New Buyer’s Guide explains how gas chromatography is used to measure LPG composition

LPG is bought, sold and distributed based on composition. The balance of propane, butane and related hydrocarbons determines how the fuel behaves during storage, transport and end use. Because of this, LPG cargoes are routinely analysed before entering the supply chain to confirm that they meet the required specification.

The new LPG Composition Testing by Gas Chromatography — Buyer’s Guide explains how laboratories measure LPG composition and how those measurements support product specification checks, blending operations and quality control throughout the supply chain.

Gas chromatography is widely used for LPG testing because it separates the hydrocarbons present in the fuel and measures each component individually. Typical analyses quantify compounds such as propane, propene, isobutane, n-butane, butenes and pentanes. The relative proportions of these hydrocarbons define the overall LPG composition and influence properties such as vapour pressure and volatility.

The guide walks through where LPG composition testing takes place in practice. Import terminals commonly analyse cargo before offloading to confirm that the propane–butane ratio matches contractual specifications. Storage and blending facilities monitor composition during storage or blending operations, while distribution depots may verify product composition before transfer to road tankers or cylinder filling systems.

Inside the guide, readers will learn:

• Where LPG composition analysis is typically performed across the supply chain
• The hydrocarbons measured during LPG GC analysis
• Industry standards used for LPG testing, including ASTM D2163, ASTM D2598 and EN 589
• How LPG samples are introduced into a gas chromatograph as either liquid or vapour
• The key components of a GC system used for LPG composition measurement
• Practical factors laboratories consider when selecting a GC configuration

The guide also explains how LPG composition data is used beyond basic quality checks. In many cases, the measured hydrocarbon distribution is used to calculate product properties such as density or vapour pressure. Standards such as ASTM D2598 define how these properties are derived from compositional analysis.

For laboratories involved in LPG import, storage, blending, or distribution, gas chromatography provides the compositional data needed to verify product quality and ensure compliance with specifications.

Download the LPG Composition Testing Buyer’s Guide today.

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