| Lead has three major valence species, i.e., Pb(Ⅳ), Pb(Ⅲ) and Pb(Ⅱ), in the environment. The species of Pb(Ⅳ) and Pb(Ⅲ) are easily transformed into Pb(Ⅱ), Pb(Ⅱ) is the very common species among the lead compounds. In general, the high valence state lead is more toxic than the low valence one. Lead is harmful to people, animal and aquatic plants. The lead pollution has been a critical issue along with the development of modern industry. Therefore, establishment of a sensitive and reliable method to detect lead, especially for that in water environment is required.In this dissertation, a new method by combining the injection off-line solid phase extraction and pre-concentration procedure with graphite furnace atomic absorption spectrophotometry (GFAAS) was established to detect the lead in water. A poly (ionic liquid) was synthesized by polymerization of the ionic liquid monomer1-(acryloyloxy) propyl-3-methyl imidazolium hexafluorophosphate. The poly (ionic liquid) was immobilized on the surface of the silicon oxide as the lead absorbent.In a off-line injection system, dis (diphenythiocarbazone) lead was adsorbed on the immobilized poly (ionic liquid) by passing the Pb(Ⅱ) sample solution through the pretreatment column. The adsorbed Pb(Ⅱ) was eluted from the column by using2.0mol l-1HNO3solution. The recovered Pb(Ⅱ) in the eluant was quantified by use of a GFAAS. Under the optimal experimental conditions, an adsorption efficiency of ca.91%was obtained to Pb(Ⅱ).The proposed method was used to determine a certified reference lead of reverine water (GBW08608) and good agreement was achieved. The proposed method was also demonstrated by determination of lead in practical snow samples. |
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