Matrix separation and preconcentration of rare earth elements from seawater by poly hydroxamic acid cartridge followed by determination using ICP-MS

The determination of rare earth elements in seawater is a challenge due to high salt content of seawater and extremely low concentrations of rare earth elements. Therefore separation of matrix and preconcentration of rare earth elements is necessary for their detection by inductively coupled plasma mass spectrometer. Polyhydroxamic acid is a potential chelating resin for separation and preconcentration of many elements. In the present work polyhydroxamic acid synthesized from acryl amide as monomer and N, N′- methylene bis acryl amide as cross linker was used in a self fabricated glass cartridge for the preconcentration of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu simultaneously from seawater. Polyhydroxamic acid was found to have good selectivity for rare earth elements with respect to alkali and alkaline earth metals. Therefore major matrix elements such as Na, K and Mg were separated in a single stage with the achievement of a preconcentration factor of 100 for rare earth elements. The uptake of rare earth elements by PHA was > 95% in a wide pH range of 3–7. The limit of detection as calculated by taking synthetic seawater was between 0.08 to 0.44 ng L− 1.

► Separation of the high salt matrix for determination of rare earth elements in seawater is achieved.
► A polyhydroxamic acid (PHA) resin synthesized in house is used for matrix separation.
► The rare earth elements were sorbed selectively on the resin.
► PHA is found to have high capacity for rare earth elements and the sorption process is also very fast.
► A PHA cartridge is developed for separation and preconcentration of rare earth elements.