Search Results - "Roach, John A.G."

Chromatographic separation and identification of conjugated linoleic acid isomers by Roach, John A.G, Mossoba, Magdi M, Yurawecz, M.Peter, Kramer, John K.G

“…There are 56 possible geometric and positional isomers of conjugated octadecadienoic acids (18:2), better known as conjugated linoleic acid (CLA). Positive…”
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Evaluation and single laboratory validation of an on-line turbulent flow extraction tandem mass spectrometry method for melamine in infant formula by Roach, John A.G., DiBussolo, Joe M., Krynitsky, Alex, Noonan, Gregory O.

“…This report presents the single-laboratory validation of a method for the determination of melamine in dairy-based products using on-line turbulent flow…”
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Analysis of Coffee for the Presence of Acrylamide by LC-MS/MS by Andrzejewski, Denis, Roach, John A. G, Gay, Martha L, Musser, Steven M

“…A variety of popular instant, ground, and brewed coffees were analyzed using a modified liquid chromatography−tandem mass spectrometry (LC-MS/MS) method…”
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Rugged LC-MS/MS Survey Analysis for Acrylamide in Foods by Roach, John A. G, Andrzejewski, Denis, Gay, Martha L, Nortrup, David, Musser, Steven M

“…The described liquid chromatography−tandem mass spectrometry (LC-MS/MS) method for the detection of acrylamide in food entails aqueous room temperature…”
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Silver-ion high-performance liquid chromatographic separation and identification of conjugated linoleic acid isomers by Sehat, N, Yurawecz, M.P, Roach, J.A.G, Mossoba, M.M, Kramer, J.K.G, Ku, Y

“…This is the first report of the application of silverion impregnated high‐performance liquid chromatography (Ag+‐HPLC) to the separation of complex mixtures of…”
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Determination of Usnic Acid in Lichen Toxic to Elk by Liquid Chromatography with Ultraviolet and Tandem Mass Spectrometry Detection by Roach, John A. G, Musser, Steven M, Morehouse, Kim, Woo, Jason Y. J

“…Usnic acid is unambiguously confirmed by tandem mass spectrometry (MS/MS) in tumbleweed shield lichen, Xanthoparmelia chlorochroa. The lichen contains 2% usnic…”
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Distributions of conjugated linoleic acid (CLA) isomers in tissue lipid classes of pigs fed a commercial CLA mixture determined by gas chromatography and silver ion-high-performance liquid chromatography by Kramer, J.K.C, Sehat, N, Dugan, M.E.R, Mossoba, M.M, Yurawecz, M.P, Roach, J.A.G, Eulitz, K, Aalhus, J.L, Schafer, A.L, Ku, Y

“…Pigs were fed a commercial conjugated linoleic acid (CLA) mixture, prepared by alkali isomerization of sunflower oil, at 2% of the basal diet, from 61.5 to 106…”
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Identification of conjugated linoleic acid isomers in cheese by gas chromatography, silver ion high performance liquid chromatography and mass spectral reconstructed ion profiles. Comparison of chromatographic elution sequences by Sehat, N. (U.S. Food and Drug Administration, Washington, DC.), Kramer, J.K.G, Mossoba, M.M, Yurawecz, M.P, Roach, J.A.G, Eulitz, K, Morehouse, K.M, Ku, Y

“…Commercial cheese products were analyzed for their composition and content of conjugated linoleic acid (CLA) isomers. The total lipids were extracted from…”
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Analysis of CLA derivatives by GC/MS by Roach, John A.G.

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Preparation, separation, and confirmation of the eight geometrical cis/trans conjugated linoleic acid isomers 8,10- through 11,13-18:2 by Eulitz, K, Yurawecz, M.P, Sehat, N, Fritsche, J, Roach, J.A.G, Mossoba, M.M, Kramer, J.K.G, Adlof, R.O, Ku, Y

“…Conjugated linoleic acid (CLA) mixtures were isomerized with p‐toluenesulfinic acid or I2 catalyst. The resultant mixtures of the eight cis/trans geometric…”
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Improved separation of conjugated fatty acid methyl esters by silver ion-high-performance liquid chromatography by Sehat, N, Rickert, R, Mossoba, M.M, Kramer, J.K.G, Yurawecz, M.P, Roach, J.A.G, Adlof, R.O, Morehouse, K.M, Fritsche, J, Eulitz, K.D

