In keeping with the tradition of this highly successful and respected series, Volume 70 contains 31 procedures, carefully checked and edited by independent laboratories. For the first time, procedures are accompanied by a new section on waste disposal data. This includes any special disposal of chemical waste utilized by the submitters in order to comply with modern, clean disposal practices of toxic materials. This monograph should be consulted by all users of these volumes, in keeping with current trends to preserve the environment.