Matrix-assisted laser synthetic polymers

Two relatively new techniques, matrix assisted laser desorption ionization-lime of flight mass spectrometry (MALDI-TOF) and electrospray ionization (FS1), offer new possibilities for analysis of polymers with molecular weights in the tens of thousands. PS molecular weights as high as 1.5 million have been determined by MALDI-TOF. Recent reviews on the application of these techniques to synthetic polymers include those by Ilantoif54 and Nielen.555 The methods have been much used to provide evidence for initiation and termination mechanisms in various forms of living and controlled radical polymerization.550 Some examples of the application of MALDI-TOF and ESI in end group determination are provided in Table 3.12. The table is not intended to be a comprehensive survey. 

Matrix-assisted laser desorption ionisation (MALDI) MH+ (M - H) ToF, IT, FTMS Polar and some nonpolar biopolymers, synthetic polymers >250000... 

Even if relatively new, HF FIFFF has been used to separate supramicrometer particles, proteins, water-soluble polymers, and synthetic organic-soluble polymers. Particle separation in HF FIFFF has recently been improved, reaching the level of efficiency normally achieved by conventional, rectangular FIFFF channels. With these channel-optimized HF FIFFF systems, separation speed and the resolution of nanosized particles have been increased. HF FIFFF has recently been examined as a means for off-line and on-line protein characterization by using the mass spectrometry (MS) through matrix-assisted laser desorption ionization time-of-flight mass spectrometry (M ALDl-TOF MS) and electrospray ionization (ESl)-TOF MS, as specific detectors. On-line HF FIFFF and ESl-TOF MS analysis has demonstrated the viability of fractionating proteins by HF FIFFF followed by direct analysis of the protein ions in MS [38]. 

Following the first studies of J.J. Thomson (1912), mass spectrometry has undergone countless improvements. Since 1958, gas chromatography coupled with mass spectrometry has revolutionized the analysis of volatile compounds. Another revolution occurred in the 1980s when the technique became available for the study of non-volatile compounds such as peptides, oligosaccharides, phospholipids, bile salts, etc. From the discoveries of electrospray and matrix-assisted laser desorption in the late 1980s, compounds with molecular masses exceeding several hundred thousands of daltons, such as synthetic polymers, proteins, gly-cans and polynucleotides, have been analysed by mass spectrometry. 

Matrix-assisted laser desorption ionization (MALDI), like ESI, is capable of ionizing and launching very large molecules (e.g, polysaccharides, synthetic polymers, peptides, and proteins) into the gas phase and is a major analytical tool for high-throughput proteomic studies.17,53 In many respects, MALDI is a complementary technique to ESI and both techniques are often applied to the same sample when determining protein identity. ESI produces macromolecular ions from solution, whereas MALDI produces them from the solid state. 

Matrix assisted laser desorption ionisation (MALDI) is an important technique for characterisation and fingerprinting of large molecules. However, solvents used at sample preparation have a negative effect on the quahty of the fingerprint. Work is therefore performed on development of solvent free sample preparation methods for characterisation of synthetic polymers [61]. 

During the last decade, processing of polymers has become an important field of applied and fundamental research [48]. One of the most important fields is laser ablation involving various techniques and applications. Laser ablation is used as an analytical tool for MALDI (matrix-assisted laser de-sorption/ionization) [28, 29] and LIBS (laser-induced breakdown spectroscopy) [49] or as a preparative tool for PLD (pulsed laser deposition) of inorganic materials [37] and of synthetic polymer films [50, 51]. Another application is surface modification of polymers [52] if low fluences are applied, the polymer surface can be either chemically modified to improve adhesion... 

Since its discovery, laser polymer processing has become an important field of applied and fundamental research. The research can be separated into two fields, the investigation of the ablation mechanism and its modeling and the application of laser ablation to produce novel materials. Laser ablation is used as an analytical tool in matrix-assisted laser desorption/ionization (MALDI) [12,13] and laser-induced breakdown spectroscopy (LIBS) [14] or as preparative tool for pulsed laser deposition (PLD) of synthetic polymers [15,16] and of inorganic films [17,18],... 

Wetzel, S.J., Guttman, C.M. and Flynn, K.M., The influence of electrospray deposition in matrix-assisted laser desorption/ionization mass spectrometry sample preparation for synthetic polymers. Rapid Commun Mass Spectrom, 18 (2004) 1139-1146. 

The techniques of matrix-assisted laser desorption/ ionization-time of flight (MALDI-TOF) and electro-spray/ionization (ESI) have revolutionized biological MS since 1989. All state-of-the-art biochemistry and biology laboratories possess at least one of these ionization techniques and, in general, have access to both of them. Both ionization techniques are applicable to peptides and proteins, DNA and RNA, glycoconjugates, and synthetic polymers. 

