[Novel ionic liquid as solvent for preconcentration of trace lead in dialysis fluids and its determination by graphite furnace atomic absorption spectrometry].

A novel room temperature ionic liquid 1-butyl-3-trimethylsilylimidazolium hexafluorophosphate was designed and synthesized, and was applied to the preconcentration of ultra trace lead in a relatively large volume of dialysis fluids (such as 1 000 mL or bigger). In the present work, dithizone was employed as chelator to form a neutral lead- dithizone complex, and the ionic liquid 1-butyl-3-trimethylsilylimidazolium hexafluorophosphate was used to displace CCl4 as solvent for liquid/liquid extraction of lead complex. The ionic liquid was collected and the lead (II) was back-extracted into aqueous solution by adding nitric acid solution, and the above solution was directly applied to determine lead in the dialysis fluids by graphite furnace atomic absorption spectrometry. Experiments indicated that the proposed extraction system is superior over other systems in which organic solvent such as CCl4 or classical room temperature ionic liquid1-butyl-3-methylimidazolium hexafluorophosphate was selected as extraction medium, and its extraction efficiency of once extraction and enrichment factor of lead was more than 99% and 200 times, respectively. The preconcentration combined with graphite furnace atomic absorption spectrometry has been applied to the determination of trace lead in dialysis fluid samples with satisfactory results.