Glycol (HS-GC)

OELCHECK test instrument: Perkin Elmer Clarus 580 with Turbo Matrix HS-40 Modul
Sample quantity: ca. 0.5 ml
Unit: ppm
Test result: Glycol content
Result range: 50 - 1000 ppm
Analysis for: engine oils, motor vehicle gear oils
Brief description:

Before the ethylenglycol in engine oils can be analysed with gas chromatography (GC) a derivatisation reagent which reacts with the ethylenglycol is added. The sample is heated afterwards and all volatile components are transferred into the GC with a headspace injection. They reach a column which holds the analytes back with varying durations. One after the other the analytes are rinsed off the column and detected afterwards. The identification of the ethylenglycol is based on the retention time.

The concentration is calculated by a comparison of the peak area with prior detected calibration standards of which concentration is known.

Statement: With the headspace gas chromatography it is possible to detect a small amount of coolant in engine and gear oils with high precision. With the determined glycol content it is easy to see if an internal combustion engine has a defect at the cylinder head gasket or a coolant got into the gear through leaks.
Underlying test standard: ASTM D7922