Liquid Chromatographic Determination of Thiamine, Riboflavin, and Pyridoxine in Infant Formula

1992 ◽  
Vol 75 (3) ◽  
pp. 561-565 ◽  
Author(s):  
George W Chase ◽  
William O Landen ◽  
Ronald R Eitenmiller ◽  
Abdel-Gawad M Soliman
Keyword(s):  
Internal Standard ◽  
Ammonium Hydroxide ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Acid Sodium Salt ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract An Ion pairing reversed-phase liquid chromatographic method developed for multivitamin supplements and premlxes was applied to the simultaneous determination of thiamine, riboflavin, and pyridoxine In perchloric acid extracts of milkand soy-based Infant formulas. The method uses m-hydroxy benzoic acid as Internal standard and a mobile phase consisting of water, acetonltrile, hexanesulfonlc acid sodium salt, and ammonium hydroxide solution, adjusted to pH 3.6 with phosphoric acid. The column Is a 15 cm x 3.9 mm id Nova Pak C18. Limits of detection were 0.15 μg/mL for thiamine and 0.09 μg/mL for riboflavin by UV detection at 254 nm, and 0.010 μg/mL for pyridoxine by fluorescence detection. Mean percent recoveries based on triplicate determinations were 102 ± 1.8,102 ± 3.3, and 101 ± 3.1 for thiamine, riboflavin, and pyridoxine, respectively. The results compared favorably with the AOAC methods for thiamine, riboflavin, and pyridoxine.

Method Modification for Liquid Chromatographic Determination of Thiamine, Riboflavin, and Pyridoxine in Medical Foods

1993 ◽  
Vol 76 (6) ◽  
pp. 1276-1280 ◽  
Author(s):  
G William Chase ◽  
William O Landen ◽  
Abdel-Gawad M Soliman ◽  
Ronald R Eitenmiller
Keyword(s):  
Fluorescence Detection ◽  
Ammonium Hydroxide ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Acid Sodium Salt ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Medical Foods ◽  
Liquid Chromatographic

Abstract A reversed-phase ion pair liquid chromatographic method developed for the simultaneous determination of thiamine (B1), riboflavin (B2), and pyridoxine (B6) in perchloric acid extracts of infant formulas was modified to include medical foods. UV detection of B1 and B2 was replaced by fluorescence detection, which resulted in improved sensitivity and specificity. B1 was detected by fluorescence after conversion to thiochrome by a postcolumn reaction with sodium hydroxide and potassium ferricyanide. The method uses a mobile phase of water, acetonitrile, hexanesulfonic acid sodium salt, ammonium hydroxide, and phosphoric acid adjusted to pH 3.6. The column is a 300 × 3.9 mm Nova Pak C18. Limits of detection were 0.05 μg/mL for B1 and B2 and 0.01 μg/mL for B6 by fluorescence detection. The system reproducibility was evaluated by completing 10 repetitive determinations on a medical food that gave a coefficient of variation of 5.9, 6.0, and 10.7% for B1, B2, and B6, respectively. Mean recoveries (n = 10) were 111,96.3, and 113% for B1, B2, and B6, respectively. The results compared favorably with those by AOAC Official Methods 942.23, 940.33, and 961.15 for B1, B2, and B6, respectively.

Liquid Chromatographic Determination of Thiamine in Rodent Feed by Postcolumn Derivatization and Fluorescence Detection

1995 ◽  
Vol 78 (2) ◽  
pp. 307-309 ◽  
Author(s):  
Theresa A Gehring ◽  
Willie M Cooper ◽  
Claude L Holder ◽  
Harold C Thompson
Keyword(s):  
Chromatographic Determination ◽  
Reversed Phase ◽  
Detector Response ◽  
Fluorescence Excitation ◽  
Liquid Chromatographic Method ◽  
Essential Nutrient ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method was developed for determination of the essential nutrient thiamine (vitamin Bi) in rodent feed. Thiamine was extracted with hydrochloric acid, separated by reversed-phase liquid chromatography, derivatized postcolumn to thiochrome with potassium hydroxide and potassium ferricyanide, and detected by fluorescence. Excitation and emission wavelengths were 370 and 430 nm, respectively. Detector response was linear in the range of 2.58 to 15.5 ng of thiamine injected. Instrument detection limit was 5 pg of thiamine injected.