Jackson, A. T., Yates, H. T., Scrivens, J. H., Critchley, G., Brown, J., Green, M. R., and Bateman, R. H., The application of matrix-assisted laser desorption/ioniza-tion combined with collision-induced dissociation in the analysis of synthetic polymers. Rapid Commun. Mass Spectrom., 10, 1668, 1996. 

Bahr, U., Deppe, A., Karas, M., Hillenkamp, R, and Giessman, U., Mass Spectrometry of Synthetic Polymers by UV-Matrix-Assisted Laser Desorption/ Ionization, Anal. Ghent., 64, 2866,1992. 

Cottrell, J. S., Koemer, M., and Gerhards, R., The Characterization of Synthetic Polymers by Matrix-assisted Laser Desorption/Ionization Mass Spectrometry Rapid Gontm. Mass. Spectrom., 9, 1662, 1995. 

Macha, S. F., Limbach, P. A., and Savickas, P. J., Application of Nonpolar Matrices for the Analysis of Low Molecular Weight Nonpolar Synthetic Polymers by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry, /. Am. Soc. Mass Spectrom., 11, 731, 2000. 

Danis, P. O. and Karr, D. E., A Facile Sample Preparation for the Analysis of Synthetic Organic Polymers by Matrix-assisted Laser Desorption/Ionization, Org. Mass Spec. 28, 923, 1993. 

Lloyd, P. M., Scrivener, E., Maloney, D. R., Haddleton, D. M., and Derrick, P. J., Cation Attachment to Synthetic Polymers in Matrix-Assisted Laser Desorption/ Ionization Mass Spectrometry, Polymer Preprint, 847, 1996. 

King, R. C., Goldschmidt, R., Xiong, Y., and Owens, K. G., Mechanistic Studies of the Cationization of Synthetic Polymers by Alkaly Metals in the Matrix-assisted Laser Desorption/Ionization Experiment. 43rd ASMS Conf. Mass Spectrom., Atlanta, GA, 1237, 1995. 

Nielen, M. W. and Malucha, S., Characterization of Polydisperse Synthetic Polymers by Size-exclusion Chromatography/Matrix-assisted Laser Desorption/ Ionization Time-of-flight Mass Spectrometry, Rapid Comm. Mass Spectrom., 11, 1194, 1997. 

Pasch, H. and Gores, R, Matrix-assisted Laser Desorption/Ionization Mass Spectrometry of Synthetic Polymers 2. Analysis of Poly(methyl methacrylate). Polymer, 36, 1999, 1995. 

Matrix assisted laser desorption ionization-time of flight mass spectroscopy (MALDI-TOF MS) has proven to be a powerful tool for analysis of many biopolymers, such as proteins, oligonucleotides, and polysaccharides. Recently, it has been used to characterize many synthetic polymers [174]. Another... 

Matrix-assisted laser desorption ionization is a very powerful technique for the analysis of synthetics and biopolymers, and it has completely replaced former techniques such as fast atom bombardment (FAB). In most cases, singly charged ions are predominantly detected while very little fragmentation or multiply charged ions are observed. MALDI is commonly used for the analysis of high-molecular-weight compounds such as peptides and proteins (Rappsilber et al., 2003), synthetic polymers (Nielen, 1999), deoxyribonucleic acid (DNA) (Gut, 2004), and lipids (Schiller et al., 2004). 

Danis, P.O. and Karr, D.E. (1993) A facile sample preparation for the analysis of synthetic organic polymers by matrix-assisted laser desorption/ ionization. Org. Mass Spectrom., 28, 923-925. 

Macha, S.F., Umbach, P.A., and Savickas, P.J. (2000) Application of nonpolar matrices for the analysis of low molecular weight nonpolar synthetic polymers by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. J. Am. Soc. Mass Spectrom., 11, 7i -7i7. 

G. (1998) Time-delayed extraction matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry of polyacrylonitrile and other synthetic polymers with the matrix 4-hydroxybenzylidene malononitrile. Rapid Common. Mass Spectrom., 12, 1344-1350. 

Brandt, H., Ehmann, T., and Otto, M. (2010) Solvent selection for matrix-assisted laser desorption/ionization time-of-flight mass spectrometric analysis of synthetic polymers employing solubility parameters. 

Lloyd, P.M., Suddaby, K.G., Varney, J.E., Scrivener, E., Derrick, P.J., and Haddleton, D.M. (1995) A comparison between matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and size exclusion chromatography in the mass characterization of synthetic polymers with narrow molecular-mass distributions poly(methyl methacrylate) and poly (styrene). Eur. Mass Spectrom.,... 

Meier, M.A.R. and Schubert, U.S. (2003) Evaluation of a new multiple-layer spotting technique for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of synthetic polymers. Rapid Commun. Mass Spectrom., 17, 713-715. 

---