Direct digestion of human scalp hair on the substrate used for total reflection X-ray fluorescence analysis

It is important to determine the elemental content of scalp hair to evaluate human health and environmental contamination. Here, a new sample preparation method for total reflection X-ray fluorescence analysis was developed by directly digesting the human hair on the sample holder. A human hair sample was subjected to thermal nitric acid treatment for sample digestion and homogenization. The Zn concentration was estimated to be ~ 1.89 × 10² μg/g. We can evaluate other elements of human hair by using this method.