scholarly journals Liquid Chromatographic Determination of Carotenoids and Vitamins A and E in Multivitamin Tablets

1999 ◽  
Vol 82 (1) ◽  
pp. 68-72 ◽  
Author(s):  
Jidong Sun
Keyword(s):  
Ammonium Acetate ◽  
Chromatographic Determination ◽  
Uv Detector ◽  
Retinyl Acetate ◽  
Coefficients Of Variation ◽  
Acid Succinate ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Β Carotene

Abstract Carotenoids and vitamins A and E in multivitamin tablets can be determined simultaneously by reversed-phased liquid chromatography (LC) with a programmable UV detector. Samples were dissolved in dimethyl sulfoxide and thenextracted with hexane. A portion was injected onto a SymmetryC18,150 × 4.6 mm id, 5 μm column and chroma tographed with a mobile phaseof acetonitrile–0.25% ammonium acetate in methanol and 0.05% triethylamine in dichloromethane. A step gradient was used. The system was operated at 25°C with a flow rate of 1.5 mL/min. UV detection was at 325 nm for retinols, 285 nm for tocopherols, and 450 nm for carotenoids. Detection limits were less than 0.3 ng for retinol and retinyl acetate; 2 ng for α-tocopherol acid succinate; 10 ng for α-tocopherol, γ-tocopherol, and α-tocopherol acetate; and 0.4 ng for α-carotene and β-carotene. Intraday and interday coefficients of variation ranged from 1.40 to 5.20%. The sample preparation method and LC assay are practical for quality control and routine analysis of multivitamin tablets.

Liquid Chromatographic Determination of Furazolidone in Swine Serum and Avian Egg

1995 ◽  
Vol 78 (4) ◽  
pp. 1126-1130 ◽  
Author(s):  
Kenichi Yosheda ◽  
Fusao Kondo
Keyword(s):  
Chromatographic Determination ◽  
Accurate Method ◽  
Uv Detector ◽  
Drug Detection ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Swine Serum ◽  
Avian Egg

Abstract A rapid, simple, and accurate method for determination of furazolidone (FZ) in swine serum and avian egg using liquid chromatography (LC) with a 358 nm ultraviolet-visible spectrophotometric detector is described. After liquid–liquid extraction of sample with ethyl acetate using Extrelut-3, the extract is evaporated, redissolved in 40% acetonitrile, and injected directly into the chromatograph. The antibiotic can be analyzed within 30 min. Withinday recoveries for swine serum and avian egg spiked with FZ at 1 ppm were 90.0 and 88.1%, respectively, with coefficients of variation of 3.52 and 3.88%, respectively. Between days recoveries for the 1 ppm samples were 87.2 and 87.0%, with coefficients of variation of 3.10 and 4.29%, respectively. Determination of FZ also was performed by LC/mass spectrometry (MS) with an atmosphericpressure chemical-ionization interface (APCI) system. The LC/MS–APCI system is more applicable for qualitative analysis than quantitative analysis because the drug detection limit (about 0.1 μg/mL) is almost the same as that of the LC–UV detector.

Liquid Chromatographic Determination of Acetic Acid in Foods

1984 ◽  
Vol 67 (5) ◽  
pp. 885-887
Author(s):  
Samy H Ashoor ◽  
Jim Welty
Keyword(s):  
Acetic Acid ◽  
Flow Rate ◽  
Mobile Phase ◽  
Chromatographic Determination ◽  
Uv Detector ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method has been developed for the determination of acetic acid in vinegar and other foods. The LC system includes an Aminex HPX-87H column and a UV detector set at 210 nm. The mobile phase is 0.009N H2S04 at a flow rate of 0.7 mL/min. The method is simple and specific for acetic acid. Recoveries of acetic acid from a variety of products ranged from 93.3 to 102% with coefficients of variation from 2.4 to 4.6%.

High Performance Liquid Chromatographic Determination of Caffeine in Decaffeinated Coffee, Tea, and Beverage Products

1983 ◽  
Vol 66 (3) ◽  
pp. 606-609 ◽  
Author(s):  
Samy H Ashoor ◽  
George J Seperich ◽  
Woodrow C Monte ◽  
Jim Welty
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Uv Detector ◽  
Coefficients Of Variation ◽  
Decaffeinated Coffee ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A method was developed for determining caffeine in decaffeinated coffee, tea, and beverage products by high performance liquid chromatography (HPLC). The HPLC system consisted of a Bio-Sil ODS-5S C18 column, methanol-water (25 + 75) mobile phase at 1 mL/min, and a UV detector. The method is simple and specific. Caffeine recoveries were 93.8-98.3% and coefficients of variation were 0.90-2.25%.

Gas-Liquid Chromatographic Determination of Mirex and Photomirex in the Presence of Poly chlorinated Biphenyls: Interlaboratory Study

1980 ◽  
Vol 63 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Ross J Norstrom ◽  
Henry T Won ◽  
Micheline Van Hove Holdrinet ◽  
Patrick G Calway ◽  
Caroline D Naftel
Keyword(s):  
Chromatographic Determination ◽  
Interlaboratory Study ◽  
Gas Liquid Chromatography ◽  
Coefficients Of Variation ◽  
Fuming Nitric Acid ◽  
Liquid Chromatographic Determination ◽  
Repeatability And Reproducibility ◽  
Concentrated Sulfuric Acid ◽  
Liquid Chromatographic

Abstract Mirex and photomirex (8-monohydromirex) were separated from polychlorinated biphenyls (PCBs) and other aromatic compounds by nitration with fuming nitric acid-concentrated sulfuric acid and removal of nitro-PCBs on an alumina microcolumn; the compounds were then determined by gas-liquid chromatography. Recoveries of Mirex and photomirex were 102±8 and 104±5%, respectively, from standard solutions which had a PCB-to-Mirex and photomirex ratio of 1000. Recoveries from fortified, uncontaminated samples of sediment, fish, and eggs averaged 93±7 and 92±3% for Mirex and photomirex, respectively. The coefficients of variation for repeatability and reproducibility averaged 8 and 15%, respectively, in an interlaboratory study conducted by 4 laboratories using extracts of naturally contaminated substrates (sediment, carp, eel, and gull egg). Levels of Mirex in the samples ranged from 0.1 to 8 mg/kg, and levels of PCB ranged from 0.5 to 166 mg/kg.

High Performance Liquid Chromatographic Determination of Methapyrilene Hydrochloride in Feed and Sleep Aid Tablets

1981 ◽  
Vol 64 (4) ◽  
pp. 889-892
Author(s):  
Badaruddin Shaikh ◽  
Margarette R Hallmark
Keyword(s):  
High Performance ◽  
Ammonium Carbonate ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Reverse Phase ◽  
Phase Partition ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Methapyrilene hydrochloride (MP·HCl) was extracted from feed with methanol and determined by reverse phase partition chromatography in less than 15 min, using isocratic elution with acetonitrile-1.1% ammonium carbonate (1 + 1) as the mobile phase. This procedure was tested on feed treated with MP·HCl at levels of 125,500, and 2000 ppm. Recoveries were 104,95, and 96% with coefficients of variation of 2.4,1.6, and 0.6%, respectively. MP·HCl in feed was stable for 14 days. This method was also successfully used to determine MP·HCl in 3 sleep aid tablets.

Improved Liquid Chromatographic Determination of Riboflavin in Milk and Dairy Products

1985 ◽  
Vol 68 (4) ◽  
pp. 693-696 ◽  
Author(s):  
Samy H Ashoor ◽  
Michael J Knox ◽  
Jacquelyn R Olsen, ◽  
Dru Ann Deger
Keyword(s):  
Dairy Products ◽  
Chromatographic Determination ◽  
Simple Liquid ◽  
Uv Detector ◽  
Aoac Method ◽  
Total Analysis ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Milk And Dairy Products

Abstract Reported here is a simple liquid chromatographic (LC) method for the i determination of riboflavin in milk (liquid, evaporated, and dry), yogurt, ' and cheese. The method involves passing liquid samples or filtrates of semisolid and solid samples through a Clg cartridge. Retained riboflavin is then eluted with an aliquot of 50% methanol in 0.02M acetate buffer of pH 4. A volume of the eluate is injected into the LC system | consisting of a CJ8 column, a solvent of water-methanol-acetic acid (65 + 35 + 0.1, v/v) with a flow rate of 1 mL/min, and a UV detector set at 270 nm. The method is precise and accurate and compares i favorably with the present AOAC method. Moreover, it involves fewer sample preparation steps and has a total analysis time of less than 1 h.

Gas-Liquid Chromatographic Determination of Tetradif on Technical and Formulations: Collaborative Study

1981 ◽  
Vol 64 (4) ◽  
pp. 829-832
Author(s):  
Bram Van Rossum ◽  
Albertus Martijn ◽  
James E Launer ◽  
◽  
E C Calamita ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Flame Ionization ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract The gas-liquid chromatographic determination of tetradifon technical and formulations was collaboratively studied in duplicate with 12 laboratories. Six samples were dissolved in dichloroethane with n-hexacosane as the internal standard, chromatographed on a column of 3% SE-52, and detected by flame ionization. The average coefficients of variation were 1.2% for the 2 technical samples, 1.6% for the 2 wettable powders, and 1.5% for the 2 emulsifiable concentrates. The method has been adopted official first action.

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

1985 ◽  
Vol 68 (3) ◽  
pp. 586-589
Author(s):  
Stephen C Slahck
Keyword(s):  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Normal Phase ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Technical Products

Abstract A liquid chromatographic method for the determination of triadimefon (Bayleton™) in triadimefon technical and formulated products has been developed and subjected to a collaborative study with 7 participating collaborators. Formulations were extracted with mobile solvent and analyzed by normal phase chromatography, with 4-chlorophenyl sulfoxide as an internal standard. Collaborators were furnished with standards and samples of technical products, 50% wettable powders, and 25% wettable powders for analysis. Coefficients of variation of the values obtained on these samples were 1.42, 0.82, and 1.05%, respectively. The method has been adopted official first action.

High Pressure Liquid Chromatographic Determination of 5-(Hydroxymethyl)-2-Furaldehyde in Caramel Solution

1980 ◽  
Vol 63 (6) ◽  
pp. 1310-1313
Author(s):  
Felipe C Alfonso ◽  
Glenn E Martin ◽  
Randolph H Dyer
Keyword(s):  
Chromatographic Determination ◽  
Hplc Method ◽  
Uv Detector ◽  
High Pressure Liquid Chromatographic ◽  
Ethyl Vanillin ◽  
Caramel Color ◽  
Water Gradient ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract An HPLC method is described for the detection of caramel color by measuring the level of 5-(hydroxymethyl)-2-furaldehyde (5-HMF). For the several products of caramelization examined, 5-HMF was the most sensitive indicator of the presence of caramel. The method specifies a reverse phase C18 column, a UV detector set at 277 nm, and a methanol-water gradient to separate 5-HMF from interfering substances. Other flavor compounds resolved by the same gradient are vanillin, ethyl vanillin, coumarin, benzaldehyde, caffeine, anethole, theobromine, and cinnamaldehyde.

Ion Pairing High Pressure Liquid Chromatographic Determination of Amaranth in Licorice Products

1981 ◽  
Vol 64 (6) ◽  
pp. 1411-1413
Author(s):  
William J Hurst ◽  
James M Mckim ◽  
Robert A Martin
Keyword(s):  
High Pressure ◽  
Ion Pairing ◽  
Chromatographic Determination ◽  
Buffer Solution ◽  
High Pressure Liquid Chromatographic ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A high pressure liquid chromatographic method is described for the determination of amaranth (FD&C Red No. 2; Red No. 2) in licorice products. The Red No. 2 is extracted with a basic buffer solution, cleaned up on a Sep-Pak column, chromatographed on a reverse phase column in the ion pairing mode, and detected at 254 nm. The procedure is time-conservative with accurate and precise results. Recovery data ranged from 93 to 104%, and coefficients of variation were less than 4% for standards and samples.

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