D6228-19 – Standard Test Method Technical Guide

🧪 Scope and Method Principle

ASTM D6228-19 specifies a standard test method for the determination of individual volatile sulfur-containing compounds in natural gas and gaseous fuels. The analysis is performed using gas chromatography (GC) equipped with a flame photometric detector (FPD) or a pulsed flame photometric detector (PFPD). The method employs capillary column chromatography for high-resolution separation of sulfur species such as hydrogen sulfide (H₂S), carbonyl sulfide (COS), mercaptans, and sulfides.

The detection range for sulfur is strictly defined. The detector is sensitive to absolute masses of sulfur ranging from 20 to 20,000 picograms (pg). Based on a standard 1 mL gas sample injection, this translates to a concentration range of 0.02 to 20 mg/m³ or 0.014 to 14 ppmv of sulfur. The method does not require the identification of every single individual sulfur species; the total sulfur content of the sample can be reliably estimated from the summation of all individual compounds detected. Unidentified peak compounds are calculated quantitatively as monosulfur-containing