Trace element contamination in soil:

In order to determine toxic contaminants in soil samples, the representative samples are collected from surface of the soil, and also at a few depths. These are then passed through a sieve to make it uniform sample and is stored in separate containers to avoid cross contamination. In sequence to determine all the contaminants, the sample is prepared by treating a weighed amount of soil with 1:1 nitric acid and making appropriate solution. Metal contents like as Ni, Cd, Zn, Cu, Pb, etc. are then determined through using appropriate hollow cathode lamp and air-acetylene flame. It is essential that the standard solutions for each element are prepared in appropriate concentration range and their respective calibration plots are obtained.