High-precision analysis of ethanol in bioethanol by gas chromatography with flame ionization detector

This paper describes the establishment and validation of gas chromatography-flame ionization detector (GC-FID) method for the determination of ethanol amount fraction in bioethanol samples. A general view of the development and optimization of the method is presented. The main aim of this study is the calculation of validation parameters. Selectivity of the method was determined. Linearity (R ²?>?0.999) was obtained in the range from 9.0 to 3040???g of ethanol per sample (because the mass of the test sample used was around 200?mg, this corresponds to 45?C2200???g?g^?1). The method showed good recoveries (average 99.0?%), and the relative standard deviation for repeatability and intermediate precision was 4.5 and 5.5?%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) were calculated as 10 and 30???g?g^?1, respectively. The uncertainty budget was finally done according to the ??Guide to the Expression of Uncertainty in Measurement?? (GUM), and the relative expanded uncertainty was 4.8?% at coverage of k?=?2.