A method for analyzing a gas sample conveyed in a drilling fluid involves liberating the gas sample from the drilling fluid, irradiating the gas sample with infrared radiation spanning a wavelength range in the near-infrared range, detecting absorption spectra associated with irradiating the gas sample, and determining a composition of the gas sample from the absorption spectra. The gas sample includes one or more of methane, ethane, propane, and butane, the detected absorption spectra are associated with irradiating each of the one or more of methane, ethane, propane, and butane, and the composition includes a concentration of any one or more of the methane, ethane, propane, and butane.