Gas Chromatographic Assay of Supplemental Vitamin E Acetate Concentrates: Collaborative Study

1988 ◽  
Vol 71 (6) ◽  
pp. 1168-1171 ◽  
Author(s):  
Michael P Labadie ◽  
Charles E Boufford
Keyword(s):  
Vitamin E ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Enzymatic Digestion ◽  
Tocopheryl Acetate ◽  
High Potency ◽  
Vitamin E Acetate ◽  
Supplemental Vitamin ◽  
Saponifiable Fraction

Abstract A gas chromatographic (GC) method for determination of supplemental a-tocopheryl acetate in high potency vitamin £ powders and oils was collaboratively studied as an alternative to the AOAC colorimetric method (43.147-43.151, Emmerie-Engel), which requires saponification, extraction of the saponifiable fraction, and quantitation by colorimetry. The simpler GC procedure requires only extraction and/or enzymatic digestion and dilution before quantitation. Six blind duplicates were distributed to 10 laboratories; all 10 returned results. Repeatability (sr) and reproducibility (sR), % vitamin E/g, for the feed oil concentrates was 1.1 and 1.3, respectively; for the feed adsorbates 1.0 and 1.5; and for the spray-formulated powders 1.4 and 1.3. These results compare favorably with results obtained in a comparison study of the GC and Emmerie-Engel methods conducted by BASF in 1985. The method has been approved interim official first action for determination of a-tocopheryl acetate in vitamin E acetate concentrates as an alternative for those products only to AOAC colorimetric method 43.147-43.151

Determination of Vitamin E in Foods and Feeds—A Collaborative Study

1971 ◽  
Vol 54 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Stanley R Ames
Keyword(s):  
Vitamin E ◽  
Collaborative Study ◽  
Tocopheryl Acetate ◽  
Weighted Mean ◽  
Naturally Occurring ◽  
Coefficients Of Variation ◽  
Supplemental Vitamin ◽  
Reducing Substances ◽  
Official Procedure

Abstract A collaborative study was conducted to evaluate a method for the determination of vitamin E in foods and feeds. Both the naturally occurring and the supplemental vitamin E are extracted from the sample by the appropriate procedure, the lipid residue is saponified, and α-tocopherol is isolated by TLC and determined colorimetrically. To determine supplemental a-tocopheryl acetate specifically, the sample is extracted by the appropriate procedure, reducing substances including natural atocopherol are removed by oxidative chromatography, the a-tocopheryl acetate is saponified, and the resulting a-tocopherol is determined colorimetrically. These assays for vitamin E in foods and feeds are neither rapid nor easy and considerable skill is required to obtain reliable results. Data reported by 7 collaborators on 7 samples indicate that the standard deviation among laboratories is not significant for the determination of total α-tocopherol but is significant for the determination of supplemental a-tocopheryl acetate. The weighted mean coefficients of variation were 11.0% for the determination of total a-tocopherol and 7.0% for the determination of supplemental a-tocopheryl acetate. Since an official procedure for the determination of vitamin E in foods and feeds is needed and since most laboratories were successful in carrying out the procedure, the Associate Referee recommends that the method as modified be adopted as official first action.

Comparison of Emmerie-Engel Method and Gas Chromatographic Method for Determination of Supplemental α-Tocopheryl Acetate in Feed Concentrates

1987 ◽  
Vol 70 (3) ◽  
pp. 417-419
Author(s):  
Michael P Labadie ◽  
Charles E Boufford
Keyword(s):  
Gas Chromatography ◽  
Vitamin E ◽  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Tocopheryl Acetate ◽  
High Potency ◽  
Gc Analysis ◽  
Gas Chromatographic Method ◽  
Official Procedure

Abstract The determination of supplemental a-tocopheryl acetate in high potency vitamin E powders and oils was compared using the Emmerie- Engel method and gas chromatography (GC). The Emmerie-Engel reaction requires saponification, extraction of the saponiflable fracaon, and quantitation by colorimetry. GC analysis requires only an extraction and/or dilution before quantitation. These are represented essentially by AOAC methods 43.147-43.151 (colorimetry) and 43.152-43.159 (GC) for high potency vitamin E concentrates. Each method was statistically evaluated for precision and sample-to-sample reproducibility. Each Emmerie-Engel value was divided by the GC value obtained for the same sample; an average of 1.049 with a coefficient of variation of 2.89% was obtained. It was concluded that (he GC procedure was superior to the Emmerie-Engel method, and ahould be the official procedure for determination of supplemental a-tocopheryl acetate in feed concentrates.

