Development of pyrolysis–GC with selective detection: coupling of pyrolysis–GC to atomic emission detection (py–GC–AED)

Abstract

Atomic emission detection (AED) is one of the most powerful detectors available for GC due to its unique selectivity and sensitivity to a wide range of elements. The coupling of py–GC to AED should therefore have many applications in fuel, forensic and polymer sciences. In this study on-line py–GC–AED has been developed for the analysis of volatile organic compounds (VOC) (C 1–C 8), evolved from a range of samples including coal, biomass, waste tyres, and plastics. An off-line py–GC–AED system, using an intermediate trapping and focussing method with a programmed temperature vaporisation (PTV) injector has also been developed for the selective trapping of VOC. The positive identification of sulphur and oxygen containing compounds in coal, biomass and tyre pyrolysis products has been demonstrated. The technique is very sensitive for sulphur, but less sensitive to oxygen and nitrogen compounds. The development of a ‘closed’ injection system using a sequence of valves significantly improved sensitivity for all elements. The operation of the two techniques is discussed in terms of both instrument constraints and detector breakthrough.