Determination of divalent trace metals in a soil sample using electrospray ionization mass spectrometry

A novel pre-separation technique for the determination of divalent trace heavy metals in a soil sample was developed, in which deferoxamine was used as a masking agent for trivalent metal ions, Al3+ and Fe3+, and a chelate column was applied to collect target heavy metal ions and to eliminate alkali metal and alkaline earth metal ions. Deferoxamine had such a strong and selective masking effect on Al3+ and Fe3+ that divalent trace heavy metals in the soil sample were well separated from considerably greater amounts of Al3+ and Fe3+. Consequently, the determination of four trace metals (Ni, Cu, Zn, and Pb) in a certified soil reference material (JSAC-0401) was successfully performed using electrospray ionization mass spectrometry (ESIMS).