SIMULTANEOUS DETERMINATION OF METAL TRACES BY ICP-MS IN ENVIRONMENTAL WATERS USING SPE PRECONCENTRATION ON DIFFERENT POLYMERIC SORBENTS

abstrakt

angličtina

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 a Helium collision cell during measurement. Monitored interfering elements were K+, Na+, Fe3+, Ca2+, Mg2+, Al3+, HCO3-. For the preconcentration non-polar sorbents based on polymeric sorbents (copolymers of styren-divinylbenzen, especially XAD-16 and XAD-1180) were used. Elements were retained as their chelates with different organic reagents - 4-(2-pyridylazo) resorcinol (PAR) (I), Alizarine S (II), 8-Hydroxyquinoline-5-sulphonic acid (8HQS) (III) and Ammonium pyrrolidinedithiocarbamate (APDC) (IV). 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.

water, ICP-MS, SPE, Amberlite XAD 16, Amberlite SDB-L

HOLUBOVÁ, Z.; SOMMER, L.

17. 8. 2011

0009-2770

Chemické listy

105

18

Česká republika

s973

s974

2