Liquid-chromatographic determination of pentobarbital in plasma with use of a resin column and an alkaline mobile phase.

1982 ◽  
Vol 28 (8) ◽  
pp. 1772-1774 ◽  
Author(s):  
R N Gupta ◽  
P T Smith ◽  
F Eng
Keyword(s):  
Mobile Phase ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Enhanced Sensitivity ◽  
Acidic Drugs ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract We describe a liquid-chromatographic method involving a new, nonsilica column (XAD-2, Hamilton Co.) for pentobarbital in plasma. Plasma is extracted with chloroform after addition of the internal standard, 5-ethyl-5-p-tolyl-barbituric acid. Acidic drugs are back-extracted into alkali, then chromatographed on the resin-base reversed-phase column. The use of alkaline mobile phase allows enhanced sensitivity and detection of barbiturates at 240 nm. The within-run CV for 10 samples was 1.9%, the between-run CV 1.8%. Ten commonly used barbiturates are separated isocratically in less than 15 min. Other commonly prescribed acidic drugs do not interfere with determination of pentobarbital.

scholarly journals Liquid Chromatographic Determination of Scopolamine, Hyoscyamine, and Phenobarbital in Tablets

1997 ◽  
Vol 80 (2) ◽  
pp. 331-334 ◽  
Author(s):  
Susan Ting
Keyword(s):  
Mobile Phase ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Scopolamine Hydrobromide ◽  
Acid Sodium Salt ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method using a reversed- phase C18 column and octanesulfonic acid sodium salt-methanol as the mobile phase was developed for the simultaneous determination of phenobarbi- tal, scopolamine, and hyoscyamine in tablets. The mixture of the 3 drugs was resolved in <8 min. Detector responses were linear for 10 μL injections of the following: scopolamine hydrobromide, 8.25-206.3 μg/mL; hyoscyamine sulfate, 15.01-750.76 μg/mL; and phenobarbital, 250-751 μg/mL. Recoveries from tablets were 100.8% for scopolamine hydrobromide, 100.1% for hyoscyamine sulfate, and 100.3% for phenobarbital. Replicate injections of scopolamine hydrobromide, hyoscyamine sulfate, and phenobarbital gave an overall relative standard deviation of <1.0% (n = 10). The method detected as little as 3.3 ng scopolamine hydrobromide.

Liquid Chromatographic Determination of Aflatoxin M1 in Milk Powder Using Immunoaffinity Columns for Cleanup: Interlaboratory Study

1993 ◽  
Vol 76 (6) ◽  
pp. 1248-1254 ◽  
Author(s):  
Louis G M Th Tuinstra ◽  
Arie H Roos ◽  
John M P Van Trijp ◽  
◽  
P A Burdaspal ◽  
...  
Keyword(s):  
Milk Powder ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Interlaboratory Study ◽  
Aflatoxin M1 ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method for determining low aflatoxin M1 concentrations in milk was evaluated in an International Dairy Federation (IDF) interlaboratory study. The study involved 16 participants from 11 countries. The method, chosen after a comparison of several methods by a preparatory group, uses an immunoaffinity column for cleanup. As the sample passes through the column, antibodies selectively bind with aflatoxin M1 (antigen) present and form an antibody-antigen complex. All other components of the sample matrix are washed off the column with water. Then, aflatoxin M1 is eluted from the column with acetonitrile, which is collected. Final determination is carried out by reversed-phase liquid chromatography with fluorescence detection. Over the tested range (80-600 ng aflatoxin M1/kg milk powder), an RSDR ranging from 11 to 23% was obtained by analyzing 24 samples (blind duplicates), 2 samples of which were blanks.

Reversed-Phase Liquid Chromatographic Determination of Cromolyn Sodium in Drug Substance and Select Dosage Forms

1994 ◽  
Vol 77 (6) ◽  
pp. 1689-1694 ◽  
Author(s):  
Linda L Ng
Keyword(s):  
Technical Communication ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Dosage Forms ◽  
Liquid Chromatographic Method ◽  
Validation Parameters ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract This study, presented as a technical communication, describes a reversed-phase liquid chromatographic method for select commercial formulations, namely, inhalation solution, nasal solution, capsule and inhalation aerosol. Miscellaneous validation parameters are also discussed.

