Sample Preparation:

All samples for determination through AAS or AES must be in solution form except for spark source AES whereas solids especially metals and alloys along with smooth surface could be analysed directly. You would recall that in principle, the sample in solid, liquid or in the gas phase could be analysed through flame AAS but in practice the sample is taken in the solution form. The solution of the solids is commonly prepared through wet dissolution method using an appropriate acid. The presence of organic solvents of low molar mass e.g. alcohols, ethers, ketones and esters are found to enhance absorption peaks and therefore increase sensitivity. A microwave digestion system (MDS) offers more rapid and efficient decomposition of complex matrices of geological and biological samples. It greatly decreases the operator time to prepare samples for analysis. More so, it can be simply automated also.

Instead in ICP-AES, the solution preparation depends on the nature of the sample and the concentration of elements to be determined. The solution for ICP analysis could be prepared either through wet acid method or through direct attack method and appropriate precautions are taken as per the requirements of the plasma source.