A permeative amine/acid introduction device (PAID) is placed after a conventional KOH eluent suppressed conductometric anion chromatography (SCAC) system. The PAID converts the suppressed eluites from the acid form to the corresponding salt. For example, when the analytes are acids, they are converted to the corresponding ammonium salt (NR.sub.2H+HX.fwdarw.NR.sub.2H.sub.2.sup.++X.sup.) and allows very weak acids HX (pK.sub.a7.0) that cannot normally be detected by SCAC to be measured by a second conductivity detector following the PAID. Permeative reagent introduction is dilutionless, can be operated without pumps and provides good mixing with low band dispersion (as small as 30 L). An exemplary amine is diethylamine (DEA), which was chosen as the amine source due to its low pK.sub.b value (pK.sub.b 3.0), high vapor pressure, and low toxicity and low odor.

A permeative amine/acid introduction device (PAID) is placed after a conventional KOH eluent suppressed conductometric anion chromatography (SCAC) system. The PAID converts the suppressed eluites from the acid form to the corresponding salt. For example, when the analytes are acids, they are converted to the corresponding ammonium salt (NR.sub.2H+HX.fwdarw.NR.sub.2H.sub.2.sup.++X.sup.) and allows very weak acids HX (pK.sub.a7.0) that cannot normally be detected by SCAC to be measured by a second conductivity detector following the PAID. Permeative reagent introduction is dilutionless, can be operated without pumps and provides good mixing with low band dispersion (as small as 30 L). An exemplary amine is diethylamine (DEA), which was chosen as the amine source due to its low pK.sub.b value (pK.sub.b 3.0), high vapor pressure, and low toxicity and low odor.

Disclosed is a method for preparing a composition comprising factor VIII (FVIII) and von Willebrand factor (vWF), wherein the content of the von Willebrand factor (vWF) can be controlled by mixing the factor VIII (FVIII) with the von Willebrand factor (vWF) at an appropriate ratio after separately purifying the factor VIII (FVIII) and the von Willebrand factor (vWF) from plasma in a single process. The method can prepare and purify a composition comprising factor VIII (FVIII) and a varying content of von Willebrand factor (vWF) without increasing the amount of impurities other than the von Willebrand factor (vWF) compared to a method of purifying factor VIII (FVIII) separately, without significantly increasing the processing time (within 3 hours) compared to a method of purifying factor VIII (FVIII), and without changing the yield of factor VIII (FVIII).

A preparative purification apparatus capable of adjusting a mixing ratio of a mobile phase and an elution solvent contained in a solution to be collected. A liquid feeding unit which feeds an elution solvent to an inlet of a trap column; a flow path switching unit which selectively connects an outlet of the trap column to one of a waste liquid flow path or a recovery flow path; a liquid feed amount measurement unit; and a flow path control unit which performs a control such that the flow path switching unit is connected to the recovery flow path when the amount of the elution solvent fed to the trap column reaches a predetermined initial waste liquid amount, and thereafter, the flow path switching unit is connected to the waste liquid flow path at a timing of reaching a predetermined solution recovery amount.

A preparative purification apparatus capable of adjusting a mixing ratio of a mobile phase and an elution solvent contained in a solution to be collected. A liquid feeding unit which feeds an elution solvent to an inlet of a trap column; a flow path switching unit which selectively connects an outlet of the trap column to one of a waste liquid flow path or a recovery flow path; a liquid feed amount measurement unit; and a flow path control unit which performs a control such that the flow path switching unit is connected to the recovery flow path when the amount of the elution solvent fed to the trap column reaches a predetermined initial waste liquid amount, and thereafter, the flow path switching unit is connected to the waste liquid flow path at a timing of reaching a predetermined solution recovery amount.

Methods of maintaining narrow residence time distributions in continuous flow systems, particularly applicable to virus inactivation such as during a protein purification process. Fluid sample is introduced into an axial flow channel and caused to flow therein in discrete packets or zones to minimize residence time distribution and axial dispersion. Embodiments described herein obviate or minimize the need for using large tanks or reservoirs for performing virus inactivation during a protein purification process; reduce the overall time required for virus inactivation, and/or reduce the overall physical space required to perform the virus inactivation operation during a protein purification process, which in turn reduces the overall footprint for the purification process.

Methods of maintaining narrow residence time distributions in continuous flow systems, particularly applicable to virus inactivation such as during a protein purification process. Fluid sample is introduced into an axial flow channel and caused to flow therein in discrete packets or zones to minimize residence time distribution and axial dispersion. Embodiments described herein obviate or minimize the need for using large tanks or reservoirs for performing virus inactivation during a protein purification process; reduce the overall time required for virus inactivation, and/or reduce the overall physical space required to perform the virus inactivation operation during a protein purification process, which in turn reduces the overall footprint for the purification process.

The present disclosure relates to an enhanced multi-dimensional chromatography system and method using selectable At-Column Dilution to improve compatibility of the interface and transfer between the multiple dimensions. The use of At-Column Dilution (ACD) with multi-dimensional chromatography can provide greater retention of the diverted components on subsequent stationary phases, and increase the sensitivity and peak shape of the component(s) separated on subsequent dimensions.

A water purification apparatus includes a bottomed cylindrical container tank, a lid member for fluid-tightly closing an upper opening of the container tank, an upper filter which forms an upper space between the lid member and itself, a lower filter which forms a lower space between a bottom plate of the container tank and itself, a water passage pipe which passes through the upper and lower filters and which establishes a communication between the upper and lower spaces, and an ion-exchange resin loaded in a space defined by the container tank, the upper and lower filters and the water passage pipe. The lid member has a water supply pipe for supplying water to the upper space, and an overflow pipe which connects to the water passage pipe. A water conveyance pipe for discharging the pure water in the container tank to outside is connected to the lower space.

An ion suppressor includes ion exchange membranes between a pair of electrodes. Regeneration liquid channels are provided in the spaces between the electrodes and the ion exchange membranes, and an eluent channel is provided between the ion exchange membranes. In the space between the electrode and the eluent channel, an element that increases the resistance in the voltage application direction is disposed. For example, ion permeable membranes are disposed in contact with the ion exchange membrane, thereby increasing the resistance in the voltage application direction.