Determination of Trace Lead in Seawater Using Isotope Dilution by Inductively Coupled Plasma Mass Spectrometry (ICP-MS)

The chelating reaction of lead with 8-hydroquinoline-5-sulfonic acid (8-HQS) is used for measuring trace lead in seawater. The detection limits of this method estimated with 3σ of the procedure blank is 0.204 μg/L. The recovery of spiked Pb standard in seawater is 97.9%. The relative standard deviation(s r) is ±0.98%. The certification reference water (GBW 08607) is used to assess the accuracy of this method. The result is in good agreement with the certified value and the recovery is 101%. The parameters of the hyphenated technique, such as the concentration of 8-HQS, sample loading time and speed, washing time, eluent acid concentration and instrumental parameters of MFI-ICP-MS are optimized. This method can be recommended to determine the trace lead concentration in high salt matrix of samples.