New ASTM D8045: Thermometric acid number determination in crude oil

The ASTM has released a new method for Acid Number (AN) determination in crude oil and petroleum products by thermometric titration.

Compared with potentiometric titration (ASTM D664), this method is more robust, faster, and simpler.

Above all, this method will save you money, as you will need less solvent per analysis.

> See how much you can save …

Petroleum quality testing with ASTM D8045

Why go with thermometric titration?

  • Robust:
    Oil matrix does not interfere with the measurement.

  • Fast:
    Analysis in one third of the time (compared with potentiometric titration).
  • Simple:
    Sensor requires no maintenance or conditioning.
  • Inexpensive:
    Less solvent and reagent per analysis.

Calculate your savings!

Your throughput

Your solvent costs

D664 requires 120 mL of solvent per sample.
D8045 requires 30 mL of solvent per sample.

Your savings with ASTM D8045


It's all in the numbers: potentiometric vs. thermometric titration

using potentiometric titration
using thermometric titration
Volume of solvent required for analysis
125 mL
30–35 mL
Electrode conditioning
3–5 min
Not necessary
Electrode storage
LiCl in ethanol
Titration duration (averaged) 132–268 s  45–73 s
Method repeatability when measuring 1.0 mg KOH/g
in crude oil
Not established 0.07 mg KOH/g
Method reproducibility when measuring 1.0 mg KOH/g
in crude oil
Not established 0.31 mg KOH/g

Thermometry in the refinery process

Watch this video to learn more about the benefits of thermometric titration in the refinery process. 

What our customers think …

"A typical thermometric titration takes just about two minutes. Moreover, the electrode does not need to be regenerated …"

Thomas Fischer, laboratory manager at Oel Check GmbH, Brannenburg, Germany.

How does thermometric titration work?

Thermometric titration measures the temperature change in the titration solution (resulting from the reaction enthalpy) rather than the potential change. This technique can therefore be applied for difficult samples or matrices where potentiometric titration is difficult or not feasible.

As thermometric titration uses a temperature sensor and not an electrode, the sample matrix does not interfere with the measurement and sensor handling is as easy as it gets.

> Learn more about our Titrotherm for thermometric titration …

> Learn more about the Thermoprobe temperature sensor …


Interested? Get in touch to learn more …

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