Oil products | Karl Fischer titrator AQ-300/MOICO-A19/EV-2000L - JM Science

Water Content in Oil Products by Karl Fischer Titration

Water contamination is one of the leading causes of lubricant degradation, corrosion, oxidation, and premature equipment failure. Even small amounts of moisture can reduce the performance of hydraulic fluids, transformer oils, lubricating oils, diesel fuel, aviation fuels, and other petroleum products.

Karl Fischer titration is the internationally recognized analytical method for determining water content over a wide concentration range, from only a few parts per million (ppm) to several percent. It provides the accuracy, repeatability, and sensitivity required for quality control, production, and maintenance laboratories.

This application describes moisture determination in oil products using the AQ-300 Coulometric Karl Fischer Titrator, MOICO-A19 Coulometric Karl Fischer Titrator, and the EV-2000L Oil Evaporator when samples cannot be injected directly into the titration cell.

Why Measure Moisture in Oil Products?

Routine moisture analysis helps laboratories:

Monitor lubricant condition
Detect water contamination before equipment damage occurs
Verify incoming raw materials
Improve transformer oil reliability
Maintain hydraulic system performance
Ensure fuel quality
Extend equipment service life
Meet ASTM and ISO quality requirements

Recommended Instruments

For routine moisture analysis, JM Science recommends:

AQ-300 Coulometric Karl Fischer Titrator – Ideal for trace moisture measurements from approximately 1 ppm to 5%.
MOICO-A19 Coulometric Karl Fischer Titrator – Advanced touchscreen system with data management, networking, and regulatory compliance features.
EV-2000L Oil Evaporator – Recommended for viscous oils, additive packages, greases, and samples that interfere with direct Karl Fischer analysis.

Sample Types

Typical applications include:

Lubricating oils
Hydraulic oils
Gear oils
Transformer oils
Turbine oils
Compressor oils
Engine oils
Diesel fuel
Gasoline
Aviation fuel
Kerosene
Crude oil fractions
Base oils
Synthetic lubricants
Biofuels

Direct Injection Method

Many clean petroleum products can be analyzed by directly injecting the sample into the Karl Fischer titration cell using a gas-tight syringe.

Advantages include:

Fast analysis
Minimal sample preparation
Excellent repeatability
High sensitivity
Fully automated endpoint detection

EV-2000L Oil Evaporator Method

Some oils contain additives or components that interfere with the Karl Fischer reaction or contaminate the titration cell.

Examples include:

Heavy lubricants
Greases
Highly viscous oils
Samples containing sulfur compounds
Additive-rich formulations

For these samples, the EV-2000L evaporates the moisture from the sample while a dry carrier gas transports only the water vapor into the Karl Fischer titration cell. This technique protects the measuring cell and produces highly reliable results without introducing interfering compounds.

Typical Results

Karl Fischer titration provides:

Excellent repeatability
High analytical sensitivity
Rapid analysis times
Reliable low-level moisture determination
Automatic calculation and reporting

Results are typically reported in:

ppm (mg/kg)
%
mg of water

Common Applications

Industries using this method include:

Petroleum refining
Lubricant manufacturing
Power generation
Aerospace
Automotive
Mining
Marine
Chemical manufacturing
Industrial maintenance laboratories
Fuel testing laboratories

Applicable Standards

Karl Fischer moisture determination is widely used with methods including:

ASTM D6304 – Water Determination in Petroleum Products
ASTM E1064 – Water in Organic Liquids
ASTM D4928 – Water in Crude Oil
ISO 12937 – Petroleum Products—Determination of Water

Always consult the latest version of the applicable standard for detailed procedures.

Why Choose JM Science?

JM Science has supplied Karl Fischer moisture analyzers to laboratories throughout North America for more than 37 years. Our systems combine high analytical performance with comprehensive application support for petroleum, lubricant, chemical, pharmaceutical, semiconductor, and food testing laboratories.

Whether your application requires direct injection or oven extraction, our specialists can recommend the most appropriate Karl Fischer solution for your sample type.