A gas analysis device and a gas analysis method for performing measurement in a direct mode and a trap mode without carrying out a complicated control. The gas analysis device includes a branching section that branches a target gas, a mass spectrometer performing mass spectrometry of one branched target gas, a trap section holding the other branched target gas, a gas chromatograph analyzing the other branched target gas, and a controller controlling the flow path of the one branched target gas and the other branched target gas. The branching section is controlled so that, while a thermal analysis is performed by a thermal analysis device, the branching section continuously branches the supplied target gas and discharges the one branched target gas and the other branched target gas, and when the thermal analysis is completed, the other branched target gas held by the trap section is supplied to the gas chromatograph.

Methods for isolating proteins from solution by precipitation and compositions generated thereby are provided. A nonvolatile precipitation agent is added to an aqueous protein solution at a low concentration. Water is then removed from the resulting solution until the precipitant and the protein content of the solution increase to a concentration that provides the desired segregation of proteins between supernatant and precipitate. Additional water can be removed from the supernatant to provide additional fractionation. Water can be removed by evaporation (e.g. under reduced pressure) and/or diafiltration.

Methods for isolating proteins from solution by precipitation and compositions generated thereby are provided. A nonvolatile precipitation agent is added to an aqueous protein solution at a low concentration. Water is then removed from the resulting solution until the precipitant and the protein content of the solution increase to a concentration that provides the desired segregation of proteins between supernatant and precipitate. Additional water can be removed from the supernatant to provide additional fractionation. Water can be removed by evaporation (e.g. under reduced pressure) and/or diafiltration.

A chromatographic apparatus for online enrichment of trace and ultra-trace components and an analytical method using the same. The apparatus includes an injection system, a vaporizing chamber, an enrichment system, a thermal box, a sample collection system, a focusing trap, a chromatographic analytical column system, a detector and an electronic control system. The method includes steps of sample enrichment, thermal desorption and back flushing, which are performed through a combination of a four-way valve and an electronic switch valve box.

A chromatographic apparatus for online enrichment of trace and ultra-trace components and an analytical method using the same. The apparatus includes an injection system, a vaporizing chamber, an enrichment system, a thermal box, a sample collection system, a focusing trap, a chromatographic analytical column system, a detector and an electronic control system. The method includes steps of sample enrichment, thermal desorption and back flushing, which are performed through a combination of a four-way valve and an electronic switch valve box.

A water removal method for gas concentration sampling, and a sampling method and device. The water removal method comprises: removing water from a sample gas by means of a first cold trap tube filled with a hydrophilic material, and then concentrating the sample gas by means of a concentration cold trap tube; then by means of a carrier gas, conveying components desorbed by the first cold trap tube under a heating state to a second cold trap tube that is in a cooled state and that is filled with a hydrophobic organic adsorbent material, and adsorbing organic substances in the components desorbed by the first cold trap tube: by means of the carrier gas, bringing the moisture desorbed by the first cold trap tube out of the second cold trap tube, and then by means of the carrier gas, conveying residual components desorbed by the first cold trap tube and the second cold trap tube under the heating state to the concentration cold trap tube for concentration.

A water removal method for gas concentration sampling, and a sampling method and device. The water removal method comprises: removing water from a sample gas by means of a first cold trap tube filled with a hydrophilic material, and then concentrating the sample gas by means of a concentration cold trap tube; then by means of a carrier gas, conveying components desorbed by the first cold trap tube under a heating state to a second cold trap tube that is in a cooled state and that is filled with a hydrophobic organic adsorbent material, and adsorbing organic substances in the components desorbed by the first cold trap tube: by means of the carrier gas, bringing the moisture desorbed by the first cold trap tube out of the second cold trap tube, and then by means of the carrier gas, conveying residual components desorbed by the first cold trap tube and the second cold trap tube under the heating state to the concentration cold trap tube for concentration.

A method and system for sample analysis involve a temporally-resolving separation of sample components. In the method, solvent vapors are condensed prior to entering a temporally-resolving separator, a GC column, for example, and solvent-depleted vapors are directed to the separator where constituents are resolved in time. A system for analyzing a sample comprises an injection port, a temporally-resolving separator (e.g., a GC column) and a conduit connecting the two. The injection port is at a temperature sufficiently high to vaporize the solvent and analytes present in a sample. The conduit is configured and/or operated to condense the solvent, while maintaining the analytes in the vapor phase.

A method and system for sample analysis involve a temporally-resolving separation of sample components. In the method, solvent vapors are condensed prior to entering a temporally-resolving separator, a GC column, for example, and solvent-depleted vapors are directed to the separator where constituents are resolved in time. A system for analyzing a sample comprises an injection port, a temporally-resolving separator (e.g., a GC column) and a conduit connecting the two. The injection port is at a temperature sufficiently high to vaporize the solvent and analytes present in a sample. The conduit is configured and/or operated to condense the solvent, while maintaining the analytes in the vapor phase.

A thermal conductivity detector includes a first pipe path that houses a filament, a second pipe path and a third pipe path that connects the first pipe path to the second pipe path. In the third pipe path, first, second and third gas lead-in portions are arranged in this order from the first pipe path toward the second pipe path. A carrier gas is led to the first and third gas lead-in portions alternately, and a sample gas is led to the second gas lead-in portion. The distance between the second and third gas lead-in portions is equal to or smaller than 1.3 times of a maximum dimension of an opening formed at the second gas lead-in portion. At least part of the third pipe path between the second gas lead-in portion and the third gas lead-in portion has a cross sectional area that is equal to or smaller than an area of the opening formed at the second gas lead-in portion.