Chemistry · Spectroscopy and Molecular Analysis

When analyzing the absorption spectra of L-tyrosine, changing the pH from acidic to basic medium causes a specific spectral shift. Consider the following general statements regarding spectrophotometric shifts: Statement A: A change in medium from acidic to basic always decreases the molar absorptivity. Statement B: Shifting of the absorption band to a longer wavelength signifies a shift to lower energy, which is known as a red shift (bathochromic shift). Statement C: Shifting of the absorption band to a shorter wavelength signifies a shift to higher energy, which is known as a blue shift (hypsochromic shift). Statement D: A wavelength shift is mandatory for any change in the intensity of an absorption band. Select the combination containing only the universally correct interpretations.