Enantiomer-selective ultraviolet photolysis of temperature-controlled protonated tryptophan (TrpH(+)) on the chiral crown ether, (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid (18C6TA), was examined using a tandem mass spectrometer containing a temperature-variable 22-pole ion trap. The spectra of D-TrpH(+)-(+)-18C6TA at 9-320 K showed that the loss of NH2CH2COOH due to C-alpha-C-beta bond cleavage decreased gradually with increasing temperature. The spectrum at room temperature was similar to that of L-TrpH(+)-(+)-18C6TA, which showed no temperature dependence on photolysis. The chiral-specific photolysis of cold D-TrpH(+)-(+)-18C6TA was attributed to the structures involving the chiral-dependent interactions of the C-alpha-H group of TrpH(+) with the oxygen atoms of (+)-18C6TA. (C) 2014 Elsevier B.V. All rights reserved.