BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//www.bayceer.uni-bayreuth.de//NONSGML kigkonsult.se iCalcreator 2.41.92//
CALSCALE:GREGORIAN
METHOD:PUBLISH
UID:37363261-3365-4462-b632-326339646630
X-WR-CALNAME:BayCMS-Export
X-WR-CALDESC:This is a calendar exported from BayCMS
X-WR-TIMEZONE:Europe/Berlin
BEGIN:VTIMEZONE
TZID:Europe/Berlin
TZUNTIL:20101031T010000Z
BEGIN:STANDARD
TZNAME:CET
DTSTART:20071028T030000
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
RDATE:20081026T030000
RDATE:20091025T030000
END:STANDARD
BEGIN:DAYLIGHT
TZNAME:CEST
DTSTART:20080330T020000
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
RDATE:20090329T020000
RDATE:20100328T020000
END:DAYLIGHT
END:VTIMEZONE
BEGIN:VEVENT
UID:www.bayceer.uni-bayreuth.de-bayceer-t62438id
DTSTAMP:20260820T044412Z
DESCRIPTION:Eingeladen vom Kolloquiums-Team.The introduction of hydride gen
 eration in the mid 1970s enabled a first look at what lies beyond “total a
 rsenic” concentrations in environmental samples - arsenite was identified 
 to predominate under reducing\, arsenate under oxidizing conditions\; nume
 rous organic arsenic species were later detected by chromatographic separa
 tion and retention time comparison to known standards. This presentation w
 ill show how information from different modern spectroscopic techniques ca
 n be combined to identify and quantify previously unknown species that are
  lost or co-determined during routine species preservation and analysis. I
 n samples from arsenic-sulfidic environments\, anion exchange chromatograp
 hy inductively-coupled plasma-mass spectrometry (AEC-ICP-MS) showed the fo
 rmation of four compounds containing both arsenic and sulfur in significan
 t amounts (up to 80% of total arsenic) and the S:As ratios were quantified
  as 1:1\, 2:1\, 3:1\, and 4:1. Using electrospray ionization mass spectrom
 etry and time-of-flight mass spectrometry (ESI-MS\, ESI-TOF-MS) we were ab
 le to determine the molecular masses of these As-S-compounds\, identify th
 em as thioarsenates (AsSxO4-x3-) and distinguish apparently identical mole
 cular masses of e.g. arsenate (H2AsO4-\, m/z 141) and monothioarsenite (H2
 AsSO2-\, m/z 141) by high-resolution mass-detection and characteristic fra
 ctionation patterns. Previous identification of arsenic-sulfur compounds a
 s thioarsenites based on data from the currently most advanced X-ray absor
 ption spectroscopic methods (XANES and EXAFS) are likely misinterpreted be
 cause absorption edges of thioarsenates are significantly different from t
 hat of arsenate but coincide with that of arsenite and can thus be misiden
 tified as As(III)-species. A brief introduction to the principle of each s
 pectroscopic method will be given for non-users. 
DTSTART;TZID=Europe/Berlin:20081023T170000
DTEND;TZID=Europe/Berlin:20081023T235959
LOCATION:H6
SUMMARY:Prof Dr. Britta Planer-Friedrich\, Umweltgeochemie\, Universität Ba
 yreuth: Using modern spectroscopic techniques to advance trace element spe
 ciation - case study thioarsenic species
TRANSP:TRANSPARENT
END:VEVENT
END:VCALENDAR