Spectroscopy is a predominant branch of analytical chemistry that deals with the examine of concentration of analyte as a function of amount of radiation absorbed whilst electromagnetic radiation from suitable source is directed at it. Spectroscopy is additionally defined as a method of evaluation, which includes the measurements of the intensity and wavelength of radiation that is both absorbed or transmitted. What you need to recognize from both definitions is that, whilst electromagnetic radiation passes via a solution of a compound (sample), a positive amount of mild radiation is absorbed with the aid of the molecules. According to Beer’s law, the quantity of radiation absorbed by means of the molecule in solution is proportional to the number of absorbing molecules in the answer (concentration). The absorbed radiation brings about a lower in the depth of the transmitted (unabsorbed) radiation. The greater the variety of absorbing molecules (concentration), the extra is the depth of absorption. Spectroscopic techniques can be used in the willpower of the concentration (quantitative analysis) of an analyte and in the identification (qualitative analysis) of an analyte. The devices used to examine or measure the absorption or emissions of electromagnetic radiation as a function of wavelength are spectrometers and spectrophotometers.