Experimental methods in chemical engineering: Gas chromatography—GC

Abstract

Gas chromatography (GC) separates volatile and semi‐volatile liquids and gases based on their affinity for a stationary phase, either a thin liquid or a polymer layer on a solid. A gaseous mobile phase carries the volatile compounds from an injection port to a column with the stationary phase and then to an amdetector. The most common detectors are based on mass spectrometry (MS), thermal conductivity, and flame ionization. A furnace houses the columns and maintains or ramps temperatures to increase the separation efficiency—reduce run time or increase peak separation (resolution). The analyst chooses the chemistry of the stationary phase and the physical structure of the columns based on the polarity and functional groups of the solute. Packed columns tolerate impurities better than capillary columns that have a greater separating power and bleed the functional groups less. Efficiency is best when the sample polarity matches the column polarity. High temperatures and contamination cause columns to bleed the active components, which reduces the resolution but might also introduce ghost peaks to the chromatogram. The Web of Science assigned 15 000 articles to chemical engineering that mention GC and gas chromatography as keywords. Since 2017, it has indexed close to 1000 new articles every year. A bibliometric analysis classifies these contributions into four clusters: (1) pyrolysis and biomass, (2) GC–MS and extraction, (3) lignin and aromatics, and (4) decomposition and kinetics.

tert‐butanol and hydrogen peroxide react over Amberlyst‐15 to form tert‐butyl hydroperoxide

“…So, low injection temperature and slow heating rates are suitable parameters for hydroperoxides. [ 31,32 ] We used both gas chromatography–mass spectrometry (GC–MS) and GC‐flame ionization detection (FID) to quantify the liquid products at different stages.…”

Sonocatalytic Biodiesel Transesterification to Produce a Lubricant

“…An Agilent 7890A GC-MS and a DB-Wax column (30 m × 0.250 mm × 0.25 μm) characterized both reactants and products through detection using a 5975C VL MSD with a triple-axis detector. We quantified the diester yield by calculating the relative response factor (RRF) by the effective carbon number (ECN) method (eqs and ). − We used this method since pure DE standards are not commercially available. The mass and the yield of the diester are determined from eqs and . RRF = A ISTD × m DE A DE × m ISTD RRF = EC N ISTD × M DE EC N DE × M ISTD m DE = RRF × A DE × m ISTD A ISTD = EC N ISTD × M DE EC N DE × normalM ISTD × A DE m …”

A Review of Weathering Studies in Plastics and Biocomposites—Effects on Mechanical Properties and Emissions of Volatile Organic Compounds (VOCs)

“…The retention rate of a molecule depends on its interaction with the stationary phase, with stronger interactions leading to higher retention. An inert gas transports the analytes through the capillary column to the detector, generating a mass spectrum for selected molecules [ 82 ].…”