Secondary ion emission microanalysis: applications to the study of human skin

Secondary ion emission microanalysis is a new method of physical analysis recently applied in biology. The apparatus required (CAMECA SMI 300) enables pictures to be taken of the distribution of certain elements, with a space resolution of the order of 1 microgram. Concentrations below 1 p.p.m. are perceptible for most elements. The present results are the first obtained for human skin sections. Investigation of the natural elements of normal skin reveals no particular accumulation. Elements foreign to the skin are easy to detect. We show here the distribution in the epidermis of clinical antiseptics applied locally. This method has two advantages compared to X-ray microanalysis. It is more sensitive and allows analysis of even the lightest elements. However, its use in skin penetration studies is limited because it does not permit quantitative analysis and serious interference problems may occur.