Determination of sulphur in fuel oils by absorption spectrometry of electrothermally generated carbon sulphide molecules

Molecular absorption spectra of CS are observed during the vaporization of crude and fuel oils in an electrothermal atomizer. The CS absorbance at 257.6 nm is used to determine the sulphur content of the oil, based on measurements in a conventional electrothermal atomic absorption spectrometer. The results for various fuel oils generally agree with those obtained by x-ray fluorescence spectrometry (ASTM D2622). The detection limit referred to the undiluted oil is 50 mg kg^?1, and the repeatability is 3% at the 250 mg kg^?1 level. Some oils exhibit uneven vaporization of sulphur species.