Ž . Spectrochimica Acta Part B 55 2000 339353 On-line UV-photooxidation with peroxodisulfate for automated flow injection and for high-performance liquid chromatography coupled to hydride generation atomic absorption spectrometry Dimiter L. Tsalev 1 , Michael Sperling, Bernhard Welz  ¨ Department of Applied Research, Bodenseewerk PerkinElmer GmbH, D-88662, Uberlingen, Germany Received 19 November 1999; accepted 19 January 2000 Abstract An automated on-line UV photooxidation with peroxodisulfate of some environmentally relevant organoarsenic and organotin compounds in a system built from commercially available modules has been studied and optimised with a view to both species-independent quantification of the total arsenic or tin in samples containing different Ž . organic species by flow injection hydride generation atomic absorption spectrometry FI  HGAAS and speciation Ž . analysis by coupled high-performance liquid chromatography HPLC with HGAAS detection. For organoarsenicals, the reaction with alkaline peroxodisulfate in a 10  15-m knotted reactor for 1.5 min insures 90% transformation Ž . of inorganic As III and six organoarsenic species to arsenate: monomethylarsonate, dimethylarsinate, arsenobetaine, arsenocholine, trimethylarsine oxide and tetramethylarsonium. For organotins, the UV photooxidation with acidic peroxodisulfate at 95  100°C provides recoveries of 80% for the inorganic tin, dimethyltin, trimethyltin, triethyltin, tripropyltin, triphenyltin, monobutyltin, dibutyltin and tributyltin but only approximately 15% for tetrabutyltin. The Ž . Ž . best characteristic masses in integrated absorbance A and peak-height A measurements, respectively, are 30 int p Ž . Ž . pg and 480 pg for arsenic V and 22 pg and 410 pg for tin IV , employing 100-l injections. The RSDs are 5.5% and Ž . Ž . 8.5% at 5 ng As V levels and 4.3% and 6.4% at 10 ng Sn IV levels in A and A modes, respectively. The limits of int p Ž . 1 1 detection LOD, 3 for As are 7 gl and 4 gl in FI-UV HGAAS and HPLC UV HGAAS, respectively.  Corresponding author. Current address: Departamento de Quımica, Universidade Federal de Santa Catarina, 88040-900 Flori- ´ anopolis, S.C., Brazil. Fax: 55-48-331-9711. Ž . E-mail address: welz@qmc.ufsc.br B. Welz 1 On leave from Faculty of Chemistry, University of Sofia, Sofia 1126, Bulgaria. 0584-854700$ - see front matter  2000 Elsevier Science B.V. All rights reserved. Ž . PII: S 0 5 8 4 - 8 5 4 7 00 00154-3