Synthesis, Characterization and Applications of Phosphinic Acid Extraction Resin

Synthesis, Characterization and Applications of Phosphinic Acid Extraction Resin
　　A novel resin containing alkyl phosphinic acid functional group has been synthesized through chloromethylation and phosphorylation reaction on styrene-divinylbenzene copolymer beads. The synthesized resin was characterized by FT-IR, 31P-NMR and elemental analysis. Some absorption parameters of lanthanides on the resin was measured by bath method.The alkyl phosphinic acid resin (APAR) has been used as a stationary phase to separate 14 lanthanide elements by normal pressure liquid chromatography. The separation of 7 light lanthanide elements has been achieved by high performance liquid chromatography withα-hydroxyl isobutyric acid as a mobile phase.
　　The APAR was also used for on-line preconcentration Magnetic lifter of trace rare earth elements (14 lanthanides and yttrium) and then determined by inductively coupled plasma mass spectrometry. REEs in seawater could be on-line concentrated on the APAR packed column (4.6 i.d.×50 mm in length), and eluted from the column with 0.5 mL 0.1 mol L-1 nitric acid within 30 s. An enrichment factor of nearly 400 was achieved for all REEs when the seawater sample volume was 200 mL, while the matrix and coexisting spectrally interfering ions such as barium, tin and antimony could be simultaneously separated. The detection limits of this proposed method for REEs were in the range from 1.43 pg L-1 of holmium to 12.7 pg L-1 of lanthanum. The recoveries of REEs were higher than 97.9%, and the precision of the relative standard deviation (R.S.D., n = 6) was less than 5%. This method has been successfully applied to the determination of soluble REEs in seawater.Vapor generation atomic fluorescence spectrometry (VG-AFS) coupled with online preconcentration on short column packed with the APAR was also developed for the determination of trace cadmium (Cd) in seawater. During the http://www.999magnet.com/ online preconcentration process, Cd in seawater was concentrated on the column while the matrix of seawater was separated flowing out of the column. Cd concentrated on the column was then eluted effectively from the column with 0.1 mol L-1 tartaric acid. When the sample volume was 200 mL, an enrichment factor 189 was achieved. The detection limit of this proposed method for Cd is 2.67 ng L-1. The recovery of Cd is 96.6% obtained by spiking the correspondence standard, and the precision (RSD) is 4.34%.