The identification of the components present in crude samples purely by mass spectrometric techniques has been a long-standing problem. Conventionally, components present in a crude sample are isolated and purified by chromatographic methods and then various spectrometric techniques (including mass spectrometric techniques) are adopted for their structure elucidation and physical characterization. This paper gives an example illustrating the characterization of the components present in a crude sample purely by mass spectrometric techniques.A commercially obtained curcumin sample (Assay: 65-70%) was chosen for this purpose. The mass analysis of this sample using time-of-flight reflectron mass spectrometric techniques namely plasma desorption (PD), laser desorption (LD) and electrospray ionization (ESI) gave evidence for the presence of curcuminoids other than curcumin in the sample. The electrospray Fourier transform ionization cyclotron resonance mass spectrometry combined with tandem mass spectrometry (MS/MS) has been adopted successfully to confirm the presence of all curcuminoids in the curcumin sample.

A matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometer has been constructed at the Department of Physics, University of Colombo, Sri Lanka. In this mass spectrometer, a solid sample which contains analyte molecules embedded in a suitable matrix compound in excess is exposed to a UV pulsed nitrogen laser source (λ = 337 nm). The desorbed secondary ions from the sample are mass analyzed using the time-of-flight technique. The first MALDI-TOF mass spectra of two peptides namely [tyr 8 ]-bradykinin (1076.2 u) and porcine N-acetyl renin substrate tetradecapeptide (1801.1 u) with the matrix 2,5 di-hydro benzoic acid (154.1 u) have been obtained. Each peptide produced a MH + peak corresponding to its intact molecular ion with m/q values of 1089 ± 6 and 1794 ± 8 respectively.