Spectroscopy is the study of the interaction between matter and light (electromagnetic radiation) (Crouch & Skoog, 2007). It is often phrased as the light of knowledge (Reusch, 2013). In the past, spectroscopy started by the study of visible light dispersed according to its wavelength by a prism (Anon., n.d.). Now, with the knowledge of light having both wave-like and particle-like characteristics, with given frequency or wavelength of light is associated with radiative energy called photon. Spectroscopy is used in physical and analytical chemistry because atoms and molecules have unique spectra (Anon., n.d.). As a result, these spectra can be used to detect, identify and quantify …show more content…
Ionization is effected by a high energy beam of electrons (Reusch, 2013). When high energy electrons collides with a molecule, one of the molecular electrons will be knocked away, leaving behind a molecular cation (Anon., n.d.). Residual energy from the collision may cause the molecular cation to fragment into neutral pieces and smaller fragment cations (Reusch, 2013). These ions are then sorted and separated by the mass analyzer based on the mass-to-charge ratio (Reusch, 2013). It is achieved by accelerating and focusing the ions in a beam (Reusch, 2013). The ions are detected electronically by electron multiplier and results are displayed as spectra of relative abundance as a function of the mass-to-charge ratio (Anon., n.d.). The sample can be identified by the mass of fragments and the fragmentation pattern (Anon., n.d.). (Sparkman, 2000)
2.3 Mass Spectrum
Mass spectrum will be presented as a vertical bar graph (Anon., n.d.). Each bar represents an ion having specific mass-to-charge ratio (m/z) and the length of the bar indicates the relative abundance of the ion (Anon., n.d.). Most ions formed in a mass spectrometer have a single charge, so m/z is equivalent to mass itself (Reusch, 2013). The peak with the greatest intensity is the base peak. The …show more content…
MS is now in very common use in analytical laboratories that study physical, chemical, or biological properties of a great variety of compounds (Anon., n.d.). For example, protein characterization which helps characterized and sequence proteins.
3.1 Infrared Spectroscopy
Infrared (IR) spectroscopy deals with the infrared region of the electromagnetic spectrum that is light with longer wavelength and lower frequency than visible light (Anon., n.d.). It is used to identify and study chemicals base on the functional groups (Anon., n.d.). The IR spectrum is a graph of infrared light transmittance vs frequency or wavelength in terms of wave number.