How to test oleic acid value?

How to test oleic acid value?

‌Determination and Calculation of Acid Value in Oleic Acid‌

‌I. Determination Methods‌

‌Titration Method (Standard Method)‌

‌Principle‌: Neutralize free fatty acids in oleic acid with potassium hydroxide (KOH) standard solution, using indicator color change to determine the endpoint.

‌Reagents & Equipment‌:

Potassium hydroxide ethanol solution (concentration ≤0.02 mol/L)

Isopropanol (or ethanol-ether mixture)

BTB (bromocresol green) indicator

Precision balance, burette, conical flask

‌Procedures‌:

‌Blank Test‌: Titrate isopropanol solution until color changes from yellow to green, record KOH volume consumed.

‌Sample Titration‌: Mix test oil sample (5g) with isopropanol, titrate with KOH until color change, record volume difference.

‌Automated Determination (Optional)‌:

Use fully automated acid value tester (e.g., GDSZ-402A) for endpoint determination via colorimetric method.

‌II. Calculation Formula‌

Acid value (mg KOH/g) =

V×C×56.11mmV×C×56.11​

‌V‌: Volume of KOH consumed (mL)

‌C‌: KOH solution concentration (mol/L)

‌m‌: Mass of oil sample (g)

‌56.11‌: Molar mass of KOH (g/mol)

‌III. Precautions‌

‌Reagent Purity‌: Isopropanol and KOH must be high-purity; distilled water ≤5 ppm.

‌Environmental Control‌: Humidity ≤85%, temperature 15–30°C.

‌Data Validation‌: Standard acid value range for oleic acid: 196.0–204.0 mg KOH/g; retest if exceeded.

SH108 automatic oleic acid level meter complies with the requirements stipulated in the People's Republic of China standard GB/T 264 "Determination of the acid value of petroleum products" and GB7599,

The instrument adopts blue LCD large screen display, Chinese menu, no marker button.

Microcomputer automatic measurement, automatic printing, the test process to achieve computer automation, intuitive and simple operation.

Using magnetic stirring, no noise, safe and reliable, compact size.

It can meet the needs of oil refineries, power plants and scientific research units, and is one of the essential instruments for oil analysis and quality inspection.