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.

Collaborative Study of the Quantitative Gas-Liquid Chromatographic Determination of Fusel Oil and Other Components in Whisky

1972 ◽  
Vol 55 (3) ◽  
pp. 549-556
Author(s):  
J H Kahn ◽  
E T Blessinger
Keyword(s):  
Ethyl Acetate ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
Official Method ◽  
Fusel Oil ◽  
Fusel Alcohols ◽  
Aoac Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Fifteen chemists participated in a collaborative study for the quantitative pas-liquid chromatographic determination of the individual fusel alcohols and ethyl acetate in whisky. Two levels of congeners represented by 4 coded samples of whisky were analyzed by using t h e proposed method, employing a glycerol-1,2,6-hexanetriol column, and the official AOAC method, 9.063-9.065. Since isobutyl and the atnyl alcohols comprise by far the greatest part of fusel oil, their determination is of major importance to the total fusel oil content . Statistical analyses show that the proposed method is superior to the AOAC method for the determination of these alcohols, whereas the official method is superior for the determination of ethyl acetate and n-propyl alcohol. In general, collaborators employing modern instrumentation preferred the proposed method over the AOAC method. The former method also separates and permits the quantitative measurement of active amyl and isoamyl alcohols. The proposed method has been adopted as official first action as an alternative to 9.063–9.065 for the determination of higher alcohols and ethyl acetate in whisky.

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.

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.

Simple Liquid Chromatographic Determination of Minocycline in Brain and Plasma

2007 ◽  
Vol 65 (5-6) ◽  
pp. 277-281 ◽  
Author(s):  
A. Milane ◽  
C. Fernandez ◽  
G. Bensimon ◽  
V. Meininger ◽  
R. Farinotti
Keyword(s):  
Chromatographic Determination ◽  
Simple Liquid ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Rapid Reverse Phase Liquid Chromatographic Determination of Aflatoxin M1 in Milk

1985 ◽  
Vol 68 (3) ◽  
pp. 462-465
Author(s):  
Ahmed E Yousef ◽  
Elmer H Marth
Keyword(s):  
Extraction Procedure ◽  
Chromatographic Determination ◽  
New Method ◽  
Aflatoxin M1 ◽  
Cleanup Procedure ◽  
Aoac Method ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A rapid, economical, and reliable liquid chromatographic (LC) method is described for determination of aflatoxin M, in milk. The method includes an improved AOAC extraction procedure, cleanup of the extract on a silica cartridge, and LC quantitation. Alternatively, a rapid column cleanup procedure can be used. Milk artificially spiked with aflatoxin M1 at 0.05, 0.1, and 0.5 ppb was analyzed using both new approaches as well as an AOAC method coupled with LC for quantitation of the toxin. Recovery of aflatoxin M1 by the first approach of the new method ranged between 93.4 and 99.1%, and for the alternative procedure between 92.4 and 96.8%. The AOAC method gave lower recovery (85.6-90.7%) of toxin, but the results from this method had a somewhat smaller standard deviation for replicate analyses than did results of the new method.

Liquid Chromatographic Determination of Acifluorfen in Soil and Water

1990 ◽  
Vol 73 (4) ◽  
pp. 599-601
Author(s):  
Mara Gennari ◽  
Michèle Negre ◽  
Alessandro Cignetti
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Chromatographic Determination ◽  
Phase Extraction ◽  
Uv Detector ◽  
Liquid Chromatograph ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Soil And Water

Abstract An analytical method based on the use of a liquid chromatograph equipped with a UV detector was developed for the determination of acifluorfen In soil and water. Acifluorfen was extracted from soil In methanol-0.10N NaOH (80 + 20 v/ v) and from water by partition with dlchloromethane. Solvent partitioning and solid-phase extraction were used to separate acifluorfen from major Interfering sample components. Average recoveries from soil at 1, 0.1, and 0.01 ppm fortification levels were 95.1 ± 3.4,92.6 ± 2.9, and 73.9 ± 3.0%, respectively. Recoveries from water spiked at levels from 0.01 to 1 ppm averaged 96.5 ± 5.4%. Method limits of detection were 0.006 ppm in soil and 0.003 ppm In water.

