PRELIMINARY-RESULTS ON THE USE OF RUTHERFORD FORWARD SCATTERING FOR THE ELEMENTAL ANALYSIS OF LIQUID ORGANIC-SAMPLES

A new method proposed for the elemental analysis of liquid organic sam ples has been used in this pilot investigation to determine the concen tration of several non-volatile light elements contained in human amni otic fluid (AF) from a single measurement. The technique is based on R utherford forward scattering (RFS) at 28 degrees of a 16 MeV Li-7 beam from vacuum dried AF samples deposited on a formvar support. The risk of contamination of the AF sample due to its manipulation is minimum since it is not required to treat the sample chemically. Statistically significant yields were obtained for beam currents of 5 nA and irradi ation periods of 30 min approximately. An energy calibration with the spectrum obtained from the irradiation of an AF target was carried out to take into account any effect due to the AF organic matrix. AF spec tra were quantified by a chi square fitting of Gaussian curves to elem ent signals. According to this study, the RFS method may be considered as a potential method for light trace element analysis of non-volatil e fractions where standard techniques such as PIXE/PIGE and TXRF are d ifficult to apply. (C) 1998 Published by Elsevier Science B.V.