing the polarity of the voltage or current across the electrodes, the resulting electric field inhibits translocation of counter ions across the barrier from the reservoir into the chamber. Reverse voltage or current bias reduces counter ion concentration in the resting chamber to prevent exhaustion of ion suppressor capacity during start up.

An ion exchange chromatography column contains an ion exchange stationary phase that includes a charged substrate, a plurality of first particles, and a plurality of second particles. The plurality of first particles each include first ion exchange groups and the first particles are ionically bound to the charged substrate. The plurality of second particles each include second ion exchange groups and the second particles are ionically bound to the charged substrate. The first particles having a first ion exchange group density, and the second particles having a second ion exchange group density. The first ion exchange group density is greater than the second ion exchange group density. The ion exchange chromatography column has a number of zones connected in series where each zone can have a varying level of first ion exchange groups and second ion exchange group from the inlet zone to the outlet zone.

An ion exchange chromatography column contains an ion exchange stationary phase that includes a charged substrate, a plurality of first particles, and a plurality of second particles. The plurality of first particles each include first ion exchange groups and the first particles are ionically bound to the charged substrate. The plurality of second particles each include second ion exchange groups and the second particles are ionically bound to the charged substrate. The first particles having a first ion exchange group density, and the second particles having a second ion exchange group density. The first ion exchange group density is greater than the second ion exchange group density. The ion exchange chromatography column has a number of zones connected in series where each zone can have a varying level of first ion exchange groups and second ion exchange group from the inlet zone to the outlet zone.

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 the first electrode liquid seal member and the second electrode liquid seal member. An eluent seal member is arranged between the first ion exchange membrane and the second ion exchange membrane. A plurality of first mesh members having different charge amounts are stacked in a first electrode liquid flow path of the first electrode liquid seal member. Each of the plurality of first mesh members is constituted by a first wire group composed of a plurality of first wires and a second wire group composed of a plurality of second wires crossing the first wire group. The plurality of first wire groups of the plurality of first mesh members respectively extend in different directions, and the plurality of second wire groups of the plurality of first mesh members respectively extend in different directions and extend in directions different from those of the plurality of first wire groups.

Methods, apparatuses and systems are described that are capable of simultaneously determining the presence, identities or levels of multiple analytes present in a single sample, by carrying out steps including denaturation, normalization, extraction, mixed-mode liquid chromatography and mass spectrometry, whereby the presence, identities or levels of analytes in the single sample are determined.

Methods, apparatuses and systems are described that are capable of simultaneously determining the presence, identities or levels of multiple analytes present in a single sample, by carrying out steps including denaturation, normalization, extraction, mixed-mode liquid chromatography and mass spectrometry, whereby the presence, identities or levels of analytes in the single sample are determined.

A reagent for use in the measurement of hemoglobins by liquid chromatography, the reagent comprising a nonionic surfactant selected from the group consisting of:

(i) polyoxyethylene (10) decyl ether; (ii) polyoxyethylene (6) 2-ethylhexyl ether; (iii) polyoxyethylene (9) isodecyl ether; (iv) polyoxyethylene (10) nonyl ether; (v) polyoxyethylene (16) isostearyl ether; (vi) polyoxyethylene (20) behenyl ether; and (vii) polyoxyethylene (20) polyoxypropylene (6) decyltetradecyl ether.