Liquid Chromatographic Method for Determination of Vanillin and Related Flavor Compounds in Vanilla Extract: Collaborative Study

1989 ◽  
Vol 72 (4) ◽  
pp. 614-618
Author(s):  
Sidney Kahan
Keyword(s):  
Vanillic Acid ◽  
Chromatographic Method ◽  
Flavor Compounds ◽  
Hydroxybenzoic Acid ◽  
Method Performance ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Standard Deviations ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method for determination of vanillin, vanillic acid, p-hydroxybenzaldehyde, and p-hydroxybenzoic acid was collaboratively studied. The compounds are separated on a reversephase C-8 column using an acidic 10% methanol solvent and are detected at 254 nm. Recoveries for the 4 compounds present in vanilla extract ranged from 94 to 99%. Method performance as measured by repeatability and reproducibility standard deviations (sr and sR) and relative standard deviations (RSDr and RSDR), respectively, for determination of the 4 flavor compounds in authentic and adulterated vanilla extracts were as follows: p-hydroxybenzoic acid—sr 0.29, SR 0.39, RSDr 8.98%, RSDR 11.68%; p-hydroxybenzaldehyde—sr 0.92, sR 1.20, RSDr 6.16%, RSDR 6.95%; vanillic acid—sr 0.85, sR 1.12, RSDr 7.47%, RSDR 9.97%; vanillin—sr 7.45, sR 7.50, RSDr 3.43%, RSDR 3.48%. The method has been approved interim official first action.

Liquid Chromatographic Method for Determination of Glycerol in Wine and Grape Juice: Collaborative Study

1992 ◽  
Vol 75 (3) ◽  
pp. 379-383 ◽  
Author(s):  
Arthur Caputi ◽  
Eric Christensen ◽  
Nancy Biedenweg ◽  
Susan Miller
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Grape Juice ◽  
External Standard Method ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
External Standard ◽  
Standard Deviations ◽  
Liquid Chromatographic

Abstract An Ion-exchange liquid chromatographic method for the determination of glycerol in wine, white grape juice, and pink grape juice was collaboratively studied by 8 laboratories. Eight wine types and 12 juice samples were provided to each collaborator. Using a strong cation column, blind duplicates and standards were analyzed by an external standard method. Separate statistical evaluations were run on wine, white grape juice, and pink grape juice data. The averages of the relative standard deviations for repeatability, excluding outlying results, were 1.25% for the wine samples, 7.32% for the white grape juice samples, and 8.63% for the pink grape juice samples. The averages of the relative standard deviations for reproducibility, excluding outlying results, were 2.79% for the wine samples, 16.97% for the white grape juice samples, and 19.10% for the pink grape juice samples. The method has been adopted first action by AOAC International.

Liquid Chromatographic Method for Determination of Aflatoxins B1, B2, G1, and G2 in Corn and Peanut Products: Collaborative Study

1990 ◽  
Vol 73 (2) ◽  
pp. 260-266 ◽  
Author(s):  
Douglas L Park ◽  
Stanley Nesheim ◽  
Mary W Trucksess ◽  
Michael E Stack ◽  
Richard F Newell
Keyword(s):  
Chromatographic Method ◽  
Peanut Butter ◽  
Collaborative Study ◽  
The United States ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Standard Deviations ◽  
Contamination Levels ◽  
Liquid Chromatographic

Abstract A collaborative study of a liquid chromatographic method for the determination of aflatoxins B1, B2, G1, and G2 was conducted in laboratories located in the United States, Canada, South Africa, and Switzerland. Twenty-one artificially contaminated raw peanuts, peanut butter, and corn samples containing varying amounts of aflatoxins B1, B2, G1, and G2 were distributed to participating laboratories. The test portion was extracted with methanol-0.1N HCl ( 4 + 1 ) , filtered, defatted with hexane, and then partitioned with methylene chloride. The concentrated extract was passed through a silica gel column. Aflatoxins B1 and G1 were derivatized with trifluoroacetic acid, and the individual aflatoxins were determined by reverse-phase liquid chromatography with fluorescence detection. Statistical analysis of the data was performed to determine or confirm outliers, and to compute repeatability and reproducibility of the method. For corn, relative standard deviations for repeatability (RSDr) for anatoxin B1 ranged from 27.2 to 8.3% for contamination levels from 5 through 50 ng/g. For raw peanuts and peanut butter, RSDr values for aflatoxin Bi were 35.0 to 41.2% and 11.2 to 19.1 %, respectively, for contamination levels from 5 through 25 ng/g. RSDr values for aflatoxins B2, G1, and G2 were similar. Relative standard deviations for reproducibility (RSDR) for aflatoxin B1 ranged from 15.8 to 38.4%, 24.4 to 33.4%, and 43.9 to 54.0% for corn, peanut butter, and raw peanuts, respectively. The method has been adopted official first action for the determination of aflatoxins B1, B2, G1, and G2 in peanut butter and corn at concentrations ≥13 ng total aflatoxlns/g.

