Preparation of a Novel Bi-imprinted Adsorbent for Pb(Ⅱ) and Its Application to FAAS Determination of Trace Amount of Lead in Water Sample

A novel bi-imprinted adsorbent for Pb(Ⅱ) (abbr. as Pb-BIA) was prepared by the molecular imprinting technique using MPS as functional isomer, Pb(Ⅱ)-ion and CTMAB as pattern plates, TEOS (in CH3OH) as sol and NaOH solution as catalyst. Its structural features and surface properties were characterised and studied by FT-IRS and ASAP2010 system. It was shown that in the BIA, Pb(Ⅱ)-pattern plate was removed and functional group of -SH was resumed, and that its surface area and bore diameter were raised by the presence of CTMAB. It was found that under static condition, rate of adsorption of Pb(Ⅱ) by the BIA attained to 95% in 10 min; the maximum adsorption capacity was found to be 545.6 mg·g-1; and the relative selectivity coefficient found was 192 in the presence of Cd(Ⅱ). Rate of desorption of Pb(Ⅱ) from BIA attained to 94.4% when eluted with 5 mL of 0.5 mol·L-1 HNO3 solution. The BIA was used as extractant in SPE for separation and enrichment of traces of Pb(Ⅱ) in an enviromental water sample, and Pb(Ⅱ) was eluted from the column, and determined by FAAS. Values of recovery were found in the range of 104% to 106%.