The o-phthalaldehyde derivatives of amines for high-speed liquid chromatography/electrochemistry

Allison, Laura A.; Mayer, Ginny S.; Shoup, Ronald E.

doi:10.1021/ac00271a010

Cited by 232 publications

(70 citation statements)

References 29 publications

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“…Free amino acids were extracted, derivatized, separated, and quantitated by high performance liquid chromatography. [28][29][30] The linearity of the detector response was checked with pure standards of each measured amino acid. Lipids were extracted from tissue specimens.…”

Section: Methodsmentioning

confidence: 99%

Hypoglycemia prevents increase in lactic acidosis during reperfusion after temporary cerebral ischemia in rats

et al. 1995

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Sequential 31 P and 1 H MRS was used to measure cerebral phosphate metabolites, intracellular pH, and lactate in normoglycemic and hypoglycemic rats during 30 min of complete cerebral ischemia and 5.5 h of reperfusion. These results were correlated with brain levels of free fatty acids (FFAs), excitatory amino acids, cations, and water content at death. The lactate/N-acetyl aspartate ratio was not significantly different between groups before or during occlusion. During reperfusion, the ratio was higher in normoglycemic rats from 3 to 85 min (p≤ 0.05), and recovery time was faster in hypoglycemic rats (29 vs 45 min; p = 0.04), suggesting reduced lactate production and faster recovery of aerobic metabolism. During occlusion, significant but comparable decrease of intracellular pH occurred in each group. Intracellular pH was higher in hypoglycemic rats at 140 min and 260 min of reperfusion. Water content, Na and K + concentrations, and FFA and excitatory amino acid levels were not significantly different between groups, but hypoglycemic rats had less depletion of levels of Mg 2+ (p=0.011). These results show that hypoglycemia has a limited but potentially beneficial effect on postischemic lactic acidosis.

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Section: Methodsmentioning

confidence: 99%

Hypoglycemia prevents increase in lactic acidosis during reperfusion after temporary cerebral ischemia in rats

et al. 1995

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“…This is presumably a result of secondary reactions between the reagents and the derivative and intramolecular reactions causing breakdown of the isoindole product Numerous authors have discussed these effects in the formation of OPA-thiol-amine isoindoles (Nakamura et al, 1982;Stobaugh et al, 1983;Allison et al, 1984;Jacobs et al, 1986) and the major loss is attributed to the reaction of excess OPA with the isoindole. "IRe stability of iso-…”

Section: Derivatization Chemistrymentioning

confidence: 99%

Low-level atmospheric sulfur dioxide measurement using HPLC/fluorescence detection

1993

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Abstract. An automated technique for measuring SO2 in ambient air has been developed. Air is passed through a gas/liquid exchange coil with an aqueous absorber solution containing 10 ~tM formaldehyde and 0.84 mM Na:EDTA. The SOz rapidly equilibrates with bisulfite (HSO~) and sulfite (SO~-) in the aqueous solution. The aqueous S(IV) is subsequently reacted with o-phthalaldehyde in the presence of excess ethanolamine to form a fluorescent isoindole in a continuous flow stream. This derivative is then separated using reversed phase HPLC and detected via fluorescence with excitation and emission wavelengths at 330 and 380 nm, respectively. The lower limit of detection is 7 pptv (S/N = 3), with a measurement period of eight minutes per sample. The instrument response is linear over several orders of magnitude.

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“…Any derivatization should be fast, based on commercially available reagents, and applicable to minor or even trace components. Owing to increased resolution and sensitivity, pre-column derivatization is more favorable than post-column reaction (Allison et al, 1984). For example, the method by Smolders et al (1995), based on OPA-tert-butylthiol in combination with a microbore column, strongly improves the stability of the derivatives and the sensitivity of the system.…”

Section: Introductionmentioning

confidence: 99%

Chemically enhanced liquid chromatography/tandem mass spectrometry determination of glutamic acid in the diffusion medium of retinal cells

Timperio

Fagioni

Grandinetti

et al. 2007

Biomedical Chromatography

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A rapid, reproducible and highly sensitive method, based on liquid chromatography mass spectrometry, was developed for the determination of the excitatory amino acid glutamic acid released in the diffusion medium of control, ischemic and mutant cells from retinas. Signal intensity of glutamic acid was enhanced by dansyl chloride derivatization giving rise to a detection limit in the order of pmol/mL. Further, in HPLC-ESI-MS detection an MS-friendly dansyl group to glutamic acid enhanced both ionization efficiency in the ESI source and collision-activated dissociation in the collision cell. The sample processing procedure included liquid-liquid extraction, derivatization with dansyl chloride and a final cation-exchange extraction to generate clean extracts for LC/MS/MS analysis. This approach has been validated as sensitive, linear (20-300 ng/mL), accurate and precise for the differential quantification of glutamic acid in the diffusion medium of retina cells. This is the first report of using chemical derivatization to enhance MS/MS detection of the glutamic acid released in the diffusion medium of wild-type and mutant retina cells, under ischemic conditions.

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The o-phthalaldehyde derivatives of amines for high-speed liquid chromatography/electrochemistry

Cited by 232 publications

References 29 publications

Hypoglycemia prevents increase in lactic acidosis during reperfusion after temporary cerebral ischemia in rats

Hypoglycemia prevents increase in lactic acidosis during reperfusion after temporary cerebral ischemia in rats

Low-level atmospheric sulfur dioxide measurement using HPLC/fluorescence detection

Chemically enhanced liquid chromatography/tandem mass spectrometry determination of glutamic acid in the diffusion medium of retinal cells

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