Open AccessIodine-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry
Author(s) -
Sai Raghuveer Chava
Publication year - 2021
Publication title -
annals of advanced biomedical sciences
Language(s) - English
Resource type - Journals
ISSN - 2641-9459
DOI - 10.23880/aabsc-16000156
Subject(s) - chemistry , desorption , matrix assisted laser desorption/ionization , mass spectrometry , iodine , soft laser desorption , protonation , adsorption , iodide , time of flight mass spectrometry , isoelectric focusing , analytical chemistry (journal) , ionization , chromatography , ion , inorganic chemistry , organic chemistry , enzyme
Adsorption and desorption of iodine-containing α-cyano-4-hydroxycinnamic acid (aCCa) matrix species were studied using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The MALDI-TOF MS method showed that ca. 0.8- 1.4 monolayer (~ 100 ppm) of iodine-containing species was adsorbed at the surface and assisted in desorption and ionization of a protein digest peptides or peptides varying in isoelectric potential. At low laser power, desorption of analytes in protonated and sodiated form was observed but not iodine cluster relative to aCCa without iodine, suggesting a two-electron reduction process to form the protonated pseudo molecular ion, although adsorption on the surface would lead to oxidation of iodide to iodine. The addition of iodine to matrix has been demonstrated to greatly facilitate the MALDI-TOF MS process and is a valuable tool when complex protein mixtures need to be analyzed.