Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
JEOL USA, Inc., 11 Dearborn Road, Peabody, Massachusetts 01960, United States.
Anal Chem. 2020 Jun 2;92(11):7399-7403. doi: 10.1021/acs.analchem.0c01070. Epub 2020 May 21.
Residual acid found in the desorption ionization using through-holes alumina membranes (DIUTHAME) induces a reproducible protonation/in-source dissociation of polymers made of ester, amide, or siloxane moieties during their surface-assisted laser desorption ionization (SALDI) mass analysis. Deposited on the DIUTHAME chips in solution (solvent-based) or in pure form by melting the polymer powder in situ (solvent-free), high-molecular-weight nylons, silicone, or functionalized celluloses among other polymers are instantly fingerprinted by laser DIUTHAME high-resolution mass spectrometry (MS) with specific patterns resembling their direct analysis in real-time (DART) single-stage or tandem mass spectra. Depending on the polymer, two main types of fingerprints are observed with either the protonated monomer or product ions revealing the nature of the repeating unit or its functionalization. This technique allows a rapid molecular analysis of industrial homopolymers regardless of their molecular weight and complementary to DART with simple or no sample preparation and also promisingly applicable for copolymers.
在通过通孔氧化铝膜（DIUTHAME）解吸电离中发现的残留酸，在它们的表面辅助激光解吸电离（SALDI）质谱分析中，诱导由酯、酰胺或硅氧烷部分组成的聚合物产生可重现的质子化/源内解离。通过将聚合物粉末原位熔融（无溶剂）以溶液（基于溶剂）形式或纯形式沉积在 DIUTHAME 芯片上，高分子量尼龙、硅酮或功能化纤维素等聚合物通过激光 DIUTHAME 高分辨率质谱（MS）进行瞬时指纹识别，具有类似于其实时直接分析（DART）单级或串联质谱的特定图案。根据聚合物的不同，观察到两种主要类型的指纹，要么是质子化单体，要么是产物离子，揭示了重复单元的性质或其官能化。该技术允许快速分析工业均聚物的分子，而与分子量无关，与 DART 互补，无需或只需简单的样品制备，并且有望适用于共聚物。