Colorimetric Determination of Hydroxyproline as Measure of Collagen Content in Meat and Meat Products: NMKL Collaborative Study

1990 ◽  
Vol 73 (1) ◽  
pp. 54-57 ◽  
Author(s):  
Kurt Kolar
Keyword(s):  
Collaborative Study ◽  
Colorimetric Method ◽  
Meat Products ◽  
Acid Oxidation ◽  
Colorimetric Determination ◽  
Mean Values ◽  
Collaborative Studies ◽  
Freeze Dried ◽  
Analytical Result

Abstract A colorimetric method for the determination of hydroxyproline as a measure of collagen in meat and meat products has been collaboratively studied in 18 laboratories. The method includes hydrolysis with sulfuric acid, oxidation with chloramine- T, and formation of a reddish purple complex with 4- dimethylaminobenzaldehyde. Five frozen and 3 freeze-dried samples were tested, ranging in content from 0.11 to 0.88% and from 0.39 to 4.0% hydroxyproline, respectively. The mean values of 2 identical samples were 0.245 and 0.251 %. The average recovery from a spiked sample was 96.1 %. The hydroxyproline content of a known sample (a mixture of 2 samples in the ratio 5:2) was calculated to 1.42%, which agrees well with the analytical result, 1.40%. In comparison with other collaborative studies, based on the ISO analytical method, the repeatability and reproducibility of this method agree well with the other results. This method was accepted as an official NMKL method by all national Committees, and has been adopted official first action by AOAC as an NMKLAOAC method.

Collaborative Study Using a ZDBT Colorimetric Method for the Determination of Copper in Alcoholic Products

1967 ◽  
Vol 50 (2) ◽  
pp. 334-338
Author(s):  
Duane H Strunk ◽  
A A Andreasen
Keyword(s):  
Sulfuric Acid ◽  
Carbon Tetrachloride ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Good Precision ◽  
Determination Of Copper

Abstract Results are given on a collaborative study in which a zinc dibenzyldithiocarbamate (ZDBT) colorimetric method is used to measure copper in alcoholic products such as high wine, spirits, gin, whisky, brandy, rum, and wine. In this method, the sample is made ca 0.SN with sulfuric acid, and carbon tetrachloride containing 0.2% ZDBT is added. The colored copper-ZDBT complex is extracted in the carbon tetrachloride and measured at 438 mμ against a similar carbon tetrachloride extract of a blank. Data show good precision, and it is recommended that the ZDBT method be adopted as official, first action.

Gas-Liquid Chromatographic Determination of Vitamin D2 in Multiple Vitamin Tablets Containing Minerals and Vitamin E Acetate

1974 ◽  
Vol 57 (5) ◽  
pp. 1089-1091
Author(s):  
David O Edlund ◽  
Florido A Filippini ◽  
James K Datson
Keyword(s):  
Vitamin E ◽  
Chromatographic Determination ◽  
Vitamin D2 ◽  
Vitamin E Acetate ◽  
Chromatographic Procedure ◽  
Ether Solution ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Column Chromatographic

Abstract A gas-liquid chromatographic procedure used to determine vitamin D2 in multiple vitamin tablets has been modified to make it applicable for analysis of multiple vitamin tablets containing minerals and vitamin E acetate. The procedure modifications involve pre-extraction with ether, solution in an alcoholic sulfuric acid-pyridine mixture, and column chromatographic separation on phosphate-treated alumina. The modified procedure has been statistically evaluated. A 2.2% coefficient of variation and 100.3% average recovery were obtained for the samples evaluated.

