Analysis of three different types of fullerene derivatives by laser desorption/ionization time‐of‐flight mass spectrometry with new matrices

Abstract

Gallbladder bile, one of the most important body fluids, is composed of water, inorganic ions, conjugated bile salts, phospholipids, cholesterol, bilirubin, mucin and proteins. The separation and identification of bile proteins remain difficult due to the complexity of this matrix. In the present study, human gallbladder bile was obtained from a cholesterol stone patient, and the proteins were isolated and purified by dialysis, precipitation and delipidation procedures. The resulting proteins were divided into several aliquots. One aliquot was subjected to two-dimensional gel electrophoresis (2DE). The protein spots were then in-gel digested and analyzed by liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS). Another aliquot was directly digested and analyzed by a combination of strong cation-exchange (SCX) and reversed-phase (RP) chromatography prior to tandem mass spectrometry (2D-LC/MS/MS). Eventually, 48 and 218 unique proteins were identified from 2DE/MS and 2D-LC/MS/MS, respectively, resulting in a total of 222 unique identified proteins. Of the 218 proteins identified by 2D-LC/MS/MS, 92 were identified based on more than one unique tryptic peptide, and, of the total 222 proteins, 98 were identified based on more than one unique tryptic peptide.

Beyond nC60: strategies for identification of transformation products of fullerene oxidation in aquatic and biological samples

“…Nevertheless, less-derivatized fullerenes for example C 60 O have also been detected successfully. Even though past attempts to identify highly hydroxylated fullerene ions were unsuccessful [123, 126], the characteristic m / z 720 ion of the C 60 fullerene peak is a suitable qualitative indicator for successful enrichment of C 60 and its derivatives.…”

Electron capture atmospheric pressure photoionization mass spectrometry: analysis of fullerenes, perfluorinated compounds, and pentafluorobenzyl derivatives

“…However, fragmentation still poses a problem and a trial and error process must be utilized in order to identify appropriate matrices for obtaining the molecular ion signal of each specific fullerene. [13][14][15][16][17][18][19] ESI is not readily amenable to the analysis of fullerenes due to their low polarity. However, as ESI is the softest ionization method, various modifications of this method have been developed for fullerene ionization.…”

Analysis of phytosterol by MALDI-TOF mass spectrometry

“…A higher number of b-sitosterol molecules decreased the M/A ratio; in such cases, the crystal formation of the matrix plus analyte was affected. 54 Conversely, a lower number of b-sitosterol molecules with which to react, results in weak signals. The results of this experiment suggest that the analyte concentration affects the absolute intensity of peaks and the ionization behavior of the analyte.…”

“…Thus, lower signals were observed. A higher number of b-sitosterol molecules decreased the M/A ratio; in such cases, the crystal formation of the matrix plus analyte was affected 54. Conversely, a lower number of b-sitosterol molecules with which to react, results in weak signals.…”