Rigaku Primini Biofuel WDXRF spectrometer

Rigaku has published an application note describing the quantitative analysis of trace amounts of controlled elements in different base oils, including biodiesel and bioethanol, by wavelength dispersive X-ray fluorescence (WDXRF) spectrometry.

Application note XRF 5032 describes quantitative analysis of trace amounts of phosphorus (P), sulfur (S) and chlorine (Cl) in biofuels using the Rigaku Primini Biofuel WDXRF elemental analyser. The report includes information regarding sample preparation, method calibration and repeatability.

Environmental concerns have led to greater use of non-fossil fuels such as bioethanol and biodiesel. As with conventional fuels, the levels of P, S and Cl in biofuels have been reduced to protect engines and catalysts and prevent air pollution.

In the analysis of biofuels, oxygen levels and carbon/hydrogen ratios affect the analysis results of the target elements. Rigaku’s method corrects this influence by analysing scattering X-rays from samples. The Primini Biofuel WDXRF spectrometer is a benchtop analyser optimised for sub-ppm detection limits of P, S and Cl.

The report describes the performance of the spectrometer using the Lite Matrix Correction method, wherein an additional analysing crystal and detector are added to the spectrometer for measurement of the X-rays. The method requires only standards for elements to be analysed and needs no special standards for correction. By applying the method, accuracy can be improved, even for different oil matrices. The same calibration can be used for both biodiesel and bioethanol.