Liquid Chromatography with Amperometric Detection for Determining Phenolic Preservatives

1980 ◽  
Vol 63 (1) ◽  
pp. 137-142 ◽  
Author(s):  
William P King ◽  
Kuriakose T Joseph ◽  
Peter T Kissinger
Keyword(s):  
Liquid Chromatography ◽  
Propyl Gallate ◽  
Amperometric Detection ◽  
Nordihydroguaiaretic Acid ◽  
Phenolic Antioxidants ◽  
Phase System ◽  
Reverse Phase ◽  
Tert Butyl ◽  
Sensitive Method

Abstract Liquid chromatography with amperometric detection is a rapid and sensitive method for determining commonly encountered phenolic antioxidants including 3(2)-tert-butyl-4-hydroxyanisole, tert-butylhydroquinone, n-propyl gallate, nordihydroguaiaretic acid, and 2,6-di-tert-butyl-4-hydroxymethylphenol (Ionox-100), and the antimicrobial parabens, in a variety of commercial products. Sample extracts are chromatographed directly with few interferences on the reverse phase system. The typical linear range extends from 10−11 to 10−6 mole of injected analyte. Pertinent experimental factors are discussed with regard to the requirements of the detector and optimizing the determination of this class of compounds

Simultaneous Analysis of Nivalenol and Deoxynivalenol in Cereals by Liquid Chromatography

1987 ◽  
Vol 70 (3) ◽  
pp. 479-483 ◽  
Author(s):  
Denis R Lauren ◽  
Roy Greenhalgh
Keyword(s):  
Liquid Chromatography ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Reverse Phase ◽  
Reverse Phase Liquid Chromatography ◽  
Relative Standard ◽  
Phase Liquid ◽  
Cereal Samples ◽  
Sensitive Method

Abstract A sensitive method is described for determination of nivalenol (NIV) and deoxynivalenol (DON) in cereals by using reverse phase liquid chromatography and UV detection at 222 nm. The sample is extracted with acetonitrile-water (85 + 15) and an aliquot is purified by passage through a combined column of cation exchange resin and alumina-carbon (20 + 1). Analysis at this stage is possible with some samples but the method recommends passing an aliquot through a carbon minicolumn after evaporation and solubilization in methanol. Interference from coextracted compounds at this point is negligible. Recoveries of both NIV and DON from spiked extracts taken through the full method were in the range 83-94%. The relative standard deviation, based on 5 replicate determinations from each of 2 corn samples, was approximately 5% for both NIV and DON. With a 10 fiL injection, the minimum contamination (3 x signal/noise ratio) able to be detected in cereal samples was about 0.015 μ NIV/g and 0.05 μ DON/g. The cleaned up extracts are also suitable for analysis by gas chromatography.

Liquid Chromatographic Determination of Ivermectin in Bovine Serum

1989 ◽  
Vol 72 (1) ◽  
pp. 59-59 ◽  
Author(s):  
Delbert D Oehler ◽  
J Allen Miller
Keyword(s):  
Liquid Chromatography ◽  
Bovine Serum ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Sensitive Method

Abstract A rapid, sensitive method is described for the determination of ivermectin concentrations in bovine serum. Ivermectin is extracted by passing a sample through a reverse-phase C18 cartridge. A silicapacked cartridge is used to purify the extract further. Ivermectin is quantitated by liquid chromatography with detection at 245 nm. Recoveries were 95 ± 4% for samples fortified with 20 ppb ivermectin. Concentrations as low as 2 ppb can be detected in 5 g samples.

Fluorimetric Determination of Anatoxin M1 in Cheese

1987 ◽  
Vol 70 (3) ◽  
pp. 472-475
Author(s):  
Jan P Bijl ◽  
Carlos H Van Peteghem ◽  
Diana A Dekeyser
Keyword(s):  
Liquid Chromatography ◽  
Final Analysis ◽  
Fluorimetric Determination ◽  
Reverse Phase ◽  
Cheese Sample ◽  
Acetone Water ◽  
Silica Cartridge ◽  
Layer Chromatography ◽  
Sensitive Method

Abstract A simple and sensitive method is proposed for the determination of aflatoxin M, in cheese. The ground cheese sample is extracted with acetone-water (3 + 1). Acetone is evaporated under vacuum, and the aqueous phase is passed through a C18 disposable cartridge. After the cartridge is washed with acetonitrile-water (1 + 9), the toxin is eluted with acetonitrile. The extract is then cleaned up on a silica cartridge. Final analysis is performed by 2-dimensional thin layer chromatography (TLC) combined with fluorodensitometry or by liquid chromatography on a reverse phase C„ column with fluorescence detection. Recovery is greater than 90%, and the coefficient of variation is 6% or less. The detection limit is in the range of 10 ng/kg. The identity of aflatoxin M2, is confirmed by formation of the Mu or acetyl-M1, derivative and rechromatography.

High Performance Liquid Chromatographic Determination of Nine Phenolic Antioxidants in Oils, Lards, and Shortenings

1979 ◽  
Vol 62 (6) ◽  
pp. 1239-1246 ◽  
Author(s):  
B Denis Page
Keyword(s):  
High Performance ◽  
Nordihydroguaiaretic Acid ◽  
Chromatographic Determination ◽  
Gradient Elution ◽  
High Performance Liquid Chromatographic ◽  
Phenolic Antioxidants ◽  
Phase Gradient ◽  
Tert Butyl ◽  
Dodecyl Gallate

Abstract A simple, rapid technique is described for the determination of 2- and 3-tert-butyl-4-hydroxyanisole (BHA), tert-butylhydroquinone (TBHQ), 3,5-di-tert-butyl-4-hydroxytoluene (BHT), 2,6-di-tert-butyl-4-hydroxymethylphenol (Ionox-100), 2,4,5-trihydroxybutyrophenone (THBP), propyl gallate (PG), octyl gallate (OG), dodecyl gallate (DG), and nordihydroguaiaretic acