Here, I 0 and I denote the emission intensity with and without quenching agent present, k q the rate constant of the quenching process, ? 0 the excited-state lifetime in the absence of quenching agent and [ Q ] the concentration of quenching agent.
12.
Xanthophylls such as zeaxanthin are found in highest quantity in the leaves of most green plants, where they act to modulate light energy and perhaps serve as a non-photochemical quenching agent to deal with triplet chlorophyll ( an excited form of chlorophyll ) which is overproduced at high light levels during photosynthesis.
