Study on the Enhancement of X-ray Fluorescence Intensity from Trace Elements in Hair Using a Backside Secondary Target

Abstract

The measurement and evaluation of the concentration of essential elements in hair, such as calcium iron and zinc, is known as a method for understanding the intake status of these elements that play an important role in the human diet. Analytical methods such as ICP-AES/MS are usually used for hair analysis but in this experiment we used X-ray fluorescence analysis as a simpler and faster measurement method. Furthermore, by applying the principle of the secondary target method we tried to detect X-ray fluorescence from trace elements in hair. In this experiment, a small amount of hair (0.3 mg) was lined up without gaps between the strands as a sample and 99.5 % pure SeO₂ powder, which served as a secondary target and was wrapped in a polymer film, was placed against the back of the hair. In addition to the usual primary X-rays we examined whether the excitation effect could be enhanced by fluorescent X-rays from the secondary target. As a result, the intensity of Zn Ca, and other elements in the hair was amplified by about 10 %. It was found that this method offers the possibility to detect trace elements (Zn, Ca) in hair with higher intensity nondestructively.