1. A method to quantify biomarkers, comprising providing a sample comprising a biomarker, the biomarker comprising one or more chemicals that are related to a physiological condition; preparing the sample for X-ray analysis by exposing the sample to a solution; using an X-ray fluorescence spectrometer to perform an X-ray fluorescence analysis on the sample to obtain spectral features derived from the biomarker; and quantifying the X-ray fluorescence signal of the biomarker; wherein the X-ray fluorescence spectrometer irradiates the sample with polychromatic X-rays.