Study of the Reproducibility Characteristics of a Liquid Chromatographic Method for the Determination of Fumonisins B1 and B2 in Corn: IUPAC Collaborative Study

1993 ◽  
Vol 76 (2) ◽  
pp. 361-366 ◽  
Author(s):  
Pieter G Thiel ◽  
Eric W Sydenham ◽  
Gordon S Shephard ◽  
Dirk J Van Schalkwyk ◽  
◽  
...  
Keyword(s):  
Chromatographic Method ◽  
Fumonisin B1 ◽  
The United States ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Fumonisin B2 ◽  
Standard Deviations ◽  
Liquid Chromatographic ◽  
Fumonisins B1 And B2

Abstract An interlaboratory study of the reproducibility characteristics of a liquid chromatographic method for the determination of fumonisins B1 and B2 in corn was conducted in 11 laboratories in the United States, South Africa, Italy, Japan, United Kingdom, and The Netherlands. Each laboratory was supplied with 12 coded, blind duplicates of 6 samples of naturally contaminated corn containing different amounts of fumonisins B1 and B2 . Samples are extracted with methanol-water (3 + 1), extracts are centrifuged, and supernatants are cleaned up on strong-anion-exchange cartridges, which were supplied to participants. Solutions are derivatized with o-phthaldialdehyde, and individual fumonisins are determined by reversed-phase liquid chromatography with fluorescence detection. Quantitation is by comparison with the supplied fumonisin standards. The within-laboratory repeatability was determined by statistical analysis of data after exclusion of outliers. Relative standard deviations for within-laboratory repeatability varied from 7.7 to 25.5% for fumonisin B1 at concentrations between 200 and 2000 ng/g and from 12.5 to 36.8% for fumonisin B2 at concentrations between 70 and 740 ng/g. Relative standard deviations for betweenlaboratory reproducibility varied from 18.0 to 26.7% for fumonisin B1 and from 28.0 to 45.6% for fumonisin B2 at the concentrations mentioned above. These measures of variability indicate that the method is suitable for adoption as an official method provided that the accuracy characteristics are verified collaboratively.

scholarly journals Development and Validation of a Reversed-Phase High-Performance Liquid Chromatographic Method for the Simultaneous Determination of Amiloride Hydrochloride, Atenolol, Hydrochlorothiazide, and Chlorthalidone in Their Combined Mixtures

2009 ◽  
Vol 92 (2) ◽  
pp. 404-409 ◽  
Author(s):  
Abdalla A Elshanawane ◽  
Samia M Mostafa ◽  
Mohamed S Elgawish
Keyword(s):  
Simultaneous Determination ◽  
High Performance ◽  
Chromatographic Method ◽  
High Performance Liquid Chromatographic ◽  
Ternary Mixtures ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Liquid Chromatographic ◽  
Amiloride Hydrochloride

