Diene Value Analyser: A Fast, Reliable and Automated Alternative to UOP 326

Diene Value (DV) is a key parameter in refining and petrochemical processes. Even small amounts of conjugated dienes can lead to product instability, catalyst issues and costly downtime. The traditional UOP 326 method is widely used, but it involves manual steps, hazardous chemicals and offers limited sensitivity. To make DV testing faster, safer and more reliable, Da Vinci Laboratory Solutions developed the Diene Value Analyser — a fully automated and precise alternative that determines DV in just 5 minutes.

Automated Diels–Alder Technology

The DVLS Diene Value Analyser is based on an Agilent HPLC stack and uses a Diels–Alder reaction with a selective colourimetric reagent to quantify total diene content through a decrease in UV/Vis absorbance. The automated HPLC platform eliminates wet chemical handling and manual labour, reducing operator exposure and minimising workflow variability. The system includes an isocratic pump with degassing, an automatic liquid sampler, a UV/Vis detector, the DVLS Reaction Module for controlled heating and CDS software for fully automated data processing. 

Optimised Reaction Module for Maximum Precision

The DVLS Reaction Module ensures stable and repeatable reaction conditions through precise temperature control and uniform heat distribution across an inert reaction coil. Installed seamlessly between the autosampler and detector, the module integrates smoothly into the HPLC stack. A built-in cooling zone at the coil outlet ensures reagents and products are cooled before entering the UV/Vis detector. The oven supports temperatures up to 225 °C (437 °F). 

Proven Performance Across Multiple Analytical Techniques

Tests with pygas samples using the DV Analyser were compared with UOP 326, GC-MS/FID and GC-VUV. The results demonstrate strong correlation with GC-MS/FID and GC-VUV, while also showing better recovery than the traditional UOP method. The DV Analyser consistently detects Diene Values from 0.5–100, outperforming the UOP method in both speed and low-level detection across all sample types.

Key Features & Benefits

• 5 minute analysis time – Ideal for process monitoring and quality control
• Fully automated workflow – Eliminates manual UOP 326 steps and reduces operator handling
• High sensitivity (<0.5 DV) – Enables trace level detection of reactive dienes
• Wide detection range (0.5–100 DV) – Suitable for a broad range of petrochemical streams
• No interference from alcohols – Ensures accurate and reliable DV quantification
• Minimal sample and reagent use – Only 1.5 mL required, improving operator safety
• Excellent repeatability (RSD <4%) – Ensures consistent and reproducible results 

Learn More

Interested in automated Diene Value analysis? Contact Da Vinci to learn how the DVLS Diene Value Analyser can enhance process stability, product quality and laboratory.

Download the flyer for more information on the Diene Value analysis.