Determination of Total Phenol Content in Water by UV-1200 Ultraviolet Spectrophotometry - Master's thesis - Dissertation

Keywords: ultraviolet spectrophotometry; total phenol; US analytical instrument; UV-1100; UV-1200 Phenol is a toxic compound commonly found in industrial wastewater. If it enters rivers or water sources, it can severely affect water quality and pose health risks. Therefore, determining the phenol content in drinking water is essential for ensuring its safety. This experiment aims to teach students how to use ultraviolet spectrophotometry to measure total phenol in water samples. The principle behind this method lies in the fact that compounds with a benzene ring exhibit strong absorption in the ultraviolet region. Phenol has a characteristic absorption peak at 270 nm. According to Lambert-Beer's Law, the absorbance is directly proportional to the concentration of phenol. By measuring the absorbance at this wavelength, we can determine the total phenol content in the sample. For this experiment, we will use a UV spectrophotometer (such as the UV-1100 or UV-1200 model). We will also prepare a standard phenol solution of 250 mg/L by accurately weighing 0.0250 g of phenol and dissolving it in deionized water. After dilution to 100 mL, the solution is well mixed. The procedure includes: 1. Preparing a series of standard solutions by diluting known volumes of the phenol standard. 2. Measuring the absorption spectrum between 220–350 nm to find the maximum absorption wavelength (λmax). 3. Constructing a calibration curve using the absorbance values at λmax. 4. Analyzing the water sample under the same conditions and calculating the phenol concentration based on the calibration curve. Data analysis involves plotting the absorbance versus wavelength to identify λmax, and then plotting absorbance versus concentration to create the calibration curve. Using the absorbance of the water sample, we can calculate the phenol content in the sample in grams per liter. This method is efficient, accurate, and widely used in environmental and chemical analysis for monitoring water quality.