Liquid Chromatographic Determination of Aflatoxin M1 in Milk

1984 ◽  
Vol 67 (4) ◽  
pp. 739-741
Author(s):  
Krystyna Tyczkowska ◽  
James E Hutchins ◽  
Winston M Hagler
Keyword(s):  
Limit Of Detection ◽  
Bovine Milk ◽  
Chromatographic Determination ◽  
Aflatoxin M1 ◽  
Aoac Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Chloroform Methanol ◽  
Porcine Milk

Abstract The official AOAC method for aflatoxin M, in milk was modified by replacing cellulose column chromatography with cartridge chromatographic cleanup and replacing thin layer chromatographic (TLC) determination with liquid chromatographic (LC) quantitation to yield a new method for bovine and porcine milk. An acetone extract of milk is treated with lead acetate and defatted with hexane, and M1 is partitioned into chloroform as in the AOAC method. Chloroform is removed by evaporation under a stream of nitrogen at 50°C. The residue is dissolved in chloroform, the vessel is rinsed with hexane, and the 2 solutions are applied in sequence to a hexane-activated silica Sep-Pak cartridge. Less polar impurities are removed with hexane-ethyl ether, and M1 is eluted with chloroform-methanol, and determined by C18 reverse phase LC using fluorescence detection. Recoveries of M, added to bovine milk at 0.25, 0.50, and 1.0 ng/mL were 90.8, 93.4, and 94.1%, respectively. The limit of detection was less than 0.1 ng M,/mL for both bovine and porcine milk.

Gas-Liquid Chromatographic Determination of Phenothiazine in Medicated Feeds

1973 ◽  
Vol 56 (1) ◽  
pp. 174-176
Author(s):  
Billy M Colvin ◽  
Albert E Prudom ◽  
Larry L Whitlock ◽  
Alan R Hanks
Keyword(s):  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Good Precision ◽  
Gas Chromatograph ◽  
Aoac Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Medicated Feeds

Abstract A simple and rapid method is described for the determination of phenothiazine in feeds. Phenothiazine is extracted with chloroform containing chlorobenzilate as an internal standard. The extract is injected into a gas chromatograph and peak height ratios are used for quantitation. The analysis of commercial samples shows that the method compares well with the more commonly employed colorimetric AOAC method, and good precision, with recoveries ranging from 96.0 to 99.9%, is obtained in the analysis of prepared samples.

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.

scholarly journals Rapid Extraction of Aflatoxin from Creamy and Crunchy Peanut Butter

2005 ◽  
Vol 88 (5) ◽  
pp. 1383-1386 ◽  
Author(s):  
Victor A Vega
Keyword(s):  
Aflatoxin B1 ◽  
Peanut Butter ◽  
Chromatographic Determination ◽  
Rapid Extraction ◽  
Waste Production ◽  
Aoac Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Different Levels

Abstract A rapid extraction technique was developed for the isolation and subsequent liquid chromatographic determination of aflatoxins B1, B2, G1, and G2 in creamy and crunchy peanut butter. Peanut butter samples were extracted with a methanol 15% sodium chloride (7 + 3) solution followed by a second extraction with methanol. The extract was subjected to a cleanup using a Vicam Aflatest® immunoaffinity column. Control samples for both smooth and crunchy peanut butter were fortified at 4 different levels for aflatoxin B1, B2, G1, and G2. The average aflatoxin B1, B2, G1, and G2 recoveries from smooth peanut butter were 95.2, 89.9, 94.1, and 62.4%, respectively, and 92.4, 84.3, 85.5, and 53.7%, respectively, from crunchy peanut butter. This extraction method and the official AOAC Method 991.31 produced comparable results for peanut butter samples. This method provides a rapid, specific, and easily controlled assay for the analysis of aflatoxins in peanut butter with minimal solvent usage. Organic solvent consumption was decreased by 85% and hazardous waste production was decreased by 80% in comparison with the AOAC method. Along with the decreased solvent consumption, significant savings in time were observed.

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