Liquid Chromatographic Determination of Vanillin and Related Flavor Compounds in Vanilla Extract: Cooperative Study

1985 ◽  
Vol 68 (6) ◽  
pp. 1198-1201 ◽  
Author(s):  
Philip A Guarino ◽  
Susan M Brown
Keyword(s):  
Collaborative Study ◽  
Chromatographic Determination ◽  
Technical Committee ◽  
Flavor Compounds ◽  
Official Method ◽  
Ethyl Vanillin ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract Vanillin and related flavor compounds present in vanilla extract were determined by reverse phase liquid chromatography. Results compared favorably with the official AOAC spectrophotometric method. Compounds such as p-hydroxybenzaldehyde and ethyl vanillin known to interfere in the official method were resolved from vanillin. The method was evaluated by 6 industrial laboratories under the aegis of the Technical Committee of the Flavor and Extract Manufacturers Association. The method is suggested for AOAC collaborative study.

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.

Liquid Chromatographic Determination of Methocarbamol in Injection and Tablet Dosage Forms: Collaborative Study

1984 ◽  
Vol 67 (2) ◽  
pp. 225-227 ◽  
Author(s):  
Richard L Everett ◽  
◽  
L Allgire ◽  
R J Ballbach ◽  
J Booth ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Chromatographic Determination ◽  
Dosage Forms ◽  
Ultraviolet Detector ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Tablet Dosage ◽  
Liquid Chromatographic

Abstract A reverse phase liquid chromatographic method was developed for determining methocarbamol in injection and tablet dosage forms. The injections require dilution only; the tablets require a nitration step before introduction into the chromatograph. Response for methocarbamol was linear over the range 0-18 μg, using an ultraviolet detector at 274 nm. Recoveries by the author ranged from 96.1 to 101.9% for authentic injection formulations and 98.0 to 101.0% for authentic tablet formulations. A collaborative study of the method by 6 laboratories resulted in standard deviations of 1.70 and 2.22 for injection and tablet dosage forms, respectively. The method has been adopted official first action.

Liquid Chromatographic Determination of Methyldopa and Methyldopa-Thiazide Combinations in Tablets: Collaborative Study

1984 ◽  
Vol 67 (6) ◽  
pp. 1118-1120
Author(s):  
Ting Susan ◽  
◽  
R L Brown ◽  
L A Dougherty ◽  
J B Schepman ◽  
...  
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Repeatability And Reproducibility ◽  
Liquid Chromatographic

Abstract A reverse phase liquid chromatographic method for the determination of methyldopa, methyldopa-hydrochlorothiazide, and methyldopachlorothiazide in tablets was collaboratively studied by 8 laboratories. Each collaborator received 20 samples that included drug substance, synthetic and commercial tablet compositions. The overall repeatability and reproducibility standard deviations for commercial tablets were 1.11 and 1.75% for methyldopa, 0.96 and 1.62% for chlorothiazide, and 1.21 and 2.15% for hydrochlorothiazide, respectively. The overall recoveries of methyldopa, chlorothiazide, and hydrochlorothiazide added to synthetic tablets were 100.78, 100.70, and 101.34%, respectively. The method has been adopted official first action.

Liquid Chromatographic Determination of Hydrocortisone in Bulk Drug Substance and Tablets: Collaborative Study

1984 ◽  
Vol 67 (2) ◽  
pp. 218-221 ◽  
Author(s):  
Milda J Walters ◽  
◽  
N Falcone ◽  
K G Hanel ◽  
E H Jefferson ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Chromatographic Determination ◽  
Normal Phase ◽  
Drug Substance ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Bulk Drug ◽  
Liquid Chromatographic

Abstract A normal phase liquid chromatographic (LC) method for determining the hydrocortisone content of bulk drug substance, tablet composites, and individual tablets was subjected to a collaborative study by 6 laboratories. The results showed a mean recovery of 98.5% for an authentic tablet formulation and reproducibility coefficients of variation of 0.97, 1.6, and 2.7% for bulk drug substance, tablet composites, and individual tablets, respectively. Infrared (IR) and thin layer chromatographic (TLC) identification tests, also included in the collaborative study, were satisfactory. The LC method for determining hydrocortisone in bulk drug substance, tablet composites, and individual tablets, with IR and TLC identification, has been adopted official first action.

