Metal(loid)organic compounds in geothermal gases and waters

Volatile metal(loid)organic species of geogenic and anthropogenic origin ar e analyzed by low temperature gas chromatography coupled on-line with plasm a mass spectrometry (LTGC/ICP MS) with detection limits in the higher pg-ra nge (per m(3) gas). In respect to the determination of aqueous samples, thi s instrumental technique is combined with sample derivatization by the hydr ide generation technique. Volatile species of As, Sb, Sr and I could be det ected in gases over hot springs in British Columbia (Canada). Methylated sp ecies of Hg, Ge, As, Sb and Te were also determined in concentrations in th e ng/kg- to low mu g/kg-range in geothermal waters from Ruapehu, Waimangu, Waiotapu and Tokaanu (North Island, New Zealand); up to 1% of the total dis solved metal(loid)s are found in methylated forms. Volatile metal(loid)orga nic species of geogenic origin are compared with those emanating from anthr opogenic sources (waste and sewage gases, river and harbor sediments). Poss ible formation mechanisms for these compounds are discussed. (C) 1998 Elsev ier Science Ltd. Ail rights reserved.