Residue Determination, Thin-Layer Chromatographic Procedure for Determination of Hydrocortisone Acetate and Alcohol Residues in Milk

1966 ◽  
Vol 14 (1) ◽  
pp. 12-15 ◽  
Author(s):  
R. P. Mooney ◽  
N. R. Pasarela
Keyword(s):  
Thin Layer ◽  
Hydrocortisone Acetate ◽  
Residue Determination ◽  
Chromatographic Procedure

Colorimetric and Gas-Liquid Chromatographic Determination of Atropine-Hyoscyamine and Hyoscine (Scopolamine) in Solanaceous Plants

1975 ◽  
Vol 58 (5) ◽  
pp. 884-887
Author(s):  
Mohamed S Karawya ◽  
Samia M Abdel-Wahab ◽  
Mohamed S Hifnawy ◽  
Mohamed G Ghourab
Keyword(s):  
Citric Acid ◽  
Acetic Anhydride ◽  
Thin Layer ◽  
Chromatographic Determination ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic Determination ◽  
Solanaceous Plants ◽  
Liquid Chromatographic ◽  
Colorimetric Methods

Abstract Two colorimetric micromethods are described for the determination of atropine-hyoscyamine and hyoscine (scopolamine), using p-dimethylaminobenzaldehyde and citric acid-acetic anhydride as the color reagents. These methods are sensitive to 60-1200 and 10-360 μg alkaloid/10 ml. The colorimetric methods were also successfully applied after a preliminary thin layer chromatographic separation of the alkaloids. A gasliquid chromatographic procedure was also developed, which yielded comparable results with the colorimetric methods.

II. Biochemical Investigations

1972 ◽  
Vol 18 (5) ◽  
pp. 462-470 ◽  
Author(s):  
C Rimington ◽  
W G Sears ◽  
L Eales
Keyword(s):  
Solvent Extraction ◽  
Thin Layer ◽  
Soluble Fraction ◽  
Characteristic Pattern ◽  
Chromatographic Technique ◽  
Extraction Procedures ◽  
Felty's Syndrome ◽  
Chromatographic Procedure ◽  
Felty’S Syndrome

Abstract The urinary porphyrin excretion of the patient (Part I) has been examined. Methods for determination of the various porphyrin fractions have also been compared and critically assessed. A thin-layer chromatographic technique was found to be rapid, discriminating, and precise. Of solvent-extraction procedures, that of Rimington and Benson for the determination of urinary "X" porphyrins gives results that compare well with those obtained by the quantitative chromatographic procedure. The patient excreted relatively large amounts of uroporphyrin, heptacarboxylic porphyrin, and "X" porphyrins. In addition, the hydroxycoproporphyrins 1 and 2 of Elder were present in the ether-soluble fraction of her urine in relatively large quantities during the period when the patient was severely ill. Her fecal porphyrins were not markedly increased. The porphyria exhibited by this case of Felty’s syndrome resembled the characteristic pattern of symptomatic porphyria, usually associated with alcoholism, but in this case other factors must be considered because this patient was a life-long abstainer from alcohol.

Simultaneous Detection of Several Fusarium Mycotoxins in Cereals, Grains, and Foodstuffs

1981 ◽  
Vol 64 (5) ◽  
pp. 1067-1073 ◽  
Author(s):  
Hisashi Kamimura ◽  
Motohiro Nishijima ◽  
Kazuo Yasuda ◽  
Kazuo Saito ◽  
Akihiro Ibe ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Thin Layer ◽  
Simultaneous Determination ◽  
Simultaneous Detection ◽  
Fusarium Mycotoxins ◽  
Aqueous Methanol ◽  
Systematic Method ◽  
Chromatographic Procedure ◽  
Cereal Samples

