Application of the TXRF method to the elemental analysis of cerebrospinal fluid in amyotrophic lateral sclerosis

The total reflection x‐ray fluorescence technique was applied to the determination of the elemental composition of cerebrospinal fluid (CSF) in the neurodegenerative disease amyotrophic lateral sclerosis (ALS). Samples of the CSF from two groups of patients, ALS and control, were analysed. Two methods of sample preparation were tested in order to improve the detection limits of the analysed elements. The elements Cl, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Rb and Rb were found and determined. Differences in the concentrations of Zn and Cl were found between the ALS and the control group.