Dear Colleagues. if any one works to detect variations in the isotopic composition of Zn using the Double spike technique, then please just let us have more discussion about it. Variation in the isotopic composition of Zn is too small(<1 per mil) and it is too difficult to detect due to interferences accompanied with the measurements. the main interference is the interference in the 67 isotope of Zn. Thanks Sam Ghidan Ghidan O.Y. Ph.D Student Room Nu:301.001 Dept of Applied Physics Curtin University of Technology GPO Box:U1987 Perth - WA 6845 Australia Phone number: (61) 8 9266 2336 Home: (61) 8 9258 4028 --------------------------------- TV dinner still cooling? Check out "Tonight's Picks" on Yahoo! TV.