LAUSR

In this work, mesoporous strontium titanate nanoparticles (SrTiO 3 NPs) were synthesized through a single-step combustion process and were characterized by FT-IR, XRD, SEM-EDX, and TEM. The effects of main parameters that may influence the extraction process (i.e., pH, sorbent amount, time of extraction, eluting agent, and the presence concomitant ions) were investigated. The optimum extraction was achieved at pH 6, 50 mg of sorbent, 20-min shaking time, and 4.0 mL of 0.1 mol L −1 thiourea as desorption agent. Under these conditions, the maximum adsorption capacity was 155.6 mg g −1 with a preconcentration factor of 250 (for a 1000 mL sample solution). The calibration graph was linear up to 1000 μg L −1 and the limit of detection was 1.75 μg L −1 . The precision (as relative standard deviation) was 2.53% ( n  = 10). The procedure was employed for the preconcentration of Pb 2+ from blood and urine samples of bladder cancer patients before its determination by FAAS.