Desorption/ionization model

The Desorption/Ionization model of Pachuta and Cooks (Pachuta and Cooks 1987)... 

Desorption/Ionization model A model describing molecular secondary ion emission... 

Pineda, F. J. Antoine, M. D. Demirev, P A. Feldman, A. B. Jackman, J. Longenecker, M. Lin, J. S. Microorganism identification by matrix-assisted laser/desorption ionization mass spectrometry and model-derived ribosomal protein biomarkers. Anal. Chem. 2003,75,3817-3822. 

Mass spectrometry methods based on soft ionization techniques, 59,61,88,89 matrix-assisted laser desorption ionization/time-of-flight (MALDI-TOF), have been successfully applied for the direct analysis of grape and wine extracts and for monitoring flavonoid reactions in model solution studies. They give access to the molecular weights of the different species present in a fraction or extract and, through fragmentation patterns, provide important information on their constitutive units. Description of the various MS techniques can be found in Chapters 1 and 2. 

In initial work, a total of 17 different ILs were evaluated by the solvation parameter model [8]. Ten of these ILs were comprised of imidazolium or pyrolidinium cations paired with different anions. Many of these compounds represent the traditional class of IL solvents that have been used extensively in organic synthesis reactions or in other analytical uses. The remaining seven ILs consisted of substituted ammonium cations that have proven to be successful analyte matrices in matrix-assisted laser desorption ionization (MALDI) mass spectrometry [11]. 

Knochenmuss, R. (2003). A quantitative model of ultraviolet matrix-assisted laser desorption/ ionization including analyte ion generation. Anal. Chem. 75 2199 -2207. 

Figure 1. Early proposal of a unified model for SIMS and other desorption ionization experiments. Reproduced with permission from Ref. 3. Copyright 1983, Elsevier Science Publishers B.V. (First presented at a conference on ion formation from organic solids, Munster, West Germany, 1981.)...

Snel M, Fuller M (2010) High-spatial resolution matrix-assisted laser desorption ionization imaging analysis of glucosylceramide in spleen sections from a mouse model of gaucher disease. Anal Chem 82(9) 3664-3670. doi 10.1021/ac902939k... 

Enzymatic assays can be applied in the marine environment to provide indirect information on dissolved compounds that are available to fuel bacterial production. Approaches that have been commonly appHed include measuring hydrolytic enzyme activities in seawater and monitoring degradation rates of model compounds. Protein hydrolysis in seawater is rapid as expressed by model protein studies (e.g., Nunn et al., 2003 Pantoja and Lee, 1999). This rapid and selective removal of dissolved proteins explains the relatively minor contribution from proteins to the accumulating DOM reservoir even though proteins are by far the most abundant intracellular biochemical. In an elegant study, Nunn and coworkers (2003) used matrix assisted laser desorption/ionization (MALDI) time of flight (TOP) mass... 

Peptides were sequenced using either an Applied Biosystems Model 470 or 477 or a Hewlett Packard GIOOOA protein sequencer, each equipped with narrow bore RP-HPLC for on-line analysis of the PTH-amino acids. Mass analysis of peptides was performed using matrix-assisted laser desorption/ionization mass spectrometry on a KRATOS MALDl 111 with a-cyano-4 hydroxy-cinnamic acid as the matrix. 

A Potthast, T Rosenau, H Koch, K Fischer. The reaction of phenohc model compounds in the laccase-mediator system (LMS) Investigations by matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Holzforschung 53(2) 175-180, 1999. 

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],... 

In this paper, we have compared two commonly used permethylation methods [4, 5] and have applied them to a model carbohydrate compound. The completeness of the methylation steps was established by matrix-assisted laser desorption/ionization tlme-of-flight mass spectrometry (MALDI-TOF MS). The methylated carbohydrate products were acid-hydrolyzed and converted to methylated partially acelylated aldononitrile derivatives (Me PAANs) for linkage analysis by gas chromatography-mass spectrometry (GC-MS) [11]. 

Berkout, V.D., Kryuchkov, S.I., Doroshenko, V.M. (2007) Modeling of ion processes in atmospheric pressure matrix-assisted laser desorption/ionization. Rapid Commun. Mass Spectrom., 21, 2046. 

Bauer, B.I, Guttman, C.M., Liu, D.W., Blair, W.R. (2002) Tri-a-naphthylbenzene as a crystalline or glassy matrix for matrix-assisted laser desorption/ionization a model system for the study of effects of dispersion of polymer samples at a molecular level Rapid Commun. Mass Spectrom., 16,1192—1198. 

Ruh, H., Sandhoff, R., Meyer, B., Gretz, N., and Hopf, C. 2013. Quantitative characterization of tissue globotetraosylceramides in a rat model of polycystic kidney disease by primadrop sample preparation and indirect high-performance thin layer chromatography-matrix-assisted laser desorption/ionization-time-of flight-mass spectrometry with automated data acquisition. Anal. Chem., 85 6233-6240. 

---