DETERMINATION OF THE TRACE ELEMENTS IN A MIZUHO ICE CORE SAMPLE BY A COMBINATION OF CONVENTIONAL AND HIGH RESOLUTION INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY

Seventeen elements (Li, Na, Mg, Al, Ca, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, Sr, Ba, Pb and Bi) in an Antarctic ice core at Mizuho Station collected by the Japanese Antarctic Research Expedition were determined by a combination of conventional and high resolution inductively coupled plasma mass spectrometry (ICP-MS). The ice sample was separated into five fractions from surface to inner core by stepwise melting. All the elements determined decreased from the core surface to the inner core by one to four orders of magnitude. The surface contaminations of Li, Cr, Ni, Co, Cu, Ba, Pb and Bi penetrated into the second fraction, while only the surface fraction was contaminated for Na, Mg, Al, V, Mn, Fe, Ca and Sr. Zn kept decreasing to the innermost fraction. Na, Mg and Ca may be originated from sea water, while V, Cr, Mn, Fe, Cu, Zn and Sr may be supplied from the crust. Significant portions of Co and Ni could be of extraterrestrial origin