Abstract A high-performance liquid chromatographic method was developed for the simultaneous determination of 2 ternary mixtures containing amiloride hydrochloride, atenolol, hydrochlorothiazide, and chlorthalidone used in hypertension therapy. The use of cyanopropyl column results in satisfactory separation of both mixtures. The mobile phase consisted of 10 mM KH2PO4 buffer (pH 4.5) and methanol in a ratio of (75 25 v/v), at a flow rate of 1 mL/min. UV detector was operated at 275 nm. Calibration graphs were linear in the concentration ranges of 210, 20200, 10100, and 550 g/mL for amiloride hydrochloride, atenolol, hydrochlorothiazide, and chlorthalidone, respectively. Intraday and interday precision values (relative standard deviation) were <1.13 for mixture I (amiloride hydrochloride, atenolol, chlorthalidone), and <0.93 for mixture II (amiloride hydrochloride, atenolol, hydrochlorothiazide). The method was successfully applied for the determination of the 2 combinations in laboratory-prepared mixtures and commercial pharmaceutical formulation with high accuracy and precision. Statistical comparison of the results with those of the published methods showed excellent agreement and indicates no significant difference between them.

Collaborative Study of the Gas-Liquid Chromatographic Method for Determination of Stereochemical Composition of Amphetamine

1972 ◽  
Vol 55 (1) ◽  
pp. 146-148
Author(s):  
Clyde E Wells
Keyword(s):  
Column Chromatography ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Good Precision ◽  
Liquid Chromatographic Method ◽  
Precision And Accuracy ◽  
Standard Deviations ◽  
Liquid Chromatographic ◽  
Amphetamine Sulfate

Abstract Eight laboratories collaboratively studied a method for the quantitative GLC determination of d- and l-amphetamine in tablets. The drugs are separated from tablet excipients by column chromatography and reacted with Ntrifluoroacetyl-( 0-prolyl chloride, and the resulting derivatives are analyzed by GLC. The samples consisted of commercial d-amphetamine sulfate tablets (with and without butabarbital), dl-amphetamine sulfate tablets, and a mixed d- and l-amphetamine sulfate standard. Recoveries were acceptable, and the standard deviations never exceeded 0.64%. The results demonstrate that the method gives good precision and accuracy, and the method is recommended for adoption as official first action.

scholarly journals New Liquid Chromatographic Method for Determination of Rabeprazole Sodium in Coated Tablets

2004 ◽  
Vol 87 (4) ◽  
pp. 842-846 ◽  
Author(s):  
Cássia V Garcia ◽  
Clésio S Paim ◽  
Martin Steppe
Keyword(s):  
Quantitative Determination ◽  
Proton Pump ◽  
Chromatographic Method ◽  
Array Detector ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Validation Parameters ◽  
Rabeprazole Sodium ◽  
Liquid Chromatographic

Abstract Rabeprazole sodium is a proton pump inhibitor that covalently binds and inactivates the gastric parietal cell proton pump (H+/K+ ATPase). Little has been published about the quantitative determination of this drug. The aim of this research was to develop a new liquid chromatographic method for quantitative determination of rabeprazole in coated tablets. The system consisted of a Hypersil Keystone Betabasic C8 column (250 × 4.6 mm, 5 μm particle size), an isocratic acetonitrile–water (35 + 65) mobile phase at a flow rate of 1.0 mL/min, and a diode array detector set at 282 nm. The following validation parameters were evaluated: linearity, precision, accuracy, specificity, detection and quantitation limits, and robustness. The method showed good linearity in the concentration range of 10–70 μg/mL. The quantitation limit was 2.43 μg/mL, and the detection limit was 0.80 μg/mL. The intra- and interday precision data showed that the method has good reproducibility (relative standard deviation = 1.03). Accuracy and robustness were also evaluated, and the results were satisfactory. The mean recovery was 101.61%. The analysis of a placebo mixture demonstrated the method is also specific.

Liquid Chromatographic Method for Multiresidue Determination of Benzimidazoles in Beef Liver and Muscle: Collaborative Study

1991 ◽  
Vol 74 (3) ◽  
pp. 487-493 ◽  
Author(s):  
Leon W Levan ◽  
Charlie J Barnes
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Study Data ◽  
Beef Liver ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Repeatability And Reproducibility ◽  
Multiresidue Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method for determination of thiabendazole, 5-hydroxythiabendazole, oxfendazole, mebendazole (MBZ), and fenbendazole (FBZ) In cattle liver and muscle was collaboratively studied in 7 laboratories In 1986. For blind fortified samples containing 800 ppb FBZ, average recovery and relative standard deviations for repeatability and reproducibility (RSDr and RSDR) based on results from 6 of the participating laboratories were 83%, 12.7%, and 14.0%, respectively. Recoveries of FBZ from incurred liver samples were more variable. Recoveries of MBZ from livers fortified at the 100 ppb level were encouraging; however, the drug levels were too low in the incurred samples used for MBZ studies. Except for FBZ and MBZ In liver, the study data were not satisfactory. The method has been adopted official first action by AOAC for determination of 800-1600 ppb fenbendazole In liver. The analysis should be repeated using a smaller sample size when Initial analyses show levels greater than 1600 ppb FBZ.