Abstract A systematic method is described for the simultaneous determination of Fusarium mycotoxins (nivalenol, deoxynivalenol, fusarenon-x, diacetoxyscirpenol, neosolaniol, T-2 toxin, HT-2 toxin, butenolide, moniliformin, and zearalenone) in cereals, grains, and foodstuffs. Mycotoxins were extracted with aqueous methanol and purified by a 2-step chromatographic procedure using Amberlite XAD-4 and Florisil columns. The column eluates were concentrated and spotted on a thin layer chromatographic (TLC) plate which was then developed in CHCL3-methanol (93 + 7) and toluene-acetonemethanol (5 + 3 + 2). Each mycotoxin was quantitated by gas chromatography (GO and TLC densitometry. The minimum detectable concentrations (μg/kg) in various test materials were: nivalenol, deoxynivalenol, and fusarenon-x, 2.0; diacetoxyscirpenol, neosolaniol, T-2 toxin, and HT-2 toxin, 80; zearalenone, 10; butenolide, 30; and moniliformin, 50. Recoveries of the mycotoxins added to various cereal samples at 1.0-2.0 Mg/g were greater than 71% and averaged 85%.

Quantitative Determination and Confirmation of Low Levels of Diethylstilbestrol in Feeds

1972 ◽  
Vol 55 (6) ◽  
pp. 1345-1353
Author(s):  
Marshall T Jeffus ◽  
Charles T Kenner
Keyword(s):  
Thin Layer ◽  
Quantitative Determination ◽  
Official Method ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Before And After ◽  
Chromatographic Procedure ◽  
Low Levels ◽  
Cis And Trans

Abstract A method for the determination of diethylstibestrol in feeds, which is based on official first action method 38.048–38.051, is proposed. Interfering feed extractives are removed by using a tripotassium phosphate-Celite column prior to measurement at 415 nm before and after irradiation. Recoveries of equilibrated standards added to Soxhlet extracts of several samples averaged 94.3% compared to 86.3% by the official method. The background absorbance at 415 nm obtained by using the proposed method was approximately 6% of the background by the official method for solutions containing equivalent amounts of sample. A thin layer chromatographic method is also included for the confirmation and identification of the cis and trans isomers of the drug. The proposed method has been found satisfactory for the quantitative determination of 0.55–44 ppm diethylstilbestrol and the thin layer chromatographic procedure can detect as little as 0.07 ppm.

An improved rapid thin-layer chromatographic—gas—liquid chromatographic procedure for the determination of free fatty acids in plasma

1989 ◽  
Vol 183 (2) ◽  
pp. 207-215 ◽  
Author(s):  
Hendrik Y. Tichelaar ◽  
A.J.Spinnler Benadé ◽  
Annette K. Daubitzer ◽  
Theunis J.v.W. Kotze
Keyword(s):  
Fatty Acids ◽  
Thin Layer ◽  
Free Fatty Acids ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic

Determination of l-Phenylazo-2-naphthol in D&C Red No. 17

1967 ◽  
Vol 50 (5) ◽  
pp. 1198-1199
Author(s):  
John C Molitor
Keyword(s):  
Thin Layer ◽  
Chromatographic Procedure

Abstract A thin layer chromatographic procedure is presented in which l-phenyIazo-2-naphthol (PAN) and an unidentified red substance are separated from D&C Red. No. 17 (l-p-phenylazophenylazo-2-naphthoI). PAN is dissolved from the absorbent and determined spectrophotometrically. Recoveries from samples of known composition ranged from 92 to 105%. The PAN content of commercial samples analyzed by this procedure ranged from 0.06 to 1.2%. Unsuccessful attempts to identify the red substance are discussed.

TLC and Spectrophotometric Determination of l[4-(2,5-Dimethoxyphenylazo)-2,5-dimethoxyphenylazo]-2-naphthol and 1,1’-(2,2’,5,5-Tetramethoxy-4,4’-biphenylenebisazo)- di-2-naphthol in Citrus Red No. 2

1970 ◽  
Vol 53 (1) ◽  
pp. 26-28
Author(s):  
Charles Stein
Keyword(s):  
Thin Layer ◽  
Spectrophotometric Determination ◽  
Chromatographic Procedure

Abstract A thin layer chromatographic procedure is presented in which l[4-(2,5-dimethoxyphenylazo)-2,5-dimethoxyphenyIazo]-2-naphthol (dimethoxy color) and l,l’-(2,2’,5,5’-tetramethoxy - 4,4’ - biphenylenebisazo) - di - 2 - naphthol (benzidine color) are separated from Citrus Red No. 2. The compounds are dissolved from the adsorbent and determined spectrophotometrically. Recoveries from samples of known composition ranged from 91 to 104% for the benzidine color and from 89 to 100% for the dimethoxy color. The benzidine colorjcontent of commercial samples ranged from 0.65 to 1.22%; the dimethoxy color content ranged from 0 to 0.22%. The presence of many other subsidiary colors, generally in trace amounts, was noted in all commercial samples.

Simple Derivatization Procedure for Gas-Liquid Chromatographic Analysis of Diflubenzuron in Pond Water and for Analysis of Its Trifluoromethyl Analog Penfluron in Boll Weevils

1978 ◽  
Vol 61 (3) ◽  
pp. 629-635
Author(s):  
Albert B DeMilo ◽  
Paul H Terry ◽  
Diane M Rains
Keyword(s):  
Thin Layer ◽  
Chromatographic Analysis ◽  
Boll Weevil ◽  
Pond Water ◽  
Electron Capture Detection ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic Analysis ◽  
Natural Pond ◽  
Liquid Chromatographic

Abstract A simple and convenient gas-liquid chromatographic procedure involving electron capture detection is described for determining diflubenzuron (N- [[(4-chlorophenyl) amino] carbonyl] - 2,6-difluorobenzamide) in pond water and for determining the uptake of penfluron (trifluoromethyl analog of diflubenzuron) by boll weevils sexually sterilized by this compound. Both compounds were quantitatively converted to their respective N-(trifluoroacetyl) anilines by treatment with trifluoroacetic anhydride and pyridine in benzene at 50–60 °C. In boll weevil analyses, the procedure was quantitative for penfluron at concentrations involving microgram quantities (10–35 ≧g/weevil) without the necessity of a cleanup step. However, at submicrogram quantities, background interference necessitated a thin layer chromatographic cleanup prior to derivatization. This modification enabled the determination of 100 ng/ weevil. Analysis for diflubenzuron in natural pond water gave excellent results. For example, diflubenzuron at 2, 0.2, and 0.02 ppm in pond water was recovered at 95, 82, and 98%, respectively. A mechanism describing the reaction is proposed.

Simple, Rapid Cleanup Method for Analysis of Aflatoxins and Comparison with Various Methods

1985 ◽  
Vol 68 (3) ◽  
pp. 458-461 ◽  
Author(s):  
Hisashi Kamimura ◽  
Motohiro Nishijima ◽  
Kazuo Yasuda ◽  
Hirofumi Ushiyama ◽  
Setsuko Tabata ◽  
...  
Keyword(s):  
Thin Layer ◽  
High Performance ◽  
Rapid Determination ◽  
Hptlc Plate ◽  
Simple Method ◽  
Florisil Column ◽  
Chromatographic Procedure ◽  
Test Materials ◽  
Column Chromatographic

Abstract A method is described for simple and rapid determination of aflatoxins in corn, buckwheat, peanuts, and cheese. Aflatoxins were extracted with chloroform-water and were purified by a Florisil column chromatographic procedure. Column eluates were concentrated and spotted on a high performance thin layer chromatographic (HPTLC) plate, which was then developed in chloroform-acetone (9 + 1) and/or ethermethanol- water (94 + 4.5 + 1.5)orchloroform-isopropanol-acetone (85 + 5 + 10). Each aflatoxin was quantitated by densitometry. The minimum detectable aflatoxin concentrations (μg/kg) in various test materials were 0.2, B1; 0.1, B2; 0.2, G1; 0.1, G2; and 0.1,M1.Recoveries of the aflatoxins added to corn, peanut, and cheese samples at 10-30 μg/kg were > 69% (aflatoxin G2) and averaged 91%, B1; 89%, B2; 91%, G1; 78%, G2; and 92%, M1. The simple method described was compared with the AOAC CB method, AOAC BF method, and AOAC milk and cheese method. These methods were applied to corn, peanut, and cheese composites spiked with known amounts of aflatoxins, and to naturally contaminated buckwheat and cheese. Recoveries were much lower for the BF method compared with our simple method and the CB method.

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