ESA Biosciences has released an application note describing the use of the Corona charged aerosol detector (CAD) with normal-phase HPLC for the determination of impurities in biodiesel.
Biodiesel is a renewable fuel produced from the esterification of vegetable and animal fats.
During this base-catalysed process, free glycerol and mono-, di- and triacylglycerols are produced, which are contaminants harmful to combustion systems.
As these impurities are typically present at low levels (0.02 per cent glycerol, 0.240 per cent total glycerides), few analytical techniques apart from gas chromatography have the required level of sensitivity to be effective.
This application note describes the use of the Corona charged aerosol detector (CAD) with normal-phase HPLC for the determination of glycerol, and mono-, di- and tri-acylglycerol impurities in biodiesel without requiring sample derivatisation, internal standards and additional or specialised equipment.
The Corona CAD is a sensitive, mass-based HPLC detector suitable for such 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).
ESA said that this is a simpler method with superior accuracy, precision and sensitivity.
The results are comparable to those obtained by the HT-GC ASTM D6584 method.
