Copper(I) chloride: a simple salt for enhancement of polystyrene cationization in matrix-assisted laser desorption/ionization mass spectrometry

The possibility of using copper(I) chloride as a doping salt to enhance the cationization of polystyrene in matrix-assisted laser desorption/ionizatio n mass spectrometry (MALDI-MS) was investigated. It was shown that copper(I ) chloride possesses sufficient solubility in tetrahydrofuran. The paramete rs of the MALDI mass spectra of different polystyrene samples, such as the number-average (M-n) and mass-average (M-w) molecular mass values, obtained by copper(I) cationization were compared with those obtained by means of s ilver(I) cationization, and good agreement was found. It was also shown tha t application of copper(I) chloride as a doping salt, and dithranol as a ma trix, ensured good MALDI mass spectra of the sample spots even after storag e for 1 month. Copyright (C) 2001 John Wiley & Sons, Ltd.