High-resolution gas-chromatographic determination of diacylglycerols in common vegetable oils

1993 ◽  
Vol 70 (2) ◽  
pp. 175-177 ◽  
Author(s):  
N. Frega ◽  
F. Bocci ◽  
G. Lercker
Keyword(s):  
High Resolution ◽  
Vegetable Oils ◽  
Chromatographic Determination

Add Methanolysis and Gas Chromatographic Determination of Brominated Vegetable Oils in Soft Drinks

1983 ◽  
Vol 66 (6) ◽  
pp. 1385-1389
Author(s):  
James F Lawrence ◽  
Rajinder K Chadha ◽  
Henry B S Conacher
Keyword(s):  
Vegetable Oils ◽  
Chromatographic Method ◽  
Methyl Esters ◽  
Chromatographic Determination ◽  
Soft Drinks ◽  
Packing Material ◽  
Organic Extraction ◽  
Chromatography Columns ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method has been developed for determination of brominated vegetable oils in citrus-flavored soft drinks. Oils were extracted from the drinks with ethyl ether and subjected to acidcatalyzed methanolysis. The resulting brominated methyl esters (dibromostearate, tetrabromostearate, and hexabromostearate) were separated and quantitated as single peaks on a 3% OV-3 column. Chromatography columns were stable for about 3 months of daily use; then the first 15 cm of column packing material was replaced or a new column was prepared. A number of citrus soft drinks were analyzed and contained 3.5-3.9 mg brominated oil/10 fl. oz. Recoveries from spiked samples after organic extraction and methanolysis were 94.5-105%.

High resolution gas chromatographic determination of diterpenic alcohols and sterols in coffee lipids

1995 ◽  
Vol 41 (1-2) ◽  
pp. 29-33 ◽  
Author(s):  
G. Lercker ◽  
N. Frega ◽  
F. Bocci ◽  
M. T. Rodriguez-Estrada
Keyword(s):  
High Resolution ◽  
Chromatographic Determination ◽  
Coffee Lipids

scholarly journals Liquid Chromatographic Determination of Tocopherols and Tocotrienols in Vegetable Oils, Formulated Preparations, and Biscuits

2000 ◽  
Vol 83 (3) ◽  
pp. 627-634 ◽  
Author(s):  
Josep Serra Bonvehi ◽  
Francesc Ventura Coll ◽  
Imma Alsina Rius
Keyword(s):  
Vitamin E ◽  
Vegetable Oils ◽  
Chromatographic Determination ◽  
Extraction Methods ◽  
Coefficients Of Variation ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Interday Precision

Abstract A precise and selective liquid chromatographic procedure for determining tocopherol and tocotrienol isomers in vegetable oils, formulated preparations, and biscuits was developed and validated. The proposed method quantitates vitamin E in better conditions of recoverability and reproducibility than the standard saponification procedure. Tocopherols and tocotrienols were extracted in hexane from vegetable oils, passed through a silica Sep-pak, chromatographed on a μ-Bondapak C18 column with a mobile phase of methanol–water (95 + 5, v/v), identified at 292 nm, and detected with fluorescence procedure (excitation 296 nm, and emission 330 nm). The correlation coefficient on the calibration curve was 0.9995 over the range of 0.1 to 100 μg/mL. Overall recovery of vitamin E isomers was 93%; coefficients of variation for intra- and interday precision, <2.25%. The results obtained from extraction methods 1 (with saponification) and 2 (without saponification) were compared by ANOVA test. Significant differences appeared between vitamin E isomers (p ≤ 0.05).

Liquid Chromatographic Determination of Dicofol in Kelthane Formulations: Collaborative Study

1986 ◽  
Vol 69 (4) ◽  
pp. 714-720
Author(s):  
Alan M Rothman ◽  
◽  
A Ausari ◽  
O O Bennett ◽  
E J Blusiewicz ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Standard Deviation ◽  
High Resolution ◽  
Mobile Phase ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
In Series ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method was used to determine p,p'- and o,p'-isomers of dicofol AI (active ingredient) in Kelthane® EC and MF formulations. Samples are dissolved in methanol and AI components and impurities are separated on a high resolution C8 column in series with a short C18 guard column, with a methanol-water-acetic acid mobile phase. Cleaned samples are directly injected into the LC system and are monitored at 254 nm. Twelve collaborators submitted results on 5 samples. Using 95% confidence criteria, the average total standard deviation of the total AI across all samples was 2.82%. The method has been adopted official first action.

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