Characterizing Oligomeric Hydroxyl Silicon Oils by MALDI-TOF MS With the Pyridine-Modified Matrix

Xiaoxiao Zhang; Yan Wang; Yiqiu Hu; Cheng Guo; Chenghua Li; Kezhi Jiang

doi:10.3389/fchem.2021.755174

Characterizing Oligomeric Hydroxyl Silicon Oils by MALDI-TOF MS With the Pyridine-Modified Matrix

Front Chem. 2021 Nov 23:9:755174. doi: 10.3389/fchem.2021.755174. eCollection 2021.

Authors

Xiaoxiao Zhang^{1

2}, Yan Wang¹, Yiqiu Hu², Cheng Guo², Chenghua Li¹, Kezhi Jiang¹

Affiliations

¹ College of Material, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, Hangzhou, China.
² Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education), The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.

Abstract

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF) is a powerful technique for analysis of various polymers, but it is still very difficult to characterize silicone oil due to its poor ionization efficiency. In this work, oligomeric hydroxyl silicone oils were successfully characterized by MALDI-TOF, by using pyridine-modified 2,5-dihydroxylbenzoic acid (DHB) as the matrix. Furthermore, the mixed crystal of DHB and hydroxyl silicone oil was analyzed by scanning electron microscopy (SEM) and energy disperse spectroscopy (EDS), and the analytical results verified that modification with pyridine could remarkably improve the solubility of hydroxyl silicone oil in DHB, leading to the enhancement of its ionization efficiency in MALDI. The analysis of the MS spectra of a series of hydroxyl silicone oils indicated that they tended to be ionized by the attachment with Na⁺, and the average molecular weight and the degree of polymerization were measured for several oligomeric hydroxyl silicon oils.

Keywords: MALDI-TOF; crystal structure of matrix; ionization efficiency; pyridine-modified DHB; silicon oil.