In clinical chemistry it can be very useful to have a rapid method for the determination of trace elements in biological material available. Because the classical wet digestion method which is generally used for the destruction of biological materials requires much attention, two procedures were tried which should be less time consuming or require less attention. The two new procedures which are the soluene (a quaternary ammonium hydroxide) method of Jackson (1) and the method of Adrian (2) utilizing pressure were applied to the determination of Cu and Zn in human brain tissue and in fish meal by atomic absorption spectroscopy