Determination of phenol by UV-1100 ultraviolet spectrophotometry - Master's thesis - Dissertation

Determination of phenol by ultraviolet spectrophotometry

UV Spectrophotometric Determination of Phenol Content: Key words: ultraviolet spectrophotometry; disease meat characteristics; phenol; analysis instrument [experimental purpose] 1. Master UV spectroscopy for qualitative and quantitative analysis The basic principle; 2, learn how to use UV1500 UV-visible spectrophotometer. [Experimental principle] Phenol contains a benzene ring and has three characteristic absorption bands resulting from the π→π* transition. The absorption peak is red shifted due to the substitution of -OH. Thereby the energy of the π* orbit is reduced. Firstly, the UV absorption spectrum data of phenol was found in the literature, and the ratio of phenol to max was calculated according to the ratio of the formula lgA=lgk+lgbc and its corresponding absorbance, and compared with the data examined, and the ratios of max and absorbance were compared. See if it is consistent. [Instruments and reagents] 1, instrument: UV1500 UV spectrophotometer; 2cm quartz absorption cell; 25mL colorimetric tube 10; 10mL, 5mL, 1mL pipette each; 100mL, 250mL beaker each; wash 2 ear balls. Experimental reagent: about 0.0003mol / L phenol aqueous solution; 2, reagent: phenol standard aqueous solution weighed 1.000g phenol, dissolved in deionized water, transferred to a 1000mL volumetric flask, diluted with aqueous solution to the mark, shaken, that is 1g / L phenol standard solution. Pipette 10 mL of 1 g/L phenol into a 100 mL volumetric flask, dilute to the mark with water, and shake well to obtain 100 mg/mL. [Experimental contents and steps] 1. Preparation of standard curve: Take 5 25 mL colorimetric tubes and add 1.0 mL, 2.0 mL, 3.0 mL, 4.0 mL, 5.0 mL phenol (100 mg/L). Dilute to the mark with deionized water and shake well. Using a 1 cm quartz cuvette and deionized water as a reference, the absorbance of each solution was measured at the selected maximum wavelength, and the absorbance was plotted against the concentration to make a working curve. 2. Quantitative determination of the content of the waste water: accurately remove 10 mL of the unknown solution into a 25 mL colorimetric tube, dilute to the mark with deionized water, and shake well. The absorbance was measured under the same conditions, and the concentration of the phenol test solution was found on the working curve according to the absorbance, and the phenol content in the unknown liquid was calculated. [Data record and result analysis] Data record processing and mapping analysis are as follows: the concentration of the sample is c=20.488mg/L×2.5=51.220mg/L Keywords: ultraviolet spectrophotometry; disease meat characteristics; phenol; Instrument