Method, in particular for determining extremely low concentrations of elements and molecules in sample matrices by using laser beams

摘要

The invention relates to a method for determining extremely low concentrations of trace elements and trace molecules in sample matrices. In the method, the sample material to be analysed is converted in a detection chamber into atomised sample vapour the atoms and molecules of which are excited into highly energetic electronic states in two stages in a resonant, Doppler-free and isotope-selective manner and are ionised by collision by means of continuous, narrow-band laser radiation from semiconductor lasers. In the method, the ions produced cause an increase in current in a diode arrangement located in the detection chamber. This increase is recorded electronically and used to determine the concentration of the atoms and molecules of the analyte. Calibration is performed on the activating element in the diode interior. <IMAGE>