Neue ASTM D8045: Thermometrische Säurezahlbestimmung in Rohöl

The ASTM has released a new method describing the measurement of the Acid Number (AN) in crude oil and petroleum products by thermometric titration.

Acidity is an important quality parameter in the commercial transaction of crude oil and is usually determined by potentiometric titration (in accordance with ASTM D664). This method, however, involves the risk of matrix components interfering with the measurement and requires complex and time-consuming maintenance procedures for the sensor.

With the new thermometric method, you can obtain more robust and reproducible results faster and more easily.

Warum thermometrische 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.

Berechnen Sie Ihr Einsparpotential!

Ihr Probendurchsatz

Kosten für Lösungsmittel

D664 benötigt 120 mL Lösungsmittel pro Probe
D8045 nur 30 mL pro Probe

Einsparpotential mit 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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