Читать книгу X-Ray Fluorescence in Biological Sciences - Группа авторов - Страница 77

Arsenate and arsenite are the two arsenic compounds which are carcinogenic in nature and tend to deposit on human hair, nail, bone, skin, etc. As such, the toxic effects of As are usually observed in those parts of the body.

Analyzing those organs can easily quantify the level of As exposure in that person. But collection of bone, skin, and nail samples from the human body is quite complicated and sometimes becomes impossible compared to scalp hair. More over it was observed that As has a strong tendency to deposit in human scalp hair, as it is composed of keratin, thus hair tissue contains the highest amount of Arsenic compared to other tissues of a suspected patient. At the time of exposure, As combines with hair keratin and becomes trapped in the hair, making it the best sample option for analysis. Nonetheless, hair tissue is a good biological indicator for chronic As exposure as the As excretes slowly through the hair. Therefore, by measuring the concentration of As in scalp hair, it is possible to have an accurate indication of As exposure levels in a body. There are many analytical methods suggested for determining As in scalp hair, but among them EDXRF is the safest and most simple technique, which gives more accurate results as no digestion or chemical treatment is required for sample preparation.