UTILITY OF MATRIX-ASSISTED LASER-DESORPTION IONIZATION TIME-OF-FLIGHT MASS-SPECTROMETRY FOR THE ANALYSIS OF LOW-MOLECULAR-WEIGHT COMPOUNDS

A range of low molecular weight compounds (<800 Da) have been examined by matrix-assisted laser desorption time-of-flight mass spectrometry to demonstrate the general analytical utility of this technique. The compound classes investigated included: carbohydrates, quaternary ammonium salts, sterols, nucleosides, purine and pyrimidine bases, amino acids, catecholamines, opioids, antibiotics, prostaglandins and a range of macrocyclic metal complexes of porphyrins and phthalocyanines. Many of the compounds tested are of biochemical, geochemical, industrial and/or therapeutic interest. Most organic analytes gave intense protonated molecules, but some were characterized by sodium adduct ions (i.e., [M + Na](+)). The metal-containing compounds formed radical-cation molecular ions. In all instances the ions detected could be assigned, and excellent agreements between calculated and experimental mass values were obtained.