“…The various methods described in the literature include techniques based on the use of classical titration [1,2], mass spectrometry (MALDI-TOF [3][4][5], ESI [6]), various chromatographic techniques [7,8], FTIR [9,10], NMR [11][12][13][14][15][16] and UV [17]. All of the methods described to date suffer from some limitations with respect to sensitivity and/or versatility.…”