Ion chromatography determination of heavy metals in airborne particulate with preconcentration and large volume direct injection

A flow injection analysis system with on-line enrichment was developed for simultaneous determination of trace levels of Cu2+, Ni2+, Zn2+, Co2+, Mn2+, Cd2+, Pb2+ and Fe3+, by high-performance ion chromatography (HPIC) with spectrophotometric detection. It is a highly sensitive and low cost alternative methodology. Ion Pac CS5A was used as the analytical column with eluent composition of sodium nitrate 160 mM and oxalic acid 36 mM. Quantification after post-column reaction with PAR allows detection limits between 0.5 and 5.0 ppb to be attained. The total analysis time is less than 30 min. The proposed procedure was compared with a large volume direct injection method using loop volumes up to 5 mL. Both procedures were applied to the analysis of heavy metals in the PM10 fraction of atmospheric particulate samples. Airborne pollutants such as nickel and cobalt can be quantified in 24 h samples of particulate matter at concentrations of a few ng m(-3).