Determination of heavy metals in air particulate matter by ion chromatography / Mohd Zahari Abdullah @ Rafie and Rahmalan Ahmad

In recent years, ion chromatography has been increasingly used for the separation and determination of heavy metals. In this study, the separation of Cu2+ Ni2+, Zn2+ and Pb2+ in airborne particuIate sampIes was achieved by the use a complexing eluent containing 20 mM oxalic acid and 20 mM citric acid adjusted to pH 3.6 with lithium hydroxide. Upon elution, the separated metal ions were reacted with PAR (4-(2-pyridylazo) resorcinol to form coloured complexes in a postcolumn reactor and detected by using a UV-Vis detector at 520 nm. Detection limits for a 25-ul sample solution were 2.2, 0.9, 6.6 and 1.8 ug/l for respectively metals. The technique was optimized and validated by analysing the NIST standard reference materials SRM 1648 Urban Particulate Matter and SRM 1633b Coal Fly Ash.