Improved analysis of ultra-high molecular mass polystyrenes in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry using DCTB matrix and caesium salts. - Gabriel SJ; Steinhoff RF; Pabst M; Schwarzinger C; Zenobi R; Panne U; Weidner SM (Rapid communications in mass spectrometry : RCM, 2015)