Stability-Indicating Liquid Chromatographic Determination of Alpha-Ionone in Toothpaste

1988 ◽  
Vol 71 (1) ◽  
pp. 36-37
Author(s):  
Ramesh J Trivedi
Keyword(s):  
Standard Deviation ◽  
Chromatographic Method ◽  
Cost Effective ◽  
Chromatographic Determination ◽  
Average Recovery ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A simple, sensitive, and rapid liquid chromatographic method for quantitating α-ionone in toothpaste at levels of 20 ppm in the presence of large amounts of flavor has been developed. The method is accurate, precise, cost-effective, and specific for α-ionone. Average recovery of a laboratory-prepared sample was 99.0% with the relative standard deviation was 1.29% (n = 6).

Liquid Chromatographic Method for Determination of Explosives Residues in Soil: Collaborative Study

1990 ◽  
Vol 73 (4) ◽  
pp. 541-552 ◽  
Author(s):  
Christopher F Bauer ◽  
Stephan M Koza ◽  
Thomas F Jenkins
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Contaminated Soils ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Explosives Residues ◽  
Liquid Chromatographic

Abstract A collaborative study of a sonic extraction/liquid chromatographic method for determining nitroaromatic and nitramlne explosives In soil was conducted at 8 participating laboratories. Analytes HMX, RDX, TNB, DNB, tetryl, TNT, and 2,4-DNT were measured In duplicate for 4 field-contaminated soils and 4 spiked standard-matrix soils. Concentrations ranged from detection limits of about 1 μg/g to nearly 1000 μg/g. Results were evaluated with and without data Identified as outliers, which were often caused by electronic integrator miscalculation of chromatographic peak response. When outliers are excluded, method repeatability (within-laboratory relative standard deviation) for all analytes except tetryl Is less than 5% for spiked soils and less than 18% for fieldcontaminated soils. Relative standard deviation generally decreases as analyte concentration Increases. Reproducibility (between-laboratory relative standard deviation), except for tetryl and DNT, Is less than 7% for spiked soils and 26% for fleld-contamlnated soils. Thus, collaborators have nearly equivalent performance on spiked samples. For fleld-contamlnated soils, some additional Imprecision seems to result from the variability of extraction recoveries. Analyte recoveries from spiked soils are 95-97% for HMX, RDX, TNT, and DNT (similar to recoveries from aqueous samples); 92-93% for DNB and TNB; and 70% for tetryl. Poor results for tetryl (due to thermal degradation) are correctable If sonic bath temperatures are maintained near ambient. The method has been approved Interim official first action by AOAC.

scholarly journals Gradient Liquid Chromatographic Method for Determination of Chlorhexidine and Its Degradation Products in Bulk Material

1996 ◽  
Vol 79 (3) ◽  
pp. 636-639 ◽  
Author(s):  
William H Doub ◽  
Don D Ruhl ◽  
Brad Hart ◽  
Paul R Mehelic ◽  
Larry K Revelle
Keyword(s):  
Chromatographic Method ◽  
Ammonium Acetate ◽  
Degradation Products ◽  
Bulk Material ◽  
Good Precision ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Bonded Phase ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method was developed for determination of chlorhexidine and its degradation products in unformulated drug substance. A nonlinear gradient from 80% 0.1 M ammonium acetate buffer, pH 5.0, to 20% buffer over 90 min (balance is acetonitrile) is applied to a 3 μm octadecylsilane bonded-phase column. The drug and some of its degradation products are determined at 230 nm. Of 11 previously identified degradation products, 9 are determined with good precision (relative standard deviation of peak area is <2%).

Sign in / Sign up

Export Citation Format

Share Document