Microwave-Assisted Digestion of Polyurethane Foam as an Alternative to Elution: Solid Phase Extraction of Cd(II) and Pb(II) for Their Determination in Swimming Pool Waters

In this work, a separation/preconcentration method is proposed for the determination of Cd(II) and Pb(II) in swimming pool waters, using ammonium pyrrolidine dithiocarbamate (APDC) as a complexing agent and unloaded polyurethane foam (PUF) as a sorbent. The proposed method was optimized, and the defined optimal conditions were a pH of 7, 30 min of shaking time, 400 mg of PUF, and 0.5% (m/v) of the APDC solution. The release of Cd(II) and Pb(II) from the solid phase was achieved through the total digestion of PUF using a microwave-assisted acid approach with a 10.5 mol center dot L-1 HNO3 solution. The methodology was applied to four samples of swimming pool water for the determination of Cd(II) and Pb(II) using graphite furnace atomic absorption spectrometry (GF AAS). The limits of detection and quantification obtained were 0.02 and 0.06 mu g center dot L-1 for Cd(II) and 0.5 e 1.8 mu g center dot L-1 for Pb(II), respectively. We analyzed four samples of swimming pool waters, finding Cd concentrations between 0.22 and 1.37 mu g center dot L-1. On the other hand, only one sample presented Pb concentration above the limit of quantification (11.4 mu g center dot L-1). Recovery tests were performed by spiking the samples with known concentrations of the analytes, and recovery percentages between 82% and 105% were obtained.

Automated summary

A separation/preconcentration method using APDC as a complexing agent and PUF as a sorbent was proposed for determining Cd(II) and Pb(II) in swimming pool waters. Optimal conditions were determined, and Cd(II) and Pb(II) were released from the solid phase using a microwave-assisted acid approach. The method was applied to swimming pool water samples, and the limits of detection and quantification were determined.