Searching for specificity through the design and synthesis of new ionic imprinted polymers (IIP) for isolation and preconcentration purposes in FI-SPE-ETAAS.

ORNELA PIANA; MANUELA KIM; JORGE STRIPEIKIS; MATÍAS JOBBAGY; MABEL TUDINO

MAR DEL PLATA

Simposio; ELEVENTH RIO SYMPOSIUM ON ATOMIC SPECTROMETRY; 2010

RIO SYMPOSIUM ON ATOMIC SPECTROMETRY

In this work, we present the laboratory synthesis of hybrid mesoporous solids with ionic imprinting (IIP) which have been employed for the on-line preconcentration and determination of ultratrace levels of inorganic nickel in water by solid phase extraction (SPE) coupled to electrothermal atomic absorption spectrometry (ETAAS). The solids were designed with the aim of obtaining specificity for the isolation and determination of nickel by means of key-lock interactions between the analyte and the different solids. We have synthetized new organic-inorganic materials based on a hierarchical silica skeleton functionalized with different proportions of 3-aminopropyl-trietoxisilane (APTES) coordinated with Ni(II). We have tested different synthetic routes in order to reach the best exposure of the sequestering groups to the analyte in order to enhance the percentage of extraction. The coefficients of maximum retention of nickel onto the different solids were calculated through batch experiments with the assistance of flame atomic absorption spectrometry. Different physicochemical variables (pH, ionic strength) were evaluated in order to optimize the retention process and thus, to increase the preconcentrated amount of analyte. The same experiments were performed under the dynamic conditions imposed by flow injection (FI) and the best set of operational variables was chosen. The main findings will be fully discussed. Regarding specificity, model solutions carrying the analyte and different amounts of organic compounds and other elemental concomitants were tested. The recovery results will be given and evaluated. Up to now, the efficiency of release has not been improved as several eluents compatible with the electrothermal atomizer operation need to be assayed. However, we will show our first results in comparison to others already reported.