“…Operating from one to six silver ion‐high‐performance liquid chromatography (Ag+‐HPLC) columns in series progressively improved the resolution of the methyl…”
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A new conjugated linoleic acid isomer, 7 trans, 9 cis-octadecadienoic acid, in cow milk, cheese, beef and human milk and adipose tissue by Yurawecz, M.P. (U.S. Food and Drug Administration, Washington, DC.), Roach, J.A.G, Sehat, N, Mossoba, M.M, Kramer, J.K.G, Fritsche, J, Steinhart, H, Ku, Y

“…The identity of a previously unrecognized conjugated linoleic acid (CLA) isomer, 7 trans, 9 cis‐octadecadienoic acid (18∶2) was confirmed in milk, cheese,…”
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Synthesis and isolation of trans‐7, cis‐9 octadecadienoic acid and other CLA isomers by base conjugation of partially hydrogenated γ‐linolenic acid by Delmonte, Pierluigi, Roach, John A. G., Mossoba, Magdi M., Morehouse, K. M., Lehmann, Lutz, Yurawecz, Martin P.

“…CLA is of considerable interest because of reported potentially beneficial effects in animal studies. CLA, while not yet unambiguously defined, is a mixture of…”
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Gas chromatography—High resolution selected‐ion mass spectrometric identification of trace 21∶0 and 20∶2 fatty acids eluting with conjugated linoleic acid isomers by Roach, John A. G., Yurawecz, Martin P., Kramer, John K. G., Mossoba, Magdi M., Eulitz, Klaus, Ku, Yuoh

“…High‐resolution selected‐ion recording (SIR) of the exact molecular ion mass was used to confirm unambiguously the presence of conjugated linoleic acid (CLA)…”
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Furan fatty acids determined as oxidation products of conjugated octadecadienoic acid by Yurawecz, Martin P., Hood, Jennifer K., Mossoba, Magdi M., Roach, John A. G., Ku, Yuoh

“…The objective of this study was to identify oxidation products of conjugated linoleic acid (CLA), a series of octadecadienoic acids with conjugated double…”
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Hplc detection of patulin in apple juice with GC/MS confirmation of patulin identity by Roach, John A G, Brause, Allan R, Eisele, Thomas A, Rupp, Heidi S

“…The official patulin LC procedure was further examined (AOAC 995.10). Juice or juice concentrate was extracted with ethyl acetate and cleaned up with sodium…”
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Analysis of Cyclic Fatty Acid Monomer 2-Alkenyl-4,4-dimethyloxazoline Derivatives by Gas Chromatography−Matrix Isolation−Fourier Transform Infrared Spectroscopy by Mossoba, Magdi M, Yurawecz, Martin P, Roach, John A. G, McDonald, Richard E, Flickinger, Brent D, Perkins, Edward G

“…Recently, cyclic fatty acid monomers (CFAMs) were isolated from heated flaxseed (linseed) oil and analyzed as methyl ester (ME) derivatives by capillary gas…”
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Analysis of trichothecene mycotoxins in contaminated grains by gas chromatography/matrix isolation/Fourier transform infrared spectroscopy and gas chromatography/mass spectrometry by Mossoba, M.M. (U.S. Food and Drug Administration, Washington, DC.), Adams, S, Roach, J.A.G, Trucksess, M.W

“…Gas chromatography/matrix isolation/Fourier transform infrared (GC/MI/FTIR) spectroscopy and GC/mass spectrometry (MS) were used to confirm the identities of…”
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Elucidation of cyclic fatty acid monomer structures. Cyclic and bicyclic ring sizes and double bond position and configuration by Mossoba, Magdi M., Yurawecz, Martin P., Roach, John A. G., Lin, Hubert S., McDonald, Richard E., Flickinger, Brent D., Perkins, Edward G.

“…Gas chromatography (GC)‐electron ionization mass spectrometry of 2‐alkenyl‐4,4‐dimethyl‐oxazoline derivatives was used to confirm the identities of a complex…”
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Conversion of allylic hydroxy oleate to conjugated linoleic acid and methoxy oleate by acid-catalyzed methylation procedures by Yurawecz, M.P. (U.S. Food and Drug Administration, Washington, DC.), Hood, J.K, Roach, J.A.G, Mossoba, M.M, Daniels, D.H, Ku, Y, Pariza, M.W, Chin, S.F

“…Conjugated linoleic acid (CLA), a term describing a group of conjugated octadecadienoic acids that are both naturally occurring and formed during food…”
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