PIN PETROCHEMICAL CHEMICAL & ENERGY Publication

Accurate measurement of hydrogen sulfide (H₂S) is essential for both safety and process reliability. H₂S is highly toxic — exceeding the odour threshold at just 3–5 ppm and posing severe health risks beyond 10 ppm. At concentrations above 1000 ppm, fatality can occur within minutes. Beyond its health hazards, H₂S is also highly corrosive, capable of damaging refinery equipment and infrastructure at rates of up to 10 mm per year.

Sulfimax GX go
Sulfimax GX go

To meet these challenges, ECH Elektrochemie Halle developed the Sulfimax GX, a versatile analyser designed for full compliance with key international test methods:

  • ASTM D8536-25: Determination of available sulfide in water and wastewater by gas extraction.
  • IP 570, (Procedure B): Determination of H₂S in liquid petroleum products.
  • ASTM D7621 (Procedure B): Determination of H₂S in crude oil, fuel oils, and other petroleum fractions.

Multi-Matrix Application

The Sulfimax GX enables reliable H₂S quantification across a wide range of samples:

  • Water & Wastewater → compliant with ASTM D8536-25, using acidification and gas extraction to generate and measure H₂S down to 0.01 ppm.
  • Liquid Petroleum Products (crude oil, gasoline, diesel, marine fuels) → analysed according to IP 570 (Procedure B) and ASTM D7621 (Procedure B), ensuring results that meet industry standards.
  • Solid Products (bitumen, tar, elemental sulfur) and Gas Products (LPG, NG, LNG, mixed gases) → measured with the headspace and LPG sampling modules.

Methodology & Detection

Using an electrochemical detector with an advanced gas extraction system, the Sulfimax GX measures H₂S across a broad dynamic range (0.01–10,000 ppm) with typical measurement times of ~5 minutes. Potential interferences, such as mercaptans, are eliminated through a dedicated white oil extraction step. After analysis, H₂S is safely neutralised in an activated carbon filter, eliminating the need for a fume hood.

For petroleum and solid products, the newly revised Vario headspace module allows controlled heating (up to 180 °C) to liberate H₂S from the sample. The Vario module also includes a new autosampler, enabling fully automated analysis for both IP 570 (Procedure B) and ASTM D7621 (Procedure B) procedures. For aqueous matrices, the system follows ASTM D8536-25, where samples undergo phosphoric acid acidification to release H₂S before detection.

Configurations

The Sulfimax GX is available in multiple formats to meet laboratory, portable, and online monitoring needs:

  • Sulfimax GX Lab – Bench-top system with Vario headspace, autosampler, and LPG options.
  • Sulfimax GX Go – Portable system with handle and optional portable headspace/LPG kits.
  • Sulfimax GX Online (ATEX) – Continuous analyser for petroleum applications in hazardous zones.
  • Sulfimax GX Online (Water) – Continuous H₂S monitoring in wastewater and aqueous samples.
  • Sulfimax GX Online (Gas) – Continuous analyser for natural gas and other gaseous mixtures.


Original: 
PIN PETROCHEMICAL CHEMICAL & ENERGY