UV-DSC Principle
Ultraviolet-visible spectrophotometry is an analytical method for measuring the absorption spectrum of substance molecules in the ultraviolet region. Ultraviolet absorption spectra are formed when valence electrons of a substance transition from low-energy to high-energy levels after absorbing ultraviolet light, generating absorption peaks. Not all organic substances absorb in the ultraviolet region—only compounds with conjugated double bonds (π bonds) have π electrons easily excited for transitions, forming characteristic absorption peaks in the ultraviolet region.
Equipment Model and Parameters
- Instrument Model: Shimadzu UV2700
- Technical Parameters:
- Optical system: Double-beam
- Spectrometer: Double monochromator, aberration-corrected Czerny-Turner device
- Wavelength setting range: 185–1400 nm
- Testing wavelength range: 185–1100 nm (PMT replacement required)
- Diffraction grating groove density: 1300 lines/mm
- Wavelength accuracy: ±0.1 nm (at 656.1 nm); ±0.3 nm (full band)
- Wavelength repeatability: ±0.05 nm
Sample Submission Requirements
- Volume: >10 mL of substances with ultraviolet absorption properties (solid, liquid, or powdered solutions at specific concentrations).
- Samples must be non-volatile and non-toxic.
Application Fields
Applied in characterization of synthetic intermediates, natural products, pharmaceutical raw materials, metal-organic complexes, synthetic rubbers, and polymer materials, including:
- Testing functional groups of compounds
- Identifying chemical properties
- Comparing differences between formulations or products
Testing Examples
Reference Standards
- ISO 7887:2011 "Water quality — Determination of color by ultraviolet-visible spectroscopy"
- ISO 705:2020 "Plastics — Determination of ultraviolet stability (UV-Vis transmittance method)"
- ASTM E958-13(2021) "Standard Test Method for Spectral Bandwidth of Ultraviolet-Visible Spectrometers"
- USP <857> "Ultraviolet-Visible Spectrophotometry in Pharmaceutical Analysis"
- GB/T 11894-2021 "Water quality — Determination of total nitrogen — Alkaline potassium persulfate digestion ultraviolet spectrophotometry"
- GB 5009.268-2016 "National Food Safety Standard — Determination of multiple elements in foods (UV-Vis method for partial elements)"
