Testing Sulphur Contamination In Diesel

Dieselll is normally analysed in a laboratory for a variety of chemical and physical tests to monitor quality and compliance with various regulations. The introduction of the BS VI emission norms and a spike in fuel prices have forced the industry to look at alternative sources of cheaper fuel. The high demand has given rise to something we call at Chem-Tech Laboratories “Synthetic Diesel” or “Doctored Fuel”. As the name suggests synthetic or doctored is something that is manufactured in a not-so-normal way.

This fuel is highly contaminated and is currently being sold in the market as “Biofuel “ or “Biodiesel”.

Diesel can be contaminated with other fuels and solvents, kerosene, base oils & other chemicals having similar density and viscosity properties. In India after the introduction of BS VI fuel and the increase in diesel pricing, various industries have started using synthetically manufactured diesel containing the above-mentioned products.  Chemically this synthetically manufactured diesel is very similar to BS VI diesel but because enough quality control activities are not conducted during manufacturing it has very high proportions of Chloride & Sulphur content, along with other issues like higher boiling range, higher particulate matter and higher carbon residue forming tendency.

All these contaminants which come from synthetic diesel have various detrimental effects on the fuel system, DPF & SCR. There has been a huge amount of spike in the failure rate amongst all the BS VI equipment manufacturers owing to the wide-scale use of this synthetic fuel.

Despite all these positives, there are challenges when it comes to using the best quality diesel for vehicles, equipment, etc. The high Sulphur level in Diesel is always a concern. It leads to an increase in particulate matter, NOx emissions, corrosion to engine parts, clogging up fuel systems and more. -High sulphur has detrimental effects on the SCR system.

Now, you can check the high level of sulphur in the diesel you use anytime, anywhere. Chem-Tech Laboratories, the best Fuel Testing laboratory in India, has designed an exclusive Sulphur Field Test Kit. You can use it to determine the content of sulphur in the fuel. – The kit will help you identify the quality of the fuel to BS-VI specifications wrt the sulphur content. Higher sulphur will affect the fuel systems & SCR system, which will result in failure and downtime.

The kit contains all the reagents, chemicals & accessories you need for the testing. Let’s check out how to perform the test.


Reagents, Chemicals & Accessories

1. Glass Vial containing white PTFE septa. (Marked in the Kit as Glass Vial)

2. Solution – A – Clear Bottle 100 ml – (Marked in the Kit as Solution A)

3. Standard Diesel – 10 PPM – (Marked in the Kit as Standard Diesel).

The Sulphur Test Kit Consists of the following items:

1. 2 Vials with Septa ( 10 can be given if required to test up to 5 samples)

2. 2 Pair of Gloves

3. 1 Bottle containing standard diesel

4. 1 Bottle containing the Acid Solution

5. Instruction Page & SOP

Procedure for Testing

1. Take accurately 5ml of the test sample (Diesel) in a clear glass vial containing the septa. For comparison take 5 ml 10 PPM diesel in another glass vial containing the septa

2. Add accurately 10 ml of Solution- A into both the vials without removing the septa.

3. Tightly close the glass vials and shake for 5-10 seconds.

4. Keep the vials aside for 15 minutes exactly.

5. At the end of 15 minutes, compare the colour of the standard diesel vial against that of the sample vial.

6. If the colour is lighter compared to a standard fuel vial, it indicates the presence of a higher amount of sulfur content in diesel

7. Refer to the below chart for colour references w.r.t the bottom layer.


  • The method is completely validated for field samples containing more than 20 – 25 PPM of sulphur.
  • The lighter the shade in the results, the higher the Sulphur PPM level.
  • The samples which have more than 20 – 25 PPM of sulphur can be easily identified in the field.
  • If enough care is taken by the field team accurate determination can help the user understand the fuel quality.

Choose Sulphur Field Test Kit by Chem-Tech!

Founded in the year 1995, Chem-Tech Laboratories is a leading fuel testing laboratory in India. You can trust our NABL Accredited Chemical Testing Laboratory for accurate, reliable results. Using our Diesel Testing and Analysis, we ensure that the fuel in the equipment is of high quality. Our diesel analysis quality programs are designed to check whether the diesel used in the engine meets regulations and OEM specifications. Chem-Tech has state-of-the-art lab technology and experts to help you maintain the quality of diesel you use. Get in touch with us to learn more about our Sulphur Field Test Kit and request a quote!

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