Standard and Sample Preparation
One common approach to calibrating the instrument for
analysis of biodiesel is to dilute organometallic standards in
a solvent such as kerosene. The standards are commercially
available as organometallics in petroleum base oil. While
not a major issue, these diluted oil standards do not have
the same physical properties as biodiesel. The use of an
internal standard can generally compensate for the physical
differences but since biodiesel standards are now available
(VHG Labs, Inc.), matrix matching is now much easier and
the preparation of calibration standards is much simpler. The
samples and calibration standards are simply diluted in the
solvent prior to analysis and there are minimal corrections
required of the internal standard.