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.

Comparison of Gas-Liquid Chromatographic and Chemical Methods For Quantitative Determination of the Menadione and Menadione Sodium Bisulfite Content of Pharmaceutical Products

1970 ◽  
Vol 53 (5) ◽  
pp. 1093-1096
Author(s):  
A J Sheppard ◽  
W D Hubbard
Keyword(s):  
Gas Flow ◽  
Collaborative Study ◽  
Pharmaceutical Products ◽  
Sodium Bisulfite ◽  
Glycol Succinate ◽  
Separatory Funnel ◽  
Menadione Sodium Bisulfite ◽  
Coefficients Of Variation ◽  
Glass Column ◽  
Liquid Chromatographic

Abstract A collaborative study was conducted to compare the NF XII method and a GLC method for quantitatively determining menadione in pharmaceutical products. Ten collaborating laboratories analyzed 6 Pharmaceuticals encompassing tablets, capsules, and a liquid. Menadione is extracted with diethyl ether from ground tablets; slip capsules are opened and the contents are emptied into the ether along with the capsule parts. After filtration and removal of the ether, the residue is redissolved in n-hexane. The menadione sodium bisulfite injectable is transferred to a separatory funnel and extracted with chloroform and sodium hydroxide, evaporated to dryness, and redissolved in n-hexane. Menadione is chromatographed on a 6’ × 3mm id glass column packed with 1% neopentyl glycol succinate on 100–120 mesh Gas Chrom Q and operated at 135°C. The carrier gas flow is adjusted so that menadione appears within 5.5–6.5 mhi. Because of the coefficients of variation, additional study is recommended.

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.

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.

Simultaneous liquid-chromatographic determination of vitamin K1 and vitamin E in serum.

1989 ◽  
Vol 35 (12) ◽  
pp. 2285-2289 ◽  
Author(s):  
B E Cham ◽  
H P Roeser ◽  
T W Kamst
Keyword(s):  
Vitamin E ◽  
Human Serum ◽  
High Performance ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Tocopheryl Acetate ◽  
Vitamin K1 ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract We describe a high-performance liquid chromatographic procedure for the simultaneous measurement of vitamins K1 and E in human serum. Delipidated human serum (free of vitamins K1 and E) was used to make standard solutions of these vitamins, and cetyl naphthoate and alpha-tocopheryl acetate were the internal standards for vitamin K1 and vitamin E, respectively. A simple, novel separation method utilizing liquid-liquid partition chromatography was used as a preparative "clean-up" procedure. Cetyl naphthoate and vitamin K1 (after post-column reduction) were detected by fluorescence, alpha-tocopheryl acetate and vitamin E by ultraviolet absorption. Sensitivity (detection limit) of the assay was 30 pg for vitamin K1 and 5 ng for vitamin E per injection. The method is specific, precise, and more rapid than previously described procedures. Within- and between-assay CVs were 8.1% and 12.9%, respectively, for vitamin K1; 3.5% and 6.0%, respectively, for vitamin E. Analytical recoveries of vitamins K1 and E were 80% and 93%, respectively, from serum and from delipidated serum (standards). The average neonatal serum concentration of vitamin K1 was 83 ng/L, 2.5 mg/L for vitamin E; for normolipidemic adults, the values were 343 ng/L and 7.9 mg/L, respectively, and for hyperlipidemic adults, 541 ng/L and 11.1 mg/L, respectively.

Isomer Specific Assay of Ester and Salt Formulations of 2,4-Dichlorophenoxyacetic Acid by High Pressure Liquid Chromatography: Collaborative Study

1978 ◽  
Vol 61 (5) ◽  
pp. 1163-1165 ◽  
Author(s):  
Timothy S Stevens ◽  
Norman E Skelly ◽  
Robert B Grorud
Keyword(s):  
High Pressure ◽  
Collaborative Study ◽  
Internal Standard ◽  
Dichlorophenoxyacetic Acid ◽  
High Pressure Liquid Chromatographic ◽  
Coefficients Of Variation ◽  
Standard Solution ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Liquid Chromatographic

