9027.20.80.30 - Gas chromatographs

This classification covers gas chromatographs, which are sophisticated analytical instruments designed to separate, identify, and quantify components within a gas mixture. Gas chromatography operates by introducing a sample into a carrier gas stream, which then passes through a separation column containing a stationary phase. Different components of the sample interact with the stationary phase to varying degrees, causing them to elute from the column at different times. Detectors at the column's exit then measure the separated components, generating a chromatogram that serves as a fingerprint for analysis.

Distinguished from its sibling category, "Liquid chromatographs" (9027.20.80.60), this classification specifically pertains to instruments utilizing a gaseous mobile phase. Liquid chromatographs, in contrast, employ a liquid mobile phase. This fundamental difference in the nature of the mobile phase dictates the design, operational principles, and the types of samples and analytes each instrument is best suited to analyze.

As this HTS code represents a leaf node, there are no further subcategories. Classification within this code is therefore determined by the instrument's primary function as a gas chromatograph. Examples of items falling under this category include standalone gas chromatographs, as well as integrated systems primarily configured for gas chromatographic analysis, regardless of whether they are equipped with common detectors like flame ionization detectors (FID), thermal conductivity detectors (TCD), or mass spectrometers (MS), when the primary analytical method is gas chromatography.