This standard covers the determination of the chemical composition of natural gas liquid streams where precise physical property data of the hexanes and heavier fraction is required. This procedure is applicable for liquid hydrocarbon mixes which may contain nitrogen and carbon dioxide and/or hydrocarbon complexes C1 through C10 that fall within the ranges listed in Table 1. This standard had previously only seen minor revisions since its adoption as a technical standard in 1986. In this revision, portions that had become obsolete and that did not reflect current industry practices were revised. In addition, the example calculations that utilize GPG 2145 to reflect the 2009 revision of GPA 2145 and all calculations related to those presented in GPA 2172 were removed and referenced to GPA 2172. Also, the QA/QC related material previously included in this standard have been removed and referenced to GPA 2198. The most significant changes to the standard involve updates to the method to maintain consistency with current technologies. NEW! ADDED IN 2017, FOR ELECTRONIC (PDF) ORDERS, YOU WILL ALSO RECEIVE A SAMPLE CALCULATIONS SPREADSHEET (EXCEL FILE) FOR THIS STANDARD.