The Corona charged aerosol detector (CAD) with standard HPLC can be used for the determination of free glycerin and ions (sodium, sulphate, potassium, magnesium and calcium).
Biodiesel is a renewable fuel produced from the esterification of fatty acids from vegetable oil, animal fats or algae-derived oil.
Irrespective of the source, the oil needs to be purified to remove impurities including free glycerol, mono-, di- and triacylglycerols, and a variety of free ions.
Stringent purification methods are required as 'unwashed' biodiesel can result in damage to fuel pumps and clogging of the engine filters and fuel injectors.
Equally important is the ability to quality control the biodiesel and detect low levels of impurities.
The Corona CAD is a sensitive, mass-based HPLC detector that can meet these analytical requirements.
This detector can analyse other non-volatile and some semi-volatile analytes.
The analyte response is less dependent on chemical structure than other detectors (response does not depend on analyte optical properties as with UV, or the ability to ionise, as with mass spectrometry).
In an ESA Biosciences study, detectable impurities in an aqueous extraction of a purified fatty acid methyl ester solution representative of a sample of biodiesel or B100 include: free glycerin 19ppm, sodium 1.1ppm, and sulphate 2.4ppm.
