• amino acids;
  • hand-held;
  • portable;
  • solution;
  • ice;
  • outdoor

Selected amino acids (glycine, alanine, and threonine) were analysed in the form of water solutions, mixtures of these amino acids in solution, as well as their respective ices using two hand-held instruments under outdoor and winter mountain conditions. The hand-held instruments featured 785 and 532 nm excitations; the latter being one of the first using this wavelength on the market. The changes to the Raman spectra of the solutions and ices are discussed in relationship to the degree of ambiguity of the detection of the amino acids within the mixtures. The hand-held instruments were able to detect two amino acids out of the three in solution. The results showed that the hand-held instruments provide sufficient quality spectra when analysing ices prepared from the solutions; however, an unambiguous detection of these amino acids within mixtures still remains a challenge. Copyright © 2014 John Wiley & Sons, Ltd.