We report on a new approach how to perform UV sample pretreatment of river water samples using solar UV-A radiation. Water samples were collected from River Warnow (Rostock, Germany) and acidified to pH 2 with ultrapure HNO3. Hydrogen peroxide was added to the samples as a photochemical reaction initiator. The samples were transferred to PET bottles and irradiated with solar UV-A (3.6 mW/m2) for at least 6 hours. The concentrations of Zn, Cd, Pb, and Cu were determined by differential pulse anodic stripping-voltammetry (DP-ASV). The comparison of the values with the results obtained for the original untreated sample and the artificial UV treated one proved that solar UV radiation can be applied for the digestion of dissolved organic carbon in trace metal analysis in natural waters like river water, lake waters, well waters etc. [1]. An even larger effect of both UV treatment methods was observed in case of adsorptive stripping voltammetric (AdSV) determination of Ni, Co [2], and U [3]. These analytes could not at all be measured without any UV treatment due to the humic compounds in the river water. Solar UV-A was as effective as artificial 254 nm UV from a 30 W lamp. The approach reported here should be very useful for mobile electrochemical heavy metal analysis in regions where intense sunlight is available. [1] G. Woldemichael, T. Tulu, G.-U. Flechsig, International Journal of Electrochemistry 2011 (2011) article ID 481370. [2] G. Woldemichael, G.-U. Flechsig, Advances in Chemistry 2014 (2014) Article ID 938419. [3] G. Woldemichael, T. Tulu, G.-U. Flechsig, Microchimica Acta 179 (2012) 99.

Solar UV photooxidation as pretreatment for stripping voltammetric trace metal analysis in river water

249th National Meeting (2015)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.