Abstract A high pressure liquid chromatographic (HPLC) assay of ester and salt formulations of 2,4-D has been collaboratively studied. The method is specific for 2,4-D isomer and resolves all known impurities from 2,4-D and the internal standard p-bromophenol. In situ saponification, at room temperature, is performed by adding a combined saponification-internal standard solution to ester products. The same saponification- internal standard solution is added to amine salts and the analytical standard. The injected aqueous potassium salt solution of 2,4-D is then converted to the acid form by an acidic buffered mobile solvent of 20% acetonitrile in water. Optimum chromatography is attained by a mobile solvent pH of 2.95 in a reverse phase microparticulate column, by ion suppression. Each of the 9 collaborators received 3 different ester and 2 different amine formulations of 2,4-D. The coefficients of variation of 2,4-D acid equivalent ranged from 1.22 to 1.59%. The method has been adopted as official first action.

High Performance Liquid Chromatographic Determination of Carbaryl Insecticide in Formulations

1980 ◽  
Vol 63 (3) ◽  
pp. 650-652
Author(s):  
William H Mcdermott
Keyword(s):  
High Performance ◽  
Methylene Chloride ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Modified Silica Gel ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A high performance liquid chromatographic method for carbaryl in formulations has been developed and used to assay 3 formulations in a 10-day repeatability study. The method uses a cyano modified silica gel column packing and a mobile phase of heptane-methylene chloride-isopropanol-methanol (60+35+4.8+0.2). The coefficients of variation for 2 wettable powders and one aqueous flowable formulation were 0.61, 0.62, and 0.75%, respectively. It is recommended that a collaborative study be conducted on this method.

Gas-Liquid Chromatographic Determination of Tetradif on Technical and Formulations: Collaborative Study

1981 ◽  
Vol 64 (4) ◽  
pp. 829-832
Author(s):  
Bram Van Rossum ◽  
Albertus Martijn ◽  
James E Launer ◽  
◽  
E C Calamita ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Flame Ionization ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract The gas-liquid chromatographic determination of tetradifon technical and formulations was collaboratively studied in duplicate with 12 laboratories. Six samples were dissolved in dichloroethane with n-hexacosane as the internal standard, chromatographed on a column of 3% SE-52, and detected by flame ionization. The average coefficients of variation were 1.2% for the 2 technical samples, 1.6% for the 2 wettable powders, and 1.5% for the 2 emulsifiable concentrates. The method has been adopted official first action.

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

1985 ◽  
Vol 68 (3) ◽  
pp. 586-589
Author(s):  
Stephen C Slahck
Keyword(s):  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Normal Phase ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Technical Products

Abstract A liquid chromatographic method for the determination of triadimefon (Bayleton™) in triadimefon technical and formulated products has been developed and subjected to a collaborative study with 7 participating collaborators. Formulations were extracted with mobile solvent and analyzed by normal phase chromatography, with 4-chlorophenyl sulfoxide as an internal standard. Collaborators were furnished with standards and samples of technical products, 50% wettable powders, and 25% wettable powders for analysis. Coefficients of variation of the values obtained on these samples were 1.42, 0.82, and 1.05%, respectively. The method has been adopted official first action.

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.

Gas-Liquid Chromatographic Method for Analysis of Pentachloronitrobenzene Formulations: Collaborative Study

1982 ◽  
Vol 65 (1) ◽  
pp. 110-114
Author(s):  
Alan R Hanks
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Peak Height ◽  
Matched Pairs ◽  
Commercial Products ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Wettable Powder ◽  
Liquid Chromatographic

Abstract A collaborative study has been conducted on a gasliquid chromatographic (GLC) method for determining pentachloronitrobenzene (PCNB) in formulations. Wettable powder, liquid, and granular matched pairs of commercial products were analyzed by 17 laboratories using peak height measurements and by 12 laboratories using integrator area measurements. Samples were dissolved in chloroform and aliquots were mixed with internal standard before GLC analysis on a 5% SE-30 column. Mean coefficients of variation for the completed study were 1.54% for integrator area measurements and 1.35% for peak height measurements. The method has been adopted official first action.

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