Liquid Chromatographic Determination of Flucytosine in Capsules: Collaborative Study

1988 ◽  
Vol 71 (1) ◽  
pp. 33-35
Author(s):  
Donald Shostak ◽  
Clifford Klein ◽  
◽  
C Cappon ◽  
N Falcone ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Photometric Detection ◽  
Acid Sodium Salt ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
The Mean ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method for the determination of flucytosine in capsules was collaboratively studied by 7 laboratories. The method uses a C18 reverse phase column, water-methanol-acetic acid mobile phase containing 1-octanesulfonic acid sodium salt, p-aminobenzoic acid as internal standard, and photometric detection at 285 nm. The mean recovery value (±SD) of flucytosine from a synthetic formulation representing capsules was 99.2 ± 1.72% (CV = 1.73%). Composited samples of 250 and 500 mg commercial capsules gave assay values of (mean ± SD) 103.17 ± 2.21 and 99.29 ± 1.29% of declared, respectively. CV values were 2.15 and 1.30%. Reproducibility and repeatability CVs were 2.19 and 1.50%, respectively, for the 250 mg capsules, and 1.34 and 0.63%, respectively, for the 500 mg capsules. The method has been adopted official first action.

Liquid-chromatographic determination of ethylene glycol in plasma.

1982 ◽  
Vol 28 (1) ◽  
pp. 32-33 ◽  
Author(s):  
R N Gupta ◽  
F Eng ◽  
M L Gupta
Keyword(s):  
Liquid Chromatography ◽  
Ethylene Glycol ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Standard Curve ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract In this novel procedure for determining ethylene glycol in plasma by liquid chromatography, benzoyl esters of ethylene glycol and of benzyl alcohol (used as the internal standard) are prepared directly in plasma. The benzoyl esters, highly ultraviolet-absorbing chromogens, are ideal compounds for analysis by reversed-phase liquid chromatography with methanol/water as the mobile phase. The benzoyl derivative of ethylene glycol is well separated from the derivative of the internal standard and from plasma constituents. The standard curve is linear to 400 mg of ethylene glycol per liter. As little as 10 mg of ethylene glycol per liter of plasma can be measured. Other commonly ingested alcohols do not interfere.

Determination of Sulfamethazine in Bovine and Porcine Tissues by Reversed-Phase Liquid Chromatography

1994 ◽  
Vol 77 (3) ◽  
pp. 558-564 ◽  
Author(s):  
Joe O K Boison ◽  
Lily J-Y Keng
Keyword(s):  
Internal Standard ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Dihydrogen Phosphate ◽  
Sodium Dihydrogen Phosphate ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic ◽  
Layer Chromatography

Abstract A simple, sensitive, and rapid method for the liquid chromatographic determination of sulfamethazine in animal tissues was developed by using sulfaethoxypyridazine as the internal standard. Homogenized tissue is extracted with chloroform, and the sulfa drugs are back-extracted from chloroform into alkaline sodium chloride solution. The pH of the aqueous extract is adjusted to 6, and the sulfas are concentrated on a conditioned C18 cartridge and eluted with 1 mL methanol. Sulfamethazine and sulfaethoxypyridazine are separated from tissue co-extractives by reversed-phase chromatography on a C18 column by using 0.05M sodium dihydrogen phosphate-methanol (7 + 3). Detection is performed at 265 nm. The method has a detection limit of 2 ng/g. Results obtained by this method were compared with those obtained by the official thin-layer chromatography/densitometric method.

Simultaneous Liquid Chromatographic Determination of Fenamiphos and Its Metabolites in Soil

1992 ◽  
Vol 75 (1) ◽  
pp. 62-65 ◽  
Author(s):  
R Khazanchi ◽  
S Walia ◽  
S K Handa
Keyword(s):  
Chromatographic Method ◽  
Limit Of Detection ◽  
Degradation Products ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A reversed-phase liquid chromatographic method has been developed for the determination of fenamiphos and the metabolites fenamiphos sulfoxide, fenamiphos sulfone, 3-methyl-4-(methylthlo)- phenol, and 3-methyl-4-(methylsulflnyl)phenol. Trace quantities of the nematlclde and Its metabolites In soil can be determined simultaneously. The limit of detection of the method was 5 ppm. Recoveries of fenamiphos and Its degradation products at fortification levels of 25,50, and 100 ppm ranged from 99.2 to 100.8%. Standard deviations ranged from 0.29 to 0.70 ppm.

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