Liquid Chromatographic Determination of Protein Acid Hydrolysate Content in Blended Soy Sauce

1985 ◽  
Vol 68 (4) ◽  
pp. 618-621
Author(s):  
Shih-Ling Yeh-Chen ◽  
Chin-Tan Hsu
Keyword(s):  
Liquid Chromatography ◽  
Mobile Phase ◽  
Levulinic Acid ◽  
Protein Hydrolysate ◽  
Chromatographic Determination ◽  
Soy Sauce ◽  
Acid Hydrolysate ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Five methods were investigated for the determination of levulinic acid in soy sauce to determine the addition of protein hydrolysate, mainly acid hydrolysate of defatted soybeans. Best results were obtained by using liquid chromatography (LC) with 0.004M HC104 as the mobile phase and bromcresol purple as a post-column reagent. An innovative LC method with 0.1% H3PO4 as eluant was developed for determination of levulinic acid at 280 nm in soy sauce. This was the most timesaving method.

Liquid-chromatographic determination of 4-hydroxyproline in urine.

1986 ◽  
Vol 32 (6) ◽  
pp. 1002-1004 ◽  
Author(s):  
H Hughes ◽  
L Hagen ◽  
R A Sutton
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Present Method ◽  
High Performance ◽  
Protein Hydrolysate ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract In this method for 4-hydroxyproline in urine, hydroxyproline is derivatized with 4-chloro-7-nitrobenzofurazan, with subsequent estimation by reversed-phase "high-performance" liquid chromatography. The ranges for excretion of free and total hydroxyproline while the subjects were ingesting unrestricted diets were 2-29 and 122-374 mumol/24 h (n = 21), respectively, with no significant sex-related difference. A comparison with results by colorimetry indicated no significant differences: mean (n = 18) concentrations (mumol/L) of hydroxyproline in urine were 180 (SD 149) by the present method, 163 (SD 166) by colorimetry. For protein hydrolysate the respective values were 5.9 (SD 2.7) and 6.7 (SD 2.9).

Liquid Chromatographic Determination of Barbaloin (Aloin) in Foods

1985 ◽  
Vol 68 (3) ◽  
pp. 493-494
Author(s):  
Masatoshi Yamamoto ◽  
Masaaki Ishikawa ◽  
Toshio Masui ◽  
Hiroyuki Nakazawa ◽  
Yozo Kabasawa
Keyword(s):  
Liquid Chromatography ◽  
Present Method ◽  
Mobile Phase ◽  
Chromatographic Method ◽  
Chromatographic Determination ◽  
Food Samples ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A simple and rapid liquid chromatographic method is described for the determination of barbaloin (aloin, 10-D-gIucopyranosyl-l,8-dihydroxy- 3-(hydroxymethyI)-9(10#)-anthracenone) in foods. Barbaloin is extracted with water from foods containing aloe and the extract is cleaned up on a disposable cartridge by using methanol-water (55 + 45) as eluant. The eluted barbaloin is separated by liquid chromatography on a YMC A-302 column with methanol-water (50 + 50) mobile phase, and detected at 293 nm. Recoveries of barbaloin added to foods at the levels of 0.05 and 0.50 mg/g were 94.4-100%. Assay results for commercial food samples indicated that the present method is applicable to a variety of foods supplemented with aloe.

Liquid Chromatographic Determination of 2,4-Dinitro-l-Naphthol and 1-Naphthol in External D&C Yellow No. 7

1983 ◽  
Vol 66 (6) ◽  
pp. 1429-1432
Author(s):  
Allen L Goldberg ◽  
Robert J Calvey
Keyword(s):  
Liquid Chromatography ◽  
Mobile Phase ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Phase Average ◽  
Reproducible Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A sensitive, reproducible method that uses liquid chromatography in the reverse phase mode with a C-18 column is described for determining 2,4-dinitro- 1-naphthol and 1-naphthol in Ext. D&C Yellow No. 7. With this method, these 2 compounds are eluted in a reproducible pattern by increasing the organic nature of a buffered mobile phase. Average recoveries of 2,4-dinitro-l-naphthol and 1-naphthol added to samples of Ext. D&C Yellow No. 7 at levels ranging from 0.003 to 0.20% were 103.9 and 94.7%, respectively.

High-Speed Liquid Chromatographic Determination of o-Phenylphenol Residues in Citrus Products

1976 ◽  
Vol 59 (1) ◽  
pp. 162-164
Author(s):  
Samuel K Reeder
Keyword(s):  
Liquid Chromatography ◽  
Quantitative Analysis ◽  
High Speed ◽  
Steam Distillation ◽  
Chromatographic Determination ◽  
Analysis Time ◽  
Hexane Extraction ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A method is presented for the quantitative analysis of o-phenylphenol residues in citrus oils, encapsulated flavors, and dried meal. The method utilizes high-speed liquid chromatography for the determination after specific sample preparations for each material. These preparations include hexane extraction of acidified basic extracts or steam distillation and extraction. The limit of the analysis is <1 ppm with an analysis time of <45 min.

Improved liquid-chromatographic determination of haloperidol in plasma.