Collaborative Study of the Gas-Liquid Chromatographic Assay for Vitamin E

1972 ◽  
Vol 55 (6) ◽  
pp. 1211-1218
Author(s):  
B C Rudy ◽  
F P Mahn ◽  
B Z Senkowski ◽  
A J Sheppard ◽  
W D Hubbard
Keyword(s):  
Vitamin E ◽  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Tocopheryl Acetate ◽  
Pharmaceutical Manufacturers ◽  
Collaborative Studies ◽  
Soft Gelatin Capsules ◽  
Acid Succinate ◽  
The Mean ◽  
Liquid Chromatographic

Abstract A collaborative study for the analysis of vitamin E in multivitamin tablets was conducted and the method was subsequently approved as official first action by the AOAC. Additional data were obtained by an extensive collaborative study sponsored by the Pharmaceutical Manufacturers Association, which verified the usefulness of GLC for the assay of α-tocopherol, α-tocopheryl acetate, and α-tocopheryI acid succinate. The mean coefficient of variation obtained from the 8 participating laboratories for duplicate samples, duplicate injections, was ±2.04, 1.75, and 2.71%, respectively. Further collaborative studies were conducted on samples of mixed tocopherol concentrate, multivitamin tablets, and multivitamin soft gelatin capsules. The mean coefficient of variation obtained from 13 collaborators was in the range of ±5%. The accumulated data demonstrate the utility of this technique for improved specificity and reliability of the analysis of vitamin E.

scholarly journals Development, Optimization, and Comparison of Different Sample Pre-Treatments for Simultaneous Determination of Vitamin E and Vitamin K in Vegetables

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2509
Author(s):  
Antonella Aresta ◽  
Gualtiero Milani ◽  
Maria Lisa Clodoveo ◽  
Carlo Franchini ◽  
Pietro Cotugno ◽  
...  
Keyword(s):  
Vitamin E ◽  
Simultaneous Determination ◽  
Vitamin K ◽  
Solid Phase ◽  
Internal Standard ◽  
Premature Aging ◽  
Tocopheryl Acetate ◽  
Gas Chromatography Mass Spectrometry ◽  
Target Analytes

The absence of vitamin E from the diet can lead to cardiovascular disease, cancer, cataracts, and premature aging. Vitamin K deficiency can lead to bleeding disorders. These fat-soluble vitamins are important nutritional factors that can be determined in different methods in vegetables. In this work, the simultaneous determination of α-tocopherol, α-tocopheryl acetate, phylloquinone, and menaquinone-4 by gas chromatography–mass spectrometry (GC–MS) has been optimized using both direct injection and solid phase microextraction (SPME). Three different sample pre-treatment approaches based on: (A) solid–liquid–liquid–liquid extraction (SLE–LLE), (B) SLE, and (C) SPME were then applied to extract the target analytes from vegetables samples using menaquinone as internal standard. All the procedures allowed the determination of the target analytes in onion, carrot, celery, and curly kale samples. Similar results were obtained with the three different approaches, even if the one based on SPME offers the best performance, together with a reduced use of solvent, time consumption, and experimental complexity, which makes it the preferable option for industrial applications.

Identification of d- or di-∝-Tocopherol in Pharmaceuticals, Food Supplements, or Feed Supplements: A Collaborative Study

1975 ◽  
Vol 58 (3) ◽  
pp. 585-594
Author(s):  
Stanley R Ames ◽  
Emma-Jane E Drury
Keyword(s):  
Vitamin E ◽  
Oxidation Product ◽  
Optical Rotation ◽  
Collaborative Study ◽  
Food Supplements ◽  
Tocopheryl Acetate ◽  
Specific Optical Rotation ◽  
Feed Supplements ◽  
Before And After ◽  
Optical Rotations

Abstract A collaborative study was conducted to evaluate a method for identifying d- or dl-∝-tocopherol in pharmaceuticals, food supplements, or feed supplements. The sample is extracted and saponified, the extraneous color is removed by chromatography, and the sample is assayed for vitamin E. Optical rotations are determined before and after formation of the ferricyanide oxidation product. The specific optical rotation of the oxidation product is negligible for the dJ-form and +25.5° for the d-form. Statistical analysis of the data reported by 8 collaborators for the standard d-∝-tocopheryl acetate and for 6 unknown samples indicates a significant interaction between laboratories and samples. The mean coefficients of variation among laboratories for the determinations of the corrected specific optical rotation of the standard and the rotation ratio for the unknown samples containing d-∝-tocopherol were 11.7 and 21.6%, respectively, for all laboratories and 5.8 and 11.8%, respectively, for experienced laboratories. This identification test for vitamin E is acceptable for determining the form of vitamin E as either d or dl, but is not acceptable for accurately determining mixtures of the 2 forms. The method has been adopted as official first action for the identification of d- or dl-∝-tocopherol.

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