A first mixer mixes solvents therein. A second mixer has a capacity different from that of the first mixer, and mixes solvents therein. A first separation column is associated with the first mixer. A second separation column is associated with the second mixer. A first valve enables switchover between a first communication state in which the first mixer and the first separation column communicate with a detector, and a second communication state in which the second mixer and the second separation column communicate with the detector. Only by switching the first valve, it is possible to switch between the first communication state and the second communication state. The internal capacity of a flow channel in the first communication state differs from that in the second communication state. Therefore, it is easy to perform analysis with different internal capacities.

A first mixer mixes solvents therein. A second mixer has a capacity different from that of the first mixer, and mixes solvents therein. A first separation column is associated with the first mixer. A second separation column is associated with the second mixer. A first valve enables switchover between a first communication state in which the first mixer and the first separation column communicate with a detector, and a second communication state in which the second mixer and the second separation column communicate with the detector. Only by switching the first valve, it is possible to switch between the first communication state and the second communication state. The internal capacity of a flow channel in the first communication state differs from that in the second communication state. Therefore, it is easy to perform analysis with different internal capacities.

The invention relates to a system and micro monitor apparatus, a space-, time-, and cost-efficient device to concentrate, identify, and quantify organic compounds in gas environments. The invention further relates to a method centered on gas chromatography for identifying and quantifying organic compounds in gas environments, using air as the carrier gas, without the need for a compressed pre-bottled purified carrier gas.

The invention relates to a system and micro monitor apparatus, a space-, time-, and cost-efficient device to concentrate, identify, and quantify organic compounds in gas environments. The invention further relates to a method centered on gas chromatography for identifying and quantifying organic compounds in gas environments, using air as the carrier gas, without the need for a compressed pre-bottled purified carrier gas.

A method for applying a heating sequence for a modulator includes, during a first period of time, heating a first heating zone disposed along a length of the modulator without heating a second heating zone to cause a sample trapped from a first transfer line at an entrance of the modulator to move from the first heating zone to the second heating zone. The method also includes, during a second time period, withdrawing the heating of the first heating zone to prevent the sample from entering the modulator from the first transfer line. During a third time period, the method includes heating the second heating zone without heating the first heating zone to reinject the sample into a second transfer line.

A method for applying a heating sequence for a modulator includes, during a first period of time, heating a first heating zone disposed along a length of the modulator without heating a second heating zone to cause a sample trapped from a first transfer line at an entrance of the modulator to move from the first heating zone to the second heating zone. The method also includes, during a second time period, withdrawing the heating of the first heating zone to prevent the sample from entering the modulator from the first transfer line. During a third time period, the method includes heating the second heating zone without heating the first heating zone to reinject the sample into a second transfer line.

The present disclosure relates to a method for detecting the contents of whey protein and casein, and/or the ratio thereof in milk powder by liquid chromatography-mass spectrometry. According to the method of the present disclosure, the characteristic peptide segments of whey protein and casein are selected and used for correction, and thus the accuracy and stability of detection of peptide segments by mass spectrometry using external standards are improved; in addition, the method of the present disclosure has the following advantages: easy to pretreat samples, low cost, a wide range of applicability, enable to perform quantitative detection of whey protein at one time, not affected by protein denaturation in the production process, no need to synthesize isotope internal standard, and avoiding influence of ionization efficiency and matrix in mass spectrometry detection by means of their own multiple characteristic peptide segment ratios.

The present disclosure relates to a method for detecting the contents of whey protein and casein, and/or the ratio thereof in milk powder by liquid chromatography-mass spectrometry. According to the method of the present disclosure, the characteristic peptide segments of whey protein and casein are selected and used for correction, and thus the accuracy and stability of detection of peptide segments by mass spectrometry using external standards are improved; in addition, the method of the present disclosure has the following advantages: easy to pretreat samples, low cost, a wide range of applicability, enable to perform quantitative detection of whey protein at one time, not affected by protein denaturation in the production process, no need to synthesize isotope internal standard, and avoiding influence of ionization efficiency and matrix in mass spectrometry detection by means of their own multiple characteristic peptide segment ratios.

For providing a column oven and chromatography capable of reliably preventing misconnection of a storage unit to a connecting part, the column oven includes: a hollow casing; a column unit including an analysis column, which is arranged in the casing and allows a mobile phase (Q) to flow through, and a storage unit, which is attached to the analysis column and stores data of the analysis column; multiple holding parts, which are arranged in the casing and hold the analysis column; a tabular fixing plate, which is arranged in the casing and fixes the respective holding parts to the casing; multiple connecting parts, which are arranged in the casing and connect the storage unit electrically and detachably; and a heating part, which heats the analysis column held by the holding parts in the casing. When viewing the analysis column from a side facing the fixing plate with the analysis column held by the holding parts, the connecting parts connected to the storage unit of the column unit including the analysis column are arranged adjacent to the analysis column.

For providing a column oven and chromatography capable of reliably preventing misconnection of a storage unit to a connecting part, the column oven includes: a hollow casing; a column unit including an analysis column, which is arranged in the casing and allows a mobile phase (Q) to flow through, and a storage unit, which is attached to the analysis column and stores data of the analysis column; multiple holding parts, which are arranged in the casing and hold the analysis column; a tabular fixing plate, which is arranged in the casing and fixes the respective holding parts to the casing; multiple connecting parts, which are arranged in the casing and connect the storage unit electrically and detachably; and a heating part, which heats the analysis column held by the holding parts in the casing. When viewing the analysis column from a side facing the fixing plate with the analysis column held by the holding parts, the connecting parts connected to the storage unit of the column unit including the analysis column are arranged adjacent to the analysis column.