COMBINATION WITH THIN LAYER RESIN SEPARATION BASED ON QUATERNION ASSOCIATION COMPLEX SYSTEM AND SPECTROPHOTOMETRY DETECTION FOR TRACE COBALT

A quaternion association complex system which was formed by HDMG, iodine anion, Co(II) and 717 strong alkalescence anion exchange resin, has the largest absorbance at the wavelength of 450nm. With the quaternion association complex system, the sensitivity was 14 times larger than that of the ternary association complex of HDMG, iodine and Co (II) in water solution, based on the increase of absorbance sectional surface and the p electron free space of the Co complex in the resin phase. This increase also changed the largest absorbance wavelength from 442nm (in water solution) to 454nm (in resin phase). At the pH of the quaternion association complex systems of Zn(II) and Ni(II) were not formed, therefore the disturbance of coexist Zn(II) and Ni (II) would be limited. The RSD of the overall method was 1.3% (n=6) for 2.0g/ml. The developed method was applied in the determination of trace Cobalt in Vitamin B12 and surface water, the linear range of 0.024~2.0g/ml and detection limited of 10.4ng/ml were achieved.