Hyphenated structural identification of additives in transmission fluids

Area of Science:

• Analytical Chemistry
• Materials Science
• Tribology

Background:

• Transmission fluids and lubricants reduce friction in mechanical systems.
• Additives are crucial for enhancing lubricant performance and lifespan.
• Accurate identification of lubricant additives is essential for quality control and performance optimization.

Purpose of the Study:

• To develop and demonstrate a hyphenated analytical technique for structural identification of transmission fluid additives.
• To identify a specific class of antioxidant additives in transmission fluids.
• To showcase the efficacy of combining supercritical fluid chromatography (SFC), Nuclear Magnetic Resonance (NMR) spectroscopy, and Mass Spectrometry (MS).

Main Methods:

• Utilized supercritical fluid chromatography (SFC) for rapid separation of transmission fluid additives within 10 minutes.
• Employed SFC coupled with proton Nuclear Magnetic Resonance (¹H NMR) spectroscopy for structural elucidation.
• Integrated mass spectrometry (MS) data to complement SFC-¹H NMR analysis for comprehensive identification.

Main Results:

• Successfully achieved in-line separation and structural identification of multiple additives in transmission fluids.
• Identified several alkylated diphenylamines, a significant class of antioxidant additives.
• Demonstrated the power of the hyphenated SFC-NMR-MS technique for complex mixture analysis.

Conclusions:

• The hyphenated SFC-NMR-MS technique provides a powerful and efficient method for identifying lubricant additives.
• Alkylated diphenylamines were confirmed as key antioxidant components in the analyzed transmission fluids.
• This analytical approach advances the understanding and quality control of lubricant formulations.