In chemistry, many branches, approaches, and techniques can be applied to clarify the condition of matters or explain the reaction under specific conditions. Spectrophotometry is one of such methods to be applied for measuring the transmittance and absorption properties of chemical substances. Color is everywhere in the human world, and it is possible to use light that passes through solutions and examine an electromagnetic spectrum in wavelengths (Drbodwin, 2010). Spectrophotometry helps conduct qualitative and quantitative analyses in different samples without direct contact. In a biochemical setting, the Beer-Lambert Law is used to determine the concentration of various compounds like nucleic acids, deoxyribonucleic acids, ribonucleic acids, and proteins. The work of a spectrophotometer is based on this law to calculate the amount of light, its absorption, and concentration. Many academic facilities and scientists rely on spectrophotometry results as a simple technique to measure light and understand how color may behave.
Spectrophotometric analysis plays an important role in chemistry, biology, physics, and other natural sciences to learn how the biomolecule concentration of solutions can be determined. In the middle of the 19th century, the final version of Beerâs law was introduced to prove the relationship between transmittance and absorption of a solution. The law states that the way of how a substance absorbs light is proportional to its sample concentration amount; thus, there is a linear relationship between the elements (Khan Academy, 2010). The Beer-Lambert Law introduces the equation:
A = ÆCL, where A is absorbance, Æ is the molar extinction coefficient, C is the molar concentration, and L is an optical path length (Drbodwin, 2010). The transmittance, in its turn, is the ratio between the light amount passing through and the incident light. The intensity of light depends on two factors â the level of concentration and the level of absorption. Many teachers use the same example to describe spectrophotometry: the beakers of different sizes (which affects the absorption) and different concentration levels. There is a simple rule in this experiment, which proves that lower concentration leads to higher intensity and vice versa. The spectrophotometer consists of two devices: a spectrometer to analyze the wavelength of light and a photometer to detect the number of absorbed photons.
The biochemical context implies the possibility of using spectrophotometers in many areas of science, including pharmacology, the analysis of water conditions, and laboratory work. Spectrophotometry is necessary to demonstrate how non-destructive methods help check the condition of the water, its quality, and clarity. The presence of heavy metals may challenge people who use this water for drinking or cooking, and it is important to validate the purity of the substance. Chemical scientists may use the same method during the production of pharmaceuticals/ Spectrophotometry allows comparing and measuring samples to understand their compounds and reveal mistakes, if any.
In general, spectrophotometry is commonly used in different natural sciences, including chemistry, biology, biochemistry, and physics. When it is necessary to measure chemical substances or determine reactions, spectrophotometers are offered to analyze the intensity of light absorbed after passing a solution with a certain level of chemical substances (concentration). There are many elements that remain invisible to the human eye, and the worth of such methods as spectrophotometry is a chance to learn better the world around and understand the changes that seem to be unreasonable or poorly investigated.
References
Drbodwin. (2010). Colored solutions and Beerâs law [Video]. YouTube. Web.
Khan Academy. (2010). Spectrophotometry introduction/Kinetics/Chemistry/Khan academy[Video]. YouTube. Web.