紫外-可见分光光度法（UV-vis spectrophotometry）.docVIP

紫外-可见分光光度法（UV-vis spectrophotometry） Appendix IV A UV visible spectrophotometry Calibration and verification of instruments Because of the influence of environmental factors on the mechanical part of the 1. wavelength, the wavelength of the instrument often varies slightly The instrument shall be regularly checked and corrected, and the measured wavelength shall be corrected before the determination. Commonly used in mercury lamp Strong spectral lines 237.83nm, 253.65nm, 275.28nm, 296.73nm, 313.16nm, 334.15nm, 365.02nm, 404.66nm, 435.83nm, 546.07nm and 576.96nm; or 486.02nm with deuterium lamp in instrument 656.10nm spectra are corrected; Holmium glass at wavelengths 279.4nm, 287.5nm, 333.7nm, 360.9nm, 418.5nm, 460.0nm, 484.5nm, 536.2nm and 637.5nm have sharp absorption peaks, and can also be wavelength corrected Yes, but because of different sources or as time goes by, there will be minor changes The double beam instrument was corrected with holmium perchlorate solution, and 4% holmium trioxide (Ho2O3) was prepared with 10% perchloric acid as solvent For the solution, the absorption peak wavelength of the solution is 241.13nm, 278.10nm, 287.18nm, 333.44nm, 345.47nm, 361.31nm, 416.28nm, 451.30nm, 485.29nm, 536.64nm, and 640.52nm. The allowable error of instrument wavelength is: ultraviolet + 1nm, 500nm + 2nm, 700nm + 4.8nm. 2. the accuracy of absorbance can be determined by sulfuric acid solution of potassium dichromate. At a temperature of 120 DEG C to a constant weight Potassium dichromate, about 60mg, is accurately formulated and dissolved in 0.005mol/L sulfuric acid solution and diluted to 1000ml, as specified in the regulations The absorption coefficient is measured and calculated at the wavelength and compared with the prescribed absorption coefficient, which shall be in accordance with the provisions of the table. Wavelength /nm 235 (minimum) 257 (maximum) 313 (minimum) 350 (maximum) Absorption coefficient (1%) 1cmE) the specified values are 124.5, 144, 48.6,