Increasing demand for critical minerals such as rare earth elements (REEs), driven by the growth of clean technologies. This has resulted in significant interest in the development of new techniques to accelerate the discovery, extraction, and processing of REEs from more easily extracted lower-grade ore deposits. Energy-dispersive X-ray fluorescence spectroscopy (XRF) is a well-established technique for element identification during mining operations where it is readily deployed as portable, in-situ analysers to provide rapid results with minimal sample preparation. However, the accurate detection of REEs using these portable XRF analysers is hindered by spectral overlaps between the L-shell emission lines of REEs and the satellite peaks of more abundant first-row transition metals. Satellite peaks arise most notably from shake-off (multiple ionisation) and radiative Auger processes which are poorly understood for open shell atoms, meaning they are not adequately accounted for in conventional peak-fitting routines. Thus, in REE-containing deposits where first-row transition metals such as V are more abundant than REEs such as Pr and Nd, accurate XRF analysis of REE concentration is particularly challenging as spectral counts may be attributed to the wrong element. Therefore, an investigation into the shake-off and radiative Auger satellite contribution in transition metal spectra is critical to informing accurate analysis of energy-dispersive XRF spectra and improving the limit of detection (LOD) of REEs. This can be achieved through careful characterisation of the line shape, energy position, and intensity of the first-row transition metal satellite profiles using high-resolution X-ray emission spectroscopy (XES). This work reports on the characterisation of the V spectral profile using a laboratory X-ray emission spectrometer, including progress towards extracting the shake-off and radiative Auger satellite structures, and its potential implications for spectral deconvolution and improved fitting of REEs.