This test method is a standard procedure for the determination of saturates, olefins, aromatics and oxygenates in unleaded petrol using gas chromatography and vacuum ultraviolet detection (GC-VUV). Concentrations of compound classes and certain individual compounds are determined by mass fraction % (m/m) or volume fraction % (V/V). The concentration ranges for which precision has been determined are as given in Table 1. NOTE For the purposes of this document, the terms % (m/m) and % (V/V) are used to represent respectively the mass fraction and the volume fraction, respectively. The method is found to be applicable to other oxygenates including isopropanol, iso-butanol, tert-butanol, n-propanol, acetone, tert-pentanol and di-isopropyl ether (DIPE), however precision has not been determined. Individual hydrocarbon components are typically not baseline-separated by the procedure described in this test method. The coelutions are resolved at the detector using VUV absorbance spectra (Annex A) and deconvolution algorithms. While this test method reports by mass fraction % (m/m) or volume fraction % (V/V) for several specific components that can be present in unleaded petrol, it does not attempt to speciate all possible components that can occur in unleaded petrol. In particular, this test method is not intended as a type of detailed hydrocarbon analysis (DHA). This test method has been tested for unleaded petrol according EN 228 [1]; the method can apply to petrol blending streams but has not been extensively tested for such applications. WARNING The use of this document can involve hazardous materials, operations and equipment. This document does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this document to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use.