A bilateral study for the establishment of comparability in the measurement of ethanol in bioethanol fuel using isotope dilution mass spectrometry

A bilateral comparative study between two metrology institutes was conducted for the determination of ethanol in bioethanol fuel by isotope dilution mass spectrometry. Measurement procedures were independently developed by the Health Sciences Authority (Singapore) and the National Institute of Metrology (People??s Republic of China). The methods used included headspace gas chromatography?Chigh-resolution mass spectrometry, headspace gas chromatography?Cmass spectrometry (GC-MS) and direct injection to GC-MS. An investigation of all potential sources of uncertainty, including a component of uncertainty due to the effect of using different instruments such as gas chromatography?Cflame ionization detector method, commonly adopted for the analysis of organic volatiles, was carried out. The results of the analyses are consistent within the associated measurement uncertainty of each laboratory, reported at approximately 95% confidence level.