Samples originating from biological sources often contain a complex mixture of inorganic salts, buffers, chaotropic agents, surfactants/detergents, preservatives, and other solubilizing agents. However, the presence of these contaminants virtually ensures the failure of any subsequent analysis of the sample by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Sample cleanup procedures, therefore, must be performed prior to MALDI-MS analysis. This paper reports a probe-surface derivatization method that greatly simplifies this sample preparation process. MALDI probes possessing self-assembled monolayers (SAMs) terminated with ionic functional groups can rapidly extract peptides/proteins via ionic interactions from < or = 1-microL volumes of sample solutions placed directly on their surface. We have found that MALDI probes modified in this manner are a practical solution for analyzing very small volumes of peptide/protein solutions contaminated with high levels of inorganic salts, buffers, detergents, chaotropic agents, and other solubilizing agents.
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http://dx.doi.org/10.1021/ac980210i | DOI Listing |
J Hazard Mater
January 2025
Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India.
Experiments were conducted in controlled laboratory conditions to determine the size-resolved CCN (Cloud Condensation Nuclei) activity of sub micrometer-sized aerosols containing nuclear fission products (CsI and CsOH) and abundant ambient inorganic aerosols ammonium sulphates ((NH)SO), ammonium chloride (NHCl), sodium nitrate (NaNO), and sodium chloride (NaCl). The presence of these atmospheric-relevant compounds internally mixed with fission product compounds has the potential to affect the capacity of ambient particulates of aerosols to absorb water and function as CCN. Once in the atmosphere, the dynamics of airborne radionuclides and subsequently their fate gets affected by dry and wet deposition processes.
View Article and Find Full Text PDFInorg Chem
January 2025
Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Science, 630090 Novosibirsk, Russia.
The photoinduced reaction of [Pt(NO)] with pyridine or its derivatives (L) was found to result in the formation of [PtL](NO) salts in high yield. This transformation was successfully probed for methyl- and carboxyethyl-substituted pyridines, and the corresponding [PtL](NO) salts were isolated and fully characterized using single-crystal X-ray diffraction (SCXRD). Anation of the [Pt(py)] cationic complex with N was studied by H NMR spectroscopy in aqueous and water/dimethyl sulfoxide solutions of [Pt(py)](NO).
View Article and Find Full Text PDFMolecules
January 2025
Department of Inorganic Chemistry and Technology, Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia.
The importance of fluorine and aluminum in all aspects of daily life has led to an enormous increase in human exposure to these elements in their various forms. It is therefore important to understand the routes of exposure and to investigate and understand the potential toxicity. Of particular concern are aluminum-fluoride complexes (AlF), which are able to mimic the natural isostructural phosphate group and influence the activity of numerous essential phosphoryl transferases.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Lung Biology, Department of Experimental Medical Sciences, Lund University, 221 84 Lund, Sweden.
Particulate matter (PM) is a major component of ambient air pollution. PM exposure is linked to numerous adverse health effects, including chronic lung diseases. Air quality guidelines designed to regulate levels of ambient PM are currently based on the mass concentration of different particle sizes, independent of their origin and chemical composition.
View Article and Find Full Text PDFJ Org Chem
January 2025
Key Laboratory of Biomass Green Chemical Conversion of Yunnan Provincial Education Department, Yunnan Key La-boratory of Chiral Functional Substance Research and Application, School of Chemistry & Environment, Yunnan Minzu University, Kunming 650504, P. R. China.
We report a base-promoted, metal-free multicomponent tandem reaction, involving a [4 + 1 + 1] cycloaddition process between -substituted nitroarenes, aldehydes, and ammonium salts. Modifying the substituents on the nitroaromatic compounds effectively provides structurally diverse 2-substituted and 4-alkenylquinazolines with good to excellent yields (77%-90% and quinazoline 51 examples) and high tolerance for various inorganic ammonium salts (13 examples, such as NH·HO, NHCl, and NHHF). A new method for constructing 2,4-substituted quinazoline compounds with high selectivity from simple nitrogen source compounds was developed, and the reaction can be scaled up to a gram scale.
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