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.

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

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.

Collaborative Study Comparing Gas-Liquid Chromatographic and Chemical Methods for Quantitatively Determining Vitamin E Content of Pharmaceutical Products

1969 ◽  
Vol 52 (3) ◽  
pp. 442-448 ◽  
Author(s):  
A J Sheppard ◽  
W D Hubbard ◽  
A R Prosser
Keyword(s):  
Vitamin E ◽  
Gas Flow ◽  
Collaborative Study ◽  
Pharmaceutical Products ◽  
Tocopheryl Acetate ◽  
Coefficients Of Variation ◽  
Tocopheryl Succinate ◽  
Glass Column ◽  
Liquid Chromatographic ◽  
Carrier Gas Flow

Abstract A collaborative study was conducted to compare the USP XVII (Emmerie-Engel) method and three GLC methods for quantitatively determining a-tocopherol, a-tocopheryl acetate, and a-tocopheryl succinate in pharmaceutical products. Nine collaborating laboratories analyzed seven pharmaceuticals encompassing tablets, capsules, and liquids. The mean coefficients of variation were: USP method, 28.6%; GLC method A, 10.2%; GLC method B, 10.8%; GLC method C, 18.0%. GLC method A was the method of choice of those evaluated. The vitamin E analogs are extracted with n-hexane from ground tablets and capsules; liquid preparations are diluted with n-hexane or injected directly onto the GLC column. The compounds are chromatographed on an 8′ × 4 mm id glass column paeked with 5% SE-30 on 100-120 mesh silanized Gas Chrom P, operated between 270-285°C, and the carrier gas flow rate adjusted so that ∝-tocopheryl acetate appears within 23-27 min. Acetic anhydride-pyridine reaction is utilized to determine whether ∝-tocopherol or ∝-tocopheryl succinate is present in a sample, since these two analogs have similar retention times. It is recommended that GLC method A be adopted as official first action.

Collaborative Study of a Fluorometric Method for Determining Selenium in Foods

1974 ◽  
Vol 57 (2) ◽  
pp. 373-378 ◽  
Author(s):  
Milan Ihnat
Keyword(s):  
Standard Deviation ◽  
Systematic Error ◽  
Collaborative Study ◽  
Bovine Liver ◽  
Standard Reference Materials ◽  
Fluorometric Method ◽  
Naturally Occurring ◽  
Coefficients Of Variation ◽  
Error Standard Deviation

Abstract A fluorometric method for the determination of selenium in foods reported previously was studied collaboratively. Nineteen laboratories reported analytical results on 10 samples representative of vegetables, cereal, dairy products, meat, and fish, and containing naturally occurring selenium. For the 5 pairs of samples, the coefficients of variation based on precision standard deviation were 2 5 . 9% at 16 ng selenium, 15.8% at 98 ng, 8.5% at 233 ng, 6.1% at 379 ng, and 4.1 % at 427 ng. The corresponding coefficients of variation computed from overall standard deviations were 65.3, 17.5, 8.9, 8.1, and 5.6%. Systematic error was significant for 2 pairs (F-test, p = 0.01), but not for the remaining 3 (p = 0.05). The ratio of the systematic error standard deviation to the precision standard deviation varied from 0.21 to 1.64. Analyses of 2 NBS standard reference materials, orchard leaves (75 ng selenium) and bovine liver (208 ng selenium), yielded results higher by 16 and 10%, respectively. The precision and accuracy of the collaborative procedure were deemed acceptable and the method has been adopted as official first action.

Lessons From the E-Ferol Tragedy

PEDIATRICS ◽  
1986 ◽  
Vol 78 (3) ◽  
pp. 503-506
Author(s):  
William F. Balistreri ◽  
Michael K. Farrell ◽  
Kevin E. Bove
Keyword(s):  
Vitamin E ◽  
Placental Transfer ◽  
Serum Vitamin ◽  
Maternal Blood ◽  
Blood Levels ◽  
Antioxidant Vitamin ◽  
Low Birth Weight Infants ◽  
Term Infants ◽  
Naturally Occurring ◽  
Supplemental Vitamin

"Those who cannot remember the past are condemned to repeat it."—G. Sabtatana Several factors combined to suggest that supplemental vitamin E should be administered to low birth weight infants. The persistent concern and controversy, the latter confounded by a paucity of data, have been discussed in recent editorials.1,2 At birh, tissue stores of the naturally occurring lipidsoluble antioxidant vitamin E (α-tocopherol) are low. The amount of total tocopherol in the tissue of premature infants is approximately one half that of full-term infants. 3 Maternal vitamin E supplementation seems to have minimal effect on serum vitamin E levels in the newborn because there is poor placental transfer; maternal blood levels are higher than cord levels.1-3

Multiresidue Gas Chromatographic Method for Determining Organochlorine Pesticides in Poultry Fat: Collaborative Study

1984 ◽  
Vol 67 (2) ◽  
pp. 284-289 ◽  
Author(s):  
James A Ault ◽  
Tim E Spurgeon ◽  
◽  
M M Anderson ◽  
R Bowers ◽  
...  
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Gel Permeation Chromatography ◽  
Accuracy And Precision ◽  
Coefficients Of Variation ◽  
Poultry Fat ◽  
Gel Permeation ◽  
Detector Method ◽  
Gas Chromatographic Method

Abstract A gas chromatographic electron capture detector method is described for the quantitative determination of organochlorine pesticide residues in poultry fat. The samples are rendered and cleaned up using automated gel permeation chromatography. The collaborative samples consisted of 10 fortified samples and one incurred residue sample, all in duplicate. Fortification levels ranged from 0.15 to 1.0 ppm for a-BHC, lindane, cis- and frans-chlordane, octachlor epoxide, o,p' and p,p'-DDT, p,p'-DDE, p,p'-TDE, hexachlorobenzene, heptachlor epoxide, dieldrin, endrin, methoxychlor, mirex, and toxaphene. The average recovery was 91.9% with a range of 81-102%. The ranges of coefficients of variation were: CVo = 3.39-14.79%; CVL = 0-16.6%; and CVx = 5.82-19.0%. The results indicate accuracy and precision comparable to other official methodology. The method has been adopted official first action.

Collaborative Study of a Semiautomated Fluorometric Method for the Determination of Reserpine in Tablets

1976 ◽  
Vol 59 (2) ◽  
pp. 289-292
Author(s):  
Mary A Kreienbaum
Keyword(s):  
Vanadium Pentoxide ◽  
Collaborative Study ◽  
Dosage Level ◽  
Fluorometric Method ◽  
Coefficients Of Variation ◽  
Semiautomated Method

Abstract A semiautomated fluorometric method for the determination of resperpine in tablets was collaboratively studied by 7 laboratories. The method is a modification of the semiautomated method of Urbányi and Stober, which involves formation of a fluorogen with vanadium pentoxide. Collaborators were supplied with 3 composites, each from a different dosage level of commercial tablets. The results obtained agreed well with the AOAC manual fluorometric method; coefficients of variation ranged from 0.45 to 2.70%. The method has been adopted as official first action.

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.

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