STANDARD-FREE METHOD FOR BODY FLUID SAMPLES SUCH AS SALIVA, SWEAT, SNIVAL AND TEAR

We have developed standard-free methods for PIXE analysis of hair, nail, urine and serum, and they have widely been applied to studies on human exposure to some toxic elements caused by pollution in many countries. Although these samples are known to be quite suited for evaluating human exposure to toxic elements, there is a case where it is required to quantitatively analyze other samples taken from people. We have examined sweat, saliva, snivel and tear, which are expected to be useful for estimating concentration of various elements in a human body. However, sufficient quantities of them are difficult to be taken from a human body and it is required to establish standard-free methods for these samples. In the present work, standard-free methods for sweat and saliva were established and its accuracy and reproducibility are confirmed. It becomes possible to quantitatively analyze only a drop of sweat and saliva by means of this method. For snivel and tear, potassium concentration is obtained by the internal-standard method for a small-spot sample and the conversion coefficient required for the standard-free method was evaluated. It is found that analyses of these samples give us useful information about some specific elements. As the standard-free methods are free from dryness of samples, which becomes a serious problem in the case where the internal-standard method is applied, it is expected to give more essential information about elemental concentration in a human body.