A novel Cu–BSA nanocomposite based vapour generation approach for the rapid determination of mercury in aqueous media by cold vapour atomic absorption spectrometry and on-line flow injection inductively coupled plasma mass spectrometry

The present study reports, for the first time, novel Copper–Bovine Serum Albumin nanocomposites (Cu–BSA NCs) based vapor generation as a simple, rapid and reliable approach for the sensitive determination of mercury in water. Copper nanoparticles in the form of Cu–BSA NCs acted as reductant to convert mercury ions to elemental mercury (Hg0) which was subsequently quantified using cold vapour atomic absorption spectrometry (CVAAS) and on-line flow injection inductively coupled plasma mass spectrometry (FI-ICPMS). The basic experimental parameters such as reaction time, amount of copper nanoparticles, pH and temperature of sample solution related to chemical vapour generation (CVG), have been optimized for both inorganic mercury (iHg) and methyl mercury (MeHg) species using CVAAS in batch mode. These studies indicate that the reduction process is very rapid (<20 s) when the pH and temperature of the sample solution is maintained at ≥4.0 and ∼90 °C, respectively. After optimizing the conditions by CVAAS, further studies were performed with on-line FI-ICPMS. The recoveries of mercury species were found to be in the range of 97–104%. The absolute limits of detection of the developed method in conjunction with FI-ICPMS were 2.8 pg and 4.1 pg for iHg and MeHg, respectively. Interference of concomitant ions and possible mechanism of the Cu–BSA NCs induced vapor generation of mercury have been discussed in detail. The proposed CVG method was applied to the analysis of total mercury in various natural water samples.