Emission Spectroscopy

EMISSION SPECTROSCOPY

INTRODUCTION

Emission spectroscopy is exclusively related to atoms whereas a number of other spectroscopic techniques deal with molecules. The fundamental fact of emission spectroscopy is very simple, wherein the atoms present in a sample undergo excitation due to the absorption of either electrical or thermal energy. Subsequently, the radiation emitted by atoms in an excited sample is studied in an elaborated manner both qualitatively and quantitatively. Therefore, emission spectroscopy is considered to be an useful analytical tool for the analysis of :

(i) elemental analysis of metals,

(ii) identification and quantitative determination of metallic elements,

(iii) estimation of metalloids e.g., arsenic, silicon, selenium, present is extremely low concentrations, and

(iv) analysis of solids, liquids or gases as follows :

solids-as such or evaporated solutions,

liquids-atomized spray, analyzed occasionally, and

gases-analyzed rarely.

In short, emission spectroscopy is considered to be the most accurate, precise and reliable means of quantitative analysis of elements as on date. If proper skill, precautions and wisdom are applied together this method may be adopted safely and conveniently to analyze approximately seventy elements from the ‘periodic table’ at a concentration as low as 1 ppm.