Dear all, If I evaporate a 10 ml 6N HCl at temperature of 60oC down to a small drop of about 0.2 ml. Is this drop still 6N HCl or it changes (>>6N or <<6N). Any hydrogen isotope fractionation between this small drop and the original acid? How about with a 6N HNO3? Many thanks for your comments. Shao-Yong ***************************************** Dr. Shao-Yong Jiang Max-Planck-Institut fuer Chemie Abt. Geochemie Postfach 3060 D-55020 Mainz Germany fax: 49 - 6131 - 371051 phone: 49 - 6131 - 305261 email: [log in to unmask] *****************************************