Satisfying ASTM D8396 Requirements

Introduction

In response to the need for standardized compositional characterization of emerging aviation fuels, ASTM Method D8396— "Standard Test Method for Group Types Quantification of Hydrocarbons in Hydrocarbon Liquids with a Boiling Point between 36 C and 343 C by Flow Modulated GCxGC-FID"— o o was first approved in 2022. This application note describes how to use a simple workflow with the LECO Paradigm system to fulfill the requirements of the ASTM D8396 test method to quantitatively determine mass % of total n-paraffins, iso-paraffins, naphthenes, 1-ring aromatics, and 2-ring aromatics using reverse-fill flush flow modulated comprehensive two-dimensional gas chromatography–flame ionization detection (GCxGC-FID). Understanding of bulk composition is crucial for fast-track certification of synthetic aviation fuels as outlined in ASTM D4054, and the more accurate group-type analysis results provided by GCxGC assist with streamlining the acceptance process. GCxGC clearly resolves aliphatic regions from aromatic ones, creating bands of similar compounds which allow for general classification of chemical components based on structural elements and boiling point behavior with only a single-channel detector. When FID is used, area % values from groups of peaks can be used to quantify mass % composition of a sample.