SIMULTANEOUS DETERMINATION OF METAL TRACES USING SPE PRECONCENTRATION ON AMBERLITE XAD-7 BY ICP-MS IN ENVIRONMENTAL WATERS AND SAMPLES ECOTOXICOLOGY ASSESSMENT OF WATER SMAPLES AFTER MINING AND PROCESSING OF URANIUM

abstract

English

Direct determination of extremely low concentrations of trace elements by modern spetroscopic methods is often difficult. Limitations are associated not only with insufficient sensitivity of analytical equipments, but especially with matrix interference. For this reason, preconcentration and separation of trace elements from matrix are required. This study has been conducted for the determination of nine trace elements (Be, V, Co, Ni, Y, Cd, Pb, Th and U) by inductively coupled plasma mass spectromentry (ICP-MS) in natural waters and water samples after mining and processing of uranium. An ICP-MS spectrometer Agilent 7500ce, with a plasma generator of 27.12 MHz, power output 1500 W and concentric nebulizer MicroMist with a cooled Scott chamber was used. The nonspectral interferences were eliminated by using a solution of internal standards 6Li for 9Be, 45Sc (51V), 72Ge (59Co, 60Ni, 89Y), 103Rh (111Cd), 209Bi (206Pb, 207Pb, 208Pb, 232Th). The spectral interferences were eliminated by using the Helium collision cell during measurement. Monitored interfering elements were K+, Na+, Fe3+, Ca2+, Mg2+, Al3+, HCO3-. For the preconcentration non-polar sorbent based on polymeric sorbents (copolymers of styren-divinylbenzen, especially XAD-7) was used. Elements were retained as their chelates with different organic reagents - 4-(2-pyridylazo) resorcinol (PAR), Alizarine S, 8-Hydroxyquinoline-5-sulphonic acid (8HQS) and Ammonium pyrrolidinedithiocarbamate (APDC). The sorption process was studied under various conditions. The influence of pH is very important, because of the formation of metal chelates and their interaction with the sorbent. Sorbents were also conditioned with different surfactants: Benzyldimethyltetradecylammonium chloride (Zephyramine), 1-etoxycarbonyl-pentadecyltrimethyl-ammonium bromide (Septonex), Brij 35 or Sodium Dodecylsulphate (SDS). Various elution mixtures were also tested, the best results were obtained for the mixture of acetone and ethanol (1:1) in the presence of 1 moll-1 HCl. The excess of acid and organic solvents were evaporated in Teflon dishes prior to the determination by ICP-MS. The Thamnocephalus platyurus as THAMNOTOXKIT FTM, Daphnia magna as a DAPHTOXKIT FTM and Artemia salina are organisms, which were used for ecotoxicology assessment of water samples after mining and processing of uranium. As representative from fytoplankton was tested Lemna minor.

SPE, water, Amberlite XAD 7, ecotoxicology

HOLUBOVÁ, Z.; SOMMER, L.; LESKOVJANOVÁ, J.

24. 9. 2011