Reverse-Phase Liquid Chromatographic Determination of Clioquinol in Cream and Ointment Preparations: Collaborative Study

1989 ◽  
Vol 72 (4) ◽  
pp. 562-563
Author(s):  
Edward J Wojtowicz
Keyword(s):  
Ammonium Acetate ◽  
Collaborative Study ◽  
Internal Standard ◽  
Nickel Chloride ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract Seven laboratories participated in a collaborative study to analyze, in duplicate, 2 synthetic formulations and 2 commercial preparations, labeled to contain 3% clioquinol. Clioquinol is determined as its nickel (II) complex by reverse-phase liquid chromatography on a phenylbonded column with a mobile phase of acetonitrile-methanol-water, containing ammonium acetate and nickel chloride. Detection is at 273 nm and diphenylamine is added as an internal standard. Mean recoveries were 99.1 and 101.1%, respectively, for the ointment and cream synthetic preparations and 96.7 and 99.7%, respectively, for the commercial ointment and cream. All results are consistent with the variability of other methods at this concentration range. The method has been approved interim official first action

Liquid Chromatographic Determination of Acetaminophen in Tablets: Collaborative Study

1987 ◽  
Vol 70 (2) ◽  
pp. 212-214
Author(s):  
David J Krieger
Keyword(s):  
Collaborative Study ◽  
Chromatographic Determination ◽  
Generic Product ◽  
Single Component ◽  
Reverse Phase ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A reverse phase liquid chromatographic method previously reported for the determination of acetaminophen in tablets was collaboratively studied by 5 laboratories. Each collaborator received duplicate samples of a synthetic tablet formulation and 3 powdered commercial tablet composites. The composites represented single-component and multi-component proprietary products and a single-component generic product. The pooled repeatability (CVD„) and reproducibility (CVDJ values for the proprietary tablets were 0.89 and 1.34%, respectively. For the generic tablets, these values were 0.66 and 0.74%, respectively. The pooled recovery value for acetaminophen added to the synthetic formulation was 98.9 ± 0.7% (n = 10) with a CV of 0.75%, CVD„ of 0.37%, and CVD„ of 0.78%. The overall repeatability of the method was 0.64%, and the overall reproducibility was 0.95%. The method has been adopted official first action.

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

1994 ◽  
Vol 77 (2) ◽  
pp. 328-330
Author(s):  
Thomas M Schmitt
Keyword(s):  
Collaborative Study ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Relative Standard ◽  
Before And After ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
The Mean ◽  
Liquid Chromatographic

Abstract An isocratic reversed-phase liquid chromatographic (LC) procedure for measuring bentazon in commercial herbicide products and aqueous formulations was collaboratively studied by 16 laboratories. Samples are dissolved in LC eluent [0.075M sodium acetate–methanol (60 + 40)] and analyzed by LC on a 30 cm × 3.9 mm octadecylsilyl column with detection by UV absorbance at 340 nm. The quantity of active ingredient is determined by comparing the mean response factor (RF) of the sample to the mean RF of standards injected just before and after each pair of sample injections. The average relative standard deviation (RSDR) for 3 formulations studied was 1.54%; the RSDR for a technical sample was 0.77%. The method has been adopted first action by AOAC INTERNATIONAL.

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

1994 ◽  
Vol 77 (1) ◽  
pp. 8-10
Author(s):  
Alan R Hanks
Keyword(s):  
Collaborative Study ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Reversed Phase Liquid Chromatography ◽  
Buffer Solution ◽  
External Standard ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract Phosphamidon is determined by reversed-phase liquid chromatography on a C18 column with a mobile phase of acetonitrile—methanol buffer solution, detected by a UV absorbance detector set at 218 nm, and quantitated by area measurements using an external standard. The method was adopted first action by AOAC INTERNATIONAL.

Liquid Chromatographic Determination of Zoalene in Medicated Feeds

1984 ◽  
Vol 67 (5) ◽  
pp. 861-862 ◽  
Author(s):  
John Morawski ◽  
Glenn Kyle
Keyword(s):  
Colorimetric Method ◽  
Chromatographic Determination ◽  
Activated Alumina ◽  
Reverse Phase ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Aoac Official ◽  
Liquid Chromatographic ◽  
Medicated Feeds

Abstract A rapid, reliable separation and quantitation of zoalene (3,5-dinitroo-toluamide) from feeds is accomplished by using reverse phase liquid chromatography (LC) and ultraviolet detection. An extraction technique which is similar to the present AOAC official colorimetric method is used before chromatographic analysis. This extraction is followed by an activated alumina cleanup and LC to separate zoalene from feed matrix. The methodology was applied to a variety of spiked feed matrices, and yielded good recoveries. Liquid chromatographic results were shown to correlate with colorimetric determinations.

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