Mass spectra of copolymers

Abstract

Recent and older literature (covering the last 12-13 years) in the field of mass spectra of random and block copolymers is reviewed. A detailed description is given of the information on copolymer properties that can be recovered from the analysis of the low-mass region of the spectrum (the region below 500 Da) and the high-mass region. The features of mass spectra of copolymers obtained by different synthetic routes are discussed, such as free radical, condensation, ring-chain equilibration, microbial synthesis, ring-opening, simple anionic, cationic, Ziegler-Natta, and/or metallocene catalysis, along with some random and block copolymers that occur in Nature. The emphasis is on copolymer composition and average molar mass determination, and on the benefits of coupling mass spectrometry (MS) with separation techniques such as size-exclusion chromatography (SEC) and high performance liquid chromatography (HPLC).

Tandem mass spectrometry of poly(methacrylic acid) oligomers produced by negative mode electrospray ionization

“…A single MS spectrum can allow the nature of the repeat unit and of the end-groups to be confirmed, or copolymers to be distinguished from homopolymers [7]. As MS allows individual co-oligomer ions to be measured, the overall composition can be determined as long as any peak overlap can efficiently be resolved [8].…”

UV-Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis of synthetic polymers by using nor-harmane as matrix

“…Low-soluble and nonsoluble polymers are generally not analyzable by UV-MALDI although the successful use of DMSO in the analysis of chiral polyhydroxy polyamides and the details for the sample preparation method has been described. 20 Nor-harmane has been shown to be a good UV-MALDI matrix for the analysis of a wide variety of non-commercial synthetic polymers [19][20][21][22][23][24][25] and bio-macromolecules, 6,9,12,13,16,17 In the present study commercially available synthetic polymers such as PEG, PMMA, PS and poly(dimethyl)siloxane (PDMS) have been selected for UV-MALDI analysis with nor-harmane. These experiments have been conducted in positive and negative ion modes and the efficiency of the desorption/ionization processes, with and without ionizing salt, have been compared.…”

“…Matrix-assisted ultraviolet laser desorption/ionization time-of-flight mass spectrometry (UV-MALDI-TOF MS) [1][2][3] has become a versatile and important tool for the determination of molecular masses of macromolecules such as synthetic polymers [4][5][6] and bio-polymers. [7][8][9] The principal of UV-MALDI involves ionizing macromolecules for TOF-MS analysis by diluting them in a suitable matrix of small organic molecules which absorb UV-laser photons.…”

“…Thus, carboxylic acids (trans-3-indolacrylic acid (IAA), 2,5-dihydroxybenzoic acid or gentisic acid (GA), sinapinic acid (SA), 2-(4-hydroxyphenylazo)-benzoic acid (HABA), and 5-chlorosalicylic acid), phenols (dithranol), neutral compounds (2-nitrophenyl octyl ether, 1,4-di(2-5-phenyl-oxazolyl)benzene, and all-trans-retinal) and soft basic compounds (carbostyril 124) together with some metals have been employed. 1,5,6,35,36 Even today, the successful characterization of synthetic polymers by UV-MALDI-MS is strongly dependent firstly on the chemical structure of the polymer and secondly on experimental and instrumental factors. It is important to point our that not all synthetic polymers are easily analyzed and polymers with different chemical structures may require different sample handling for a successful analysis.…”

“…Sample preparation for the first three classes of polymers is faily well established. 5,6,34,35 Nonsoluble polymers includes polymers soluble in solvents that are not compatible with known matrix materials. Thus, these are the most difficult to analyze by UV-MALDI because a homogeneous mixture of matrix and analyte that promotes polymermatrix interaction is not easy prepared, or just because the solvent required is not recommended in MALDI technique (i.e., DMSO).…”