Use of o-phthaldialdehyde to chemically reduce the newly generated amino termini responsible for the progressively increasing background during an extended amino acid sequence analysis in a liquid phase sequencer has been described. The results have been compared with Fluram blocking using apomyoglobin and rabbit C-reactive protein as standard and unknown samples, respectively.
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http://dx.doi.org/10.1016/0003-2697(83)90179-3 | DOI Listing |
Environ Sci Technol
September 2021
Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States.
One-electron reductants (OER) photoproduced by chromophoric dissolved organic matter (CDOM) have been shown to be likely precursors for the formation of superoxide and subsequently hydrogen peroxide. An improved method that employs a nitroxide radical probe (3AP) has been developed and utilized to determine the photoproduction rates of OER from a diverse set of CDOM samples. 3AP reacts with OER to produce the hydroxylamine, which is then derivatized with fluorescamine and quantified spectrofluorometrically.
View Article and Find Full Text PDFInt J Pharm
June 2021
Department of Chemical Engineering, Universidad de Alcalá, 28805 Alcalá de Henares, Madrid, Spain.
The antimicrobial lysozyme (Lys) was electrostatically incorporated to negatively charged crosslinked poly(glycidyl methacrylate) (c-PGMA) macromolecular assemblies. The resulting material was characterized by AFM, infrared spectra, water contact angle measurements and the staining with the primary amino specific dye fluorescamine. c-PGMA nanoparticles were successfully loaded with Lys reaching ratios of 27.
View Article and Find Full Text PDFJ Food Drug Anal
January 2019
Faculty of Pharmacy, Department of Pharmaceutical Analytical Chemistry, University of Alexandria - El-Messalah, Alexandria 2152, Egypt.
High performance liquid chromatographic (HPLC) method with a pre-column derivatization based on Hantzsch condensation reaction was applied for simultaneous determination of alendronate sodium (ALN) and its main related impurity, 4-Aminobutanoic acid (ABA) at its pharmacopeial limit. The separation of colored condensation products of ALN and ABA were achieved on Agilent Zobrax Eclipse SB-C18 analytical column (250 × 4.6 mm, 5 μm) using a mobile phase composed of acetonitrile-0.
View Article and Find Full Text PDFEnviron Sci Technol
October 2016
Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20740, United States.
A molecular probe, 3-amino-2,2,5,5,-tetramethy-1-pyrrolydinyloxy (3ap), was employed to determine the formation rates of one-electron reducing intermediates generated photochemically from both untreated and borohydride-reduced Suwanee River fulvic and humic acids (SRFA and SRHA, respectively). This stable nitroxyl radical reacts rapidly with reducing radicals and other one-electron reductants to produce a relatively stable product, the hydroxylamine, which can be derivatized with fluorescamine, separated by HPLC and quantified fluorimetrically. We provide evidence that O and 3ap compete for the same pool(s) of photoproduced reducing intermediates, and that under appropriate experimental conditions, the initial rate of hydroxylamine formation (R) can provide an estimate of the initial rate of superoxide (O) formation.
View Article and Find Full Text PDFTalanta
June 2014
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005, China. Electronic address:
A simple and rapid fluorescence method has been developed for the determination of acrylamide in heat-processed food samples. In the determination, acrylamide is degraded through Hofmann reaction to generate vinyl amine, and pyrrolinone is produced when the vinyl amine reacts with fluorescamine, resulting in a strong fluorescence emission at 480 nm. Hofmann reaction is a key step for the fluorescence determination of acrylaminde, and the reaction conditions are investigated and optimized.
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