Yoshimi Kitada

3-Aminobenzamide and 3-aminobenzoic acid, tags for capillary electrophoresis of complex carbohydrates with laser-induced fluorescent detection.

The efficiencies in derivatization of reducing carbohydrates were compared by capillary electrophoresis using maltose as a model with nine monoaminobenzene derivatives by reductive amination in the presence of sodium cyanoborohydride. We found that aminobenzene derivatives substituted at the 3-position showed good reactivity with reducing carbohydrates as expected from the reaction mechanism, although the fluorescence intensities and molar absorptivities of these derivatives were not as high as those of 2- and 4-aminobenzene derivatives. The reagents, 3-aminobenzamide and 3-aminobenzoic acid, which showed the highest reactivity, were applied to the labeling of carbohydrate chains obtained from some sialic acid-containing glycoprotein samples, and also high-mannose and hybrid-type oligosaccharides. Capillary electrophoresis of these labeled carbohydrate chains in an inner surface-modified capillary with (50% phenyl)methylpolysiloxane allowed excellent separation of sialic acid-containing carbohydrate chains derived from fetuin and thyroglobulin as well as high mannose-type and hybrid-type carbohydrates derived from bovine pancreas ribonuclease B, soybean agglutinin and hen ovalbumin. The lower limit of calibration was as low as the 10(-16) mol (injected amount) with helium-cadmium laser induced detection.

Direct analysis of several Fusarium mycotoxins in cereals by capillary gas chromatography–mass spectrometry

A method for qualitative and quantitative analysis of Fusarium mycotoxins by gas chromatography-mass spectrometry (GC-MS) using cold on-column injection was improved. Eight typical mycotoxins, including deoxynivalenol (DON), 3-acetyldeoxynivalenol (3ADN), fusarenon-X (FX), diacetoxyscirpenol (DAS), 15-monoacetylscirpenol (15MAS), T-2 toxin (T-2), scirpentriol (SCT), and zearalenone (ZEA) were subjected to GC-MS without chemical derivatization by means of the on-column injection technique. Chromatographic separation of the toxins extracted from barley was achieved as a single peak, and the specific EI mass spectra of each toxin were obtained. The fatty acids in the extract that interfere with measurements of the toxins on the gas chromatogram were removed by precipitation as an insoluble metal soap with zinc acetate. Additional clean-up was accomplished using a Bond Elut Florisil cartridge. The quantitative detection limit in barley ranged from 0.1 to 0.5 micrograms/g. The average recoveries of 93.1% for DON, 3ADN, 15MAS, DAS, T-2 and ZEA, and 46.0% for FX and SCT added to barley at the level of 1 microgram/g were obtained.

Determination of isoflavones in soy bean by high-performance liquid chromatography with amperometric detection

Technique de dosage des 4 principales isoflavones (a activite biologique non negligeable) du soja delipide

Determination of Phenolic Anti-Oxidants in Edible Oil by High-Performance Liquid Chromatography with Amperometric Detector

Abstract A high-performance liquid chromatography (HPLC) with amperometric detection was investigated for the analysis of 2-and 3-tert-butyl-4-hydroxyanisole (BHA), 3,5-di-tert−butyl-4-hydroxytoluene (BHT), and tert−butyl-hydroquinone (TBHQ) in edible oil. The reversed-phase system developed was combined with an amperometric detector, the working electrode of which was made of glassy carbon, in order to compare the sensitivity and selectivity of ultraviolet and fluorometric detection. For the amperometric detection of HPLC, cyclic voltammetry was used to monitor the electrochemical properties of the phenolic antioxidants. A simple isolation procedure, based on the continuous liquid-liquid partition technique, was examined for the extraction and clean up of the antioxidants from edible oil. The recovery rates of BHA, BHT, and TBHQ added salad oil were between 90.2-107.7% in the range of 1-50 ppm of the antioxidants. By the present method, BHA, BHT, and TBHQ were well separated, identified and quantitated w...

Enantiomeric separation of atropine in Scopolia extract and Scopolia Rhizome by capillary electrophoresis using cyclodextrins as chiral selectors

Abstract We separated the enantiomers of atropine, a main ingredient of Scopolia extract and Scopolia Rhizome, by capillary electrophoresis. The best conditions for chiral separation were investigated based on the concentration and type of cyclodextrin (CD) used, the pH, the concentration of the electrolyte solution and the capillary temperature. Good resolution of d - and l -hyoscyamine (atropine) was achieved in 100 mM phosphate buffer (pH 2.5) containing 30 mM trimethyl-β-cyclodextrin (TM-β-CD) as the chiral selector. The calibration curves showed good linearity in the range of 10–200 μg/ml (r≥0.99) for d -hyoscyamine, l -hyoscyamine and scopolamine. We could analyze atropine from the samples of crude drugs and pharmaceutical preparations according to the procedures described in The Japanese Pharmacopoeia (Thirteenth Edition).

Liquid chromatographic determination of alliin in garlic and garlic products.

A liquid chromatographic (LC) method is proposed for the determination of alliin in garlic and garlic products. The method involves heating of the sample with water in a bath of boiling water followed by homogenization and centrifugation. Interfering components are eliminated by use of a Sep-Pak C18 cartridge as a clean up step before injection. The LC system with ultraviolet detection at 210 nm consists of a separation on a Zorbax TMS column and isocratic elution with water as a mobile phase. Fluorometric determination by ion-pairing chromatography with tetra-n-butylammonium bromide on a Nucleosil 5C18 column is also described. The overall recoveries of alliin added to garlic products were greater than 90%. Thin-layer chromatography and enzymatic degradation of alliin were performed for the confirmation of alliin detected in garlic products.

High-performance liquid chromatographic analysis of ammonium in human urine

A method for the quantitative determination of ammonium in human urine by high-performance liquid chromatography (HPLC) is described. After making fluorescent substances with fluorescamine, they were separated and quantified by their fluorometric intensity. The intensity (as measured by peak height) was linear between 0.5 and 5.0 micrograms, and coefficients of variation for elution time and peak height on replicate analysis of the standard were 0.15 and 4.2%, respectively. Recoveries of added ammonium were 96.5 and 97.3%, respectively, on 2.0 and 3.0 micrograms by this method. Detection limit of this method was 0.2 microgram. There was good agreement between the proposed HPLC method (X) and ion chromatographic method (Y), giving the relationships as Y = 0.956X + 0.012, r = 0.991.

Composition of fatty acids and their characteristics in oil of instant Chinese noodles.

Twenty-two kinds of oil samples extracted from instant Chinese noodles were analyzed on their composition of fatty acid methyl esters by GC. Four main fatty acids in the oil were 18 : 1, 16 : 0, 18 : 2, and 18 : 0, and another trace ones detected were 14 : 0, 16 : 1, 17 : 0, 17 : 1, 18 : 3+20 : 0, 20 : 1, and 20 : 2. Constraction values of these four main fatty acids were used to evaluate and to calculate the difference among the six producing companies by a personal computer with the analytical method of principal component analysis. Samples were divided into three groups. The constraction values of company B was similar to that of the palm oil and another ones of companies A and E were also similar to that of the mixed oil with the ratio of 25 to 75 on the palm oil and lard.