Optimisation of the storage of natural freshwaters before organotin speciation

• Published in: Water research (Oxford) Vol. 35; no. 1; pp. 224 - 232
• Main Authors: Bancon-Montigny, Chrystelle, Lespes, Gaëtane, Potin-Gautier, Martine
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 2001; Elsevier Science; IWA Publishing/Elsevier
• Subjects: Analysis methods; Analytical chemistry; Applied sciences; Chemical Sciences; Chromatography, Gas; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental Sciences; Exact sciences and technology; experimental design; France; Fresh Water; freshwater; Hydrogen-Ion Concentration; Kinetics; Models, Theoretical; Natural water pollution; Nitric Acid; Organotin Compounds - isolation & purification; organotins; Pollution; Pollution, environment geology; Polyethylenes; storage; Time Factors; Water Pollutants, Chemical - isolation & purification; Water Purification; Water treatment and pollution; France; experimental design; storage; freshwater; organotins; Sample conservation; Water pollution; Chemical analysis; Tin Organic compounds; Optimization; Surface water
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/S0043-1354(00)00238-4

The speciation of organotin compounds is essential due to the species-dependent toxicity, especially in natural waters. Precautions have to be taken during sampling and storage of waters in order to prevent degradations and losses. Experimental design methodology has been used to study the conditions of stability of organotins after water sampling in rivers. The modelling of results allows the determination of optimal conditions of preservation. After acidification at pH=4 with nitric acid, the storage in polyethylene containers at 4°C in the dark is suitable to preserve the most degradable trisubstituted (butyl-and phenyl-) species over 1 month. These conditions of sampling and storage are applied to two different freshwaters. The rate of species decomposition appears to be only dependent on the water nature, whatever the organotin concentrations in the sample. Speciation could be so preserved between 1 and 3 months.