1984 ◽  
Vol 30 (7) ◽  
pp. 1228-1230 ◽  
Author(s):  
A K Dhar ◽  
H Kutt
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Room Temperature ◽  
Internal Standard ◽  
Isoamyl Alcohol ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract This method for determination of haloperidol in plasma is based on "high-performance" isocratic liquid chromatography with the use of a C8 bonded reversed-phase column at room temperature. Haloperidol and the internal standard (chloro-substituted analog) are extracted from alkalinized plasma into isoamyl alcohol/heptane (1.5/98.5 by vol) and back-extracted into dilute H2SO4. The aqueous phase is directly injected onto the column. The mobile phase is a 30/45/25 (by vol) mixture of phosphate buffer (16.5 mmol/L, pH 7.0), acetonitrile, and methanol. Unlike other liquid-chromatographic procedures for haloperidol, commonly used psychotropic drugs do not interfere. Analysis can be completed within an hour. The procedure is extremely sensitive (1.0 microgram/L) and is well reproducible (CV 5.6% for a 2.5 micrograms/L concentration in plasma).

Gas-Liquid Chromatographic Determination of Sodium Fluoroacetate (Compound 1080)

1980 ◽  
Vol 63 (1) ◽  
pp. 49-55
Author(s):  
Iwao Okuno ◽  
Dennis L Meeker
Keyword(s):  
Liquid Chromatography ◽  
Tissue Sample ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
Tissue Samples ◽  
Fluoroacetic Acid ◽  
Pentafluorobenzyl Bromide ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract An analytical method is described for the determination of Compound 1080 (sodium fluoroacetate) residues in 1–10 g tissue. Sample extracts of tissues are cleaned up with silica gel, and Compound 1080 (as fluoroacetic acid) is separated by a micro-distillation procedure. The fluoroacetic acid in the distillate is derivatized with pentafluorobenzyl bromide to form pentafluorobenzyl fluoroacetate which is measured by electron capture gas-liquid chromatography. Recoveries of sodium fluoroacetate from fortified tissue samples averaged about 25%. Despite the limited recoveries, results were quite reproducible, and levels as low at 2 ppm were determined in fortified 1 g samples, and 0.2 ppm in 10 g samples. The method is relatively simple and has been used routinely in our laboratory for the analysis of various types of samples such as grain, and tissues from birds, rodents, and larger animals.

Gas-Liquid Chromatographic Determination of Maleic Hydrazide in Tobacco and Tobacco Smoke

1979 ◽  
Vol 62 (1) ◽  
pp. 171-175 ◽  
Author(s):  
Alfred F Haeberer ◽  
Orestes T Chortyk
Keyword(s):  
Liquid Chromatography ◽  
Tobacco Smoke ◽  
Plant Growth Regulator ◽  
Maleic Hydrazide ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
Trimethylsilyl Derivative ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A method is presented for the determination of the plant growth regulator maleic hydrazide (MH; l,2-dihydro-3,6-pyridazinedione) in tobacco and tobacco smoke. Residues are converted to the bis(trimethylsilyl) derivative before analysis by gas-liquid chromatography. The method has been applied to cigarettes and condensed smoke and has been used to determine the per cent transfer of MH into cigarette smoke. Free MH residues could be determined directly on the tobacco samples, whereas total MH values were obtainable only after acid hydrolysis. In spite of large MH residues in tobacco, only 0.2% of the MH was transferred into smoke.

Gas-Liquid Chromatographic Determination of Total Inorganic Iodine in Milk

1977 ◽  
Vol 60 (6) ◽  
pp. 1307-1309 ◽  
Author(s):  
Hendrik J Bakker
Keyword(s):  
Liquid Chromatography ◽  
Iodine Content ◽  
Chromatographic Determination ◽  
Electron Capture Detection ◽  
Gas Liquid Chromatography ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Inorganic Iodine ◽  
Liquid Chromatographic

Abstract Total inorganic iodine in milk is determined by conversion to iodobutanone, which is quantitated by gas-liquid chromatography and electron capture detection. As little as 10 μg/L can be determined. The thyroid-active iodine content of milk can be determined rapidly with a relative standard deviation of 1.9%. Average recoveries for added iodide and iodine were 95.5 and 94.6%, respectively.

Liquid Chromatographic Determination of Carbofuran in Technical and Formulated Products: Collaborative Study

1986 ◽  
Vol 69 (5) ◽  
pp. 915-918
Author(s):  
Edward J Kikta ◽  
◽  
E Bane ◽  
A Burns ◽  
A Christensen ◽  
...  
Keyword(s):  
Mobile Phase ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Data Sets ◽  
Matched Pairs ◽  
Reverse Phase ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method for the analysis of technical and formulated carbofuran samples was evaluated in a collaborative study. Carbofuran is determined by reverse phase LC, using a water-methanol mobile phase and acetophenone as internal standard, and detected at 280 nm. Twelve samples, 5 formulations and technical matched pairs, were analyzed by 17 collaborating laboratories. Accuracy and variability of results are typical of large LC data sets. The method has been adopted official first action.

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