scholarly journals Reduction of aflatoxin B1 during tortilla production and identification of degradation by-products by direct-injection electrospray mass spectrometry

2015 ◽  
Vol 57 (1) ◽  
pp. 50 ◽  
Author(s):  
Abigail Moreno-Pedraza ◽  
Laura Valdés-Santiago ◽  
Laura Josefina Hernández-Valadez ◽  
Alicia Rodríguez-Sixtos Higuera ◽  
Robert Winkler ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Aflatoxin B1 ◽  
Room Temperature ◽  
Electrospray Mass Spectrometry ◽  
Direct Injection ◽  
Alkaline Ph ◽  
Principal Factors ◽  
Mass Spectometry ◽  
Kinetics Of ◽  
By Products

Objective. To determine the effect of pH, and exposure time over the inactivation of aflatoxin B1 (AFB1) during the tortilla making process as well as the degradative molecules generated. Materials and methods. Inactivation of AFB1 in maize-dough with alkaline pH and in alkaline methanolic solutions was determined by HPLC. Kinetics of time exposure of AFB1 in methanolic solution and the degradative products were analyzed by direct injection electrospray mass spectometry (DIESI-MS). Results. The alkaline pH of the maize-dough after nixtamalización between 10.2, and 30-40 minutes of resting at room temperature allows the 100% reduction of AFB1. DIESI-MS analysis of the extracts indicated the presence of two degradation molecules from AFB1.Conclusion. The alkaline pH of maize-dough and resting time are the principal factors involved in diminishing AFB1 levels in tortillas. A procedure to the tortilla making process is proposed, which allows the reduction of remnant AFB1, avoiding the accumulative effect over consumers.

Biodegradability enhancement of refractory pollutants by ozonation: a laboratory investigation on an azo-dyes intermediate

1998 ◽  
Vol 38 (4-5) ◽  
pp. 239-245 ◽  
Author(s):  
A. Lopez ◽  
G. Ricco ◽  
G. Mascolo ◽  
G. Tiravanti ◽  
A. C. Di Pinto ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Organic Carbon ◽  
Laboratory Investigation ◽  
Azo Dyes ◽  
Room Temperature ◽  
Carbonic Acid ◽  
Ozone Treatment ◽  
Alkaline Ph ◽  
Degradation Reactions ◽  
By Products

The effectiveness of ozone treatment for improving the biodegradability of recalcitrant pollutants has been proved by investigating the ozonation reaction of FAST-VIOLET-B (FVB) a bioresistant chemical intermediate of azo-dyes. Laboratory scale experiments have been carried out, at room temperature, by bubbling, for 90 min, ozonated air (9ppmO3/min) into 0.35 1 of an alkaline (pH=11) aqueous solution (50 ppm) of FVB. The experimental results indicate that during the ozonation, even though complete FVB degradation occurs in 10 min, ozone consumption goes on for a further 20 min after which time most degradation reactions are completed. The main ozonation by-products, identified by HPLC, IC, and GC-MS are formaldehyde, acetaldehyde, glyoxal, acetone, acetic-, formic-, oxalic- and carbonic-acid, plus six FVB derivatives scarcely biodegradable. At the end of the ozonation, i.e. after 30 min., the initial values of TOC (35 mgC/l) and COD (103 mgO2/l) are respectively 27 and 25 and correspond to a relative removal of about 23% and 76%. As for FVB solution biodegradability expressed as (BOD5)/(COD) ratio, during the first 10 min its value regularly increases from zero up to a maximum of 0.75 that corresponds to an ozone consumption of 2.4 mg per each mg of organic carbon initially present in the solution.

scholarly journals Mass Spectrometric Analysis of Antibody—Epitope Peptide Complex Dissociation: Theoretical Concept and Practical Procedure of Binding Strength Characterization

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4776
Author(s):  
Bright D. Danquah ◽  
Kwabena F. M. Opuni ◽  
Claudia Roewer ◽  
Cornelia Koy ◽  
Michael O. Glocker
Keyword(s):  
Mass Spectrometry ◽  
Dissociation Constant ◽  
Gas Phase ◽  
Immune Complex ◽  
Room Temperature ◽  
Electrospray Mass Spectrometry ◽  
Small Sample ◽  
Epitope Peptide ◽  
Ligand Complex ◽  
Dissociation Constant Kd

Electrospray mass spectrometry is applied to determine apparent binding energies and quasi equilibrium dissociation constants of immune complex dissociation reactions in the gas phase. Myoglobin, a natural protein-ligand complex, has been used to develop the procedure which starts from determining mean charge states and normalized and averaged ion intensities. The apparent dissociation constant KD m0g#= 3.60 × 10−12 for the gas phase heme dissociation process was calculated from the mass spectrometry data and by subsequent extrapolation to room temperature to mimic collision conditions for neutral and resting myoglobin. Similarly, for RNAse S dissociation at room temperature a KD m0g#= 4.03 × 10−12 was determined. The protocol was tested with two immune complexes consisting of epitope peptides and monoclonal antibodies. For the epitope peptide dissociation reaction of the FLAG peptide from the antiFLAG antibody complex an apparent gas phase dissociation constant KD m0g#= 4.04 × 10−12 was calculated. Likewise, an apparent KD m0g#= 4.58 × 10−12 was calculated for the troponin I epitope peptide—antiTroponin I antibody immune complex dissociation. Electrospray mass spectrometry is a rapid method, which requires small sample amounts for either identification of protein-bound ligands or for determination of the apparent gas phase protein-ligand complex binding strengths.

scholarly journals Functional Genomics via Metabolic Footprinting: Monitoring Metabolite Secretion byEscherichia coliTryptophan Metabolism Mutants Using FT–IR and Direct Injection Electrospray Mass Spectrometry

2003 ◽  
Vol 4 (4) ◽  
pp. 376-391 ◽  
Author(s):  
Naheed N. Kaderbhai ◽  
David I. Broadhurst ◽  
David I. Ellis ◽  
Royston Goodacre ◽  
Douglas B. Kell
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Mass Spectrometry ◽  
Gene Knockout ◽  
Direct Injection ◽  
Bacterial Strains ◽  
Mutant Strains ◽  
Unit Mass Resolution ◽  
Metabolic Footprinting ◽  
Ft Ir ◽  
Type Strains

We sought to test the hypothesis that mutant bacterial strains could be discriminated from each other on the basis of the metabolites they secrete into the medium (their ‘metabolic footprint’), using two methods of ‘global’ metabolite analysis (FT–IR and direct injection electrospray mass spectrometry). The biological system used was based on a published study ofEscherichia colitryptophan mutants that had been analysed and discriminated by Yanofsky and colleagues using transcriptome analysis. Wild-type strains supplemented with tryptophan or analogues could be discriminated from controls using FT–IR of 24 h broths, as could each of the mutant strains in both minimal and supplemented media. Direct injection electrospray mass spectrometry with unit mass resolution could also be used to discriminate the strains from each other, and had the advantage that the discrimination required the use of just two or three masses in each case. These were determined via a genetic algorithm. Both methods are rapid, reagentless, reproducible and cheap, and might beneficially be extended to the analysis of gene knockout libraries.

Evaluating the physiological state of maize (Zea mays L.) plants by direct-injection electrospray mass spectrometry (DIESI-MS)

2012 ◽  
Vol 8 (6) ◽  
pp. 1658 ◽  
Author(s):  
Martín García-Flores ◽  
Sheila Juárez-Colunga ◽  
Josaphat Miguel Montero-Vargas ◽  
Janet Ana Isabel López-Arciniega ◽  
Alicia Chagolla ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Zea Mays ◽  
Electrospray Mass Spectrometry ◽  
Zea Mays L ◽  
Direct Injection ◽  
Physiological State

Determination of residues of propamocarb in wine by liquid chromatography-electrospray mass spectrometry with direct injection

2004 ◽  
Vol 21 (6) ◽  
pp. 572-577 ◽  
Author(s):  
J. C. Taylor ◽  
S. J. Hird ◽  
M. D. Sykes ◽  
J. R. Startin
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Electrospray Mass Spectrometry ◽  
Direct Injection

Folding Kinetics of the S100A11 Protein Dimer Studied by Time-Resolved Electrospray Mass Spectrometry and Pulsed Hydrogen−Deuterium Exchange†

Biochemistry ◽  
2006 ◽  
Vol 45 (9) ◽  
pp. 3005-3013 ◽  
Author(s):  
Jingxi Pan ◽  
Anne C. Rintala-Dempsey ◽  
Yu Li ◽  
Gary S. Shaw ◽  
Lars Konermann
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Mass Spectrometry ◽  
Deuterium Exchange ◽  
Hydrogen Deuterium Exchange ◽  
Folding Kinetics ◽  
Time Resolved ◽  
Protein Dimer ◽  
Hydrogen Deuterium ◽  
Kinetics Of

Subunit Disassembly and Unfolding Kinetics of Hemoglobin Studied by Time-Resolved Electrospray Mass Spectrometry†

Biochemistry ◽  
2004 ◽  
Vol 43 (46) ◽  
pp. 14792-14801 ◽  
Author(s):  
Douglas A. Simmons ◽  
Derek J. Wilson ◽  
Gilles A. Lajoie ◽  
Amanda Doherty-Kirby ◽  
Lars Konermann
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Mass Spectrometry ◽  
Time Resolved ◽  
Unfolding Kinetics ◽  
Kinetics Of

Solvation in Electrospray Mass Spectrometry:  Effects on the Reaction Kinetics of Fragmentation Mediated by Ion-Neutral Complexes

2005 ◽  
Vol 70 (13) ◽  
pp. 5111-5118 ◽  
Author(s):  
Ya-Ping Tu ◽  
Limin He ◽  
William Fitch ◽  
Michelle Lam
Keyword(s):  
Mass Spectrometry ◽  
Reaction Kinetics ◽  
Electrospray Mass Spectrometry ◽  
Kinetics Of

Examples of unwanted variation when characterising dissolved organic matter using direct injection electrospray mass spectrometry and chemometrics

2018 ◽  
Vol 10 (22) ◽  
pp. 2636-2646 ◽  
Author(s):  
N. J. Nielsen ◽  
P. Christensen ◽  
C. Stedmon ◽  
J. H. Christensen
Keyword(s):  
Mass Spectrometry ◽  
Quality Control ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Electrospray Mass Spectrometry ◽  
Direct Injection ◽  
Spectral Characteristics ◽  
Ionization Mass ◽  
Mass Spectral ◽  
Control Samples

We describe a methodology for comparing and contrasting a large number of dissolved organic matter samples based on their electrospray ionization mass spectral characteristics and emphasize the importance of quality control samples to monitor unwanted variation.

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