Single-column method of chelation ion chromatography for the analysis of trace metals in complex samples

P.N. Nesterenko, P. Jones

J.Chromatogr. A, v.770(1-2), p.129-135 (1997)

ABSTRACT. A single-column chelation ion chromatog. system for the preconcn. and sepn. of trace transition metals is described. The system includes std. chromatog. equipment with a post-column reagent system based on the reaction with 4-(2-pyridylazo)resorcinol followed by photometric detection at 495 nm. Iminodiacetic acid bonded to 5 mkm SiO2 (Diasorb IDA) was used as a chelating stationary phase. The strong complexing ability in combination with good kinetics of complexation and ion-exchange selectivity of iminodiacetic functional groups allow both preconcn. of Mn, Co, Cd, Zn, Ni and Cu from waters of high salinity and efficient sepn. with the same column. The retention characteristics of alk.-earth and transition metal ions on Diasorb IDA SiO2 (250x4 mm I.D.) column was studied for a variety of eluents including HNO3, maleic, malonic, citric, dipicolinic, picolinic, tartaric and oxalic acids. The influence of ionic strength on retention of metal ions involving high nitrate and chloride concns. was also evaluated. The baseline sepn. of preconcd. metals was achieved using a three-step gradient elution scheme which involved 1st, flushing of the column loaded with the sample with 0.5M KCl-0.5 mM HNO3 for 10 min, followed by 80 mM tartaric acid for 20 min and finally 10 mM picolinic acid for 20 min.

Laboratory of Chromatography