Separation and determination of lead in human urine and water samples based on thiol functionalized mesoporous silica nanoparticles packed on cartridges by micro column fast micro solid-phase extraction

An efficient method based on thiol functionalized mesoporous silica nanoparticles (HS-MSNPs) was used for extraction of lead ions (PbII) from urine and water samples by packed column micro solid phase extraction (PC-MSPE). By procedure, 15 mg of HS-MSNPs packed in syringe cartridges (SC, 5 mL) with cellulose membrane and pH adjusting at 5.5-6.5.  Then, the lead of urine and water sample was efficiently extracted on HS-MSNPs after pushing the plunger of a syringe. Finally, the Pb (II) was back-extracted with inorganic acid solution and the remained solution determined by electrothermal atomic absorption spectrometry (ET-AAS). By optimization conditions, the enrichment factor, LOD, linear range and RSD% was obtained 24.8, 0.04 μg L-1, 0.12-5.5 μg L-1 and less than 5%, respectively for 5 mL of urine samples. The validation was confirmed by spiking of real samples and using certified reference material (CRM, NIST) in water and urine sample.