Portable X-ray fluorescence trace metal measurement in organic rich soils: pXRF response as a function of organic matter fraction

Results demonstrate attenuation of the pXRF signal with increasing sample organic matter fraction; however, elementally dependent deviations from expected concentrations were also observed. An empirical organic matter fraction-dependent calibration method was developed and its performance was evaluated using four unmodified soil standards with known organic matter content. Estimates incorporating soil organic matter differed from conventional calibration estimates neglecting organic matter content, yet were able to reproduce standard reference material values with similar success.