An apparatus for performing liquid chromatography includes a chromatography column, and an insulating member surrounding the chromatography column wherein the insulating member is formed from a vacuum chamber surrounding the chromatography column. Another apparatus for performing liquid chromatography includes a chromatography column, and an insulating member surrounding the chromatography column, wherein the insulating member includes aerogel. Also described is a method of insulating a chromatography column comprising forming a jacket surrounding the chromatography column, and creating a vacuum chamber in an area between the jacket and the chromatography column.

The present invention discloses a method for judgment of cheddar cheese grade based on identification characteristic flavor compounds, comprising the following steps: selecting cheddar cheese of different grades as standard product, and extracting volatile flavor compounds from the standard product; using gas phase-sniffing device to screen out characteristic flavor compounds with higher flavor intensity from the volatile flavor compounds through aroma extract dilution analysis; proceeding with clustering of characteristic flavor compounds as screened out to obtain identification characteristic flavor compounds of cheddar cheese; measuring the concentration of identification characteristic flavor composition of cheddar cheese of known grade, and establish the training set for training of support vector machine; measuring the concentration of identification characteristic flavor composition of cheddar cheese to be tested, and inputting it into the support vector machine trained to judge the grade of cheddar cheese to be tested. The present invention aims to obtain the model of identification characteristic flavor compounds of cheddar cheese through statistical analysis, which is available for accurate judgment of cheddar cheese quality grade on this basis.

A pre-heater assembly for pre-heating a fluid, in particular in a fluid separation apparatus, wherein the pre-heater assembly comprises a capillary having a lumen and being configured for conducting the fluid, and a thermal coupling body contacting at least part of the capillary, having a value of thermal conductivity in a range between 8 W/(m K) and 100 W/(m K) and being arrangable so that heat generated by a heat source is supplied to the capillary via at least part of the thermal coupling body.

Techniques and apparatus for thermally controlled interfaces for separation devices and optical flow cell devices with minimized post-column volumes are described. In one embodiment, for example, a column-optical cell assembly may include an insulating device, a chromatography column arranged within the insulating device, and an optical flow cell in fluid communication with the chromatography column, the chromatography column arranged within a minimum distance of the optical flow cell.

A gas chromatograph includes a sample introduction portion and a heater block. A contact portion is fit into a first recess of a main body of the sample introduction portion. The heater block is fixed to and positioned with respect to the main body of the sample introduction portion by directly coming into contact with the contact portion provided on the main body of the sample introduction portion. For this reason, the heater block may be securely positioned with respect to the sample introduction portion.

A sensor module includes a sensor configured to detect a specific substance in a sample, a first channel, and a second channel The first channel supplies a first fluid as the sample to the sensor. The second channel supplies a second fluid different from the first fluid to the sensor. The second channel includes a second fluid buffer tank for holding the second fluid for a fixed time interval.

An apparatus for performing liquid chromatography includes a chromatography column, and an insulating member surrounding the chromatography column wherein the insulating member is formed from a vacuum chamber surrounding the chromatography column. Another apparatus for performing liquid chromatography includes a chromatography column, and an insulating member surrounding the chromatography column, wherein the insulating member includes aerogel. Also described is a method of insulating a chromatography column comprising forming a jacket surrounding the chromatography column, and creating a vacuum chamber in an area between the jacket and the chromatography column.

Techniques are described for accelerating thermal equilibrium in a chromatographic column. An apparatus comprises a chromatography column, and a plurality of temperature control units in thermal contact with the chromatography column. A method of performing liquid chromatography comprises setting an inlet of a chromatography column to a first temperature using a first temperature control unit in thermal contact with said inlet, setting an outlet of the chromatography column to a second temperature using a second temperature control unit in thermal contact with the outlet, wherein the first temperature is less than the second temperature; and injecting a sample into a liquid stream that flows through the chromatography column after the inlet is set at the first temperature and the outlet is at the second temperature.

The present invention discloses a method for judgment of cheddar cheese grade based on identification characteristic flavor compounds, comprising the following steps: selecting cheddar cheese of different grades as standard product, and extracting volatile flavor compounds from the standard product; using gas phase-sniffing device to screen out characteristic flavor compounds with higher flavor intensity from the volatile flavor compounds through aroma extract dilution analysis; proceeding with clustering of characteristic flavor compounds as screened out to obtain identification characteristic flavor compounds of cheddar cheese; measuring the concentration of identification characteristic flavor composition of cheddar cheese of known grade, and establish the training set for training of support vector machine; measuring the concentration of identification characteristic flavor composition of cheddar cheese to be tested, and inputting it into the support vector machine trained to judge the grade of cheddar cheese to be tested. The present invention aims to obtain the model of identification characteristic flavor compounds of cheddar cheese through statistical analysis, which is available for accurate judgment of cheddar cheese quality grade on this basis.

A fluidic block has a thermally conductive body with a first end and a second end opposite the first end. The body has a cutout portion formed therein between the first and second ends. The cutout portion partitions the body into a first region, a second region, and a thin region between the first and second regions. The cutout portion produces a thermal break between the first and second regions. The thermal break operates to guide a heat flow between the first and second regions through the thin region. A thermally conductive chromatography tube extends through the first, second, and thin regions from the first end to the second end of the body. The tube is in thermal communication with the body. A section of the tube may run in a transverse direction across the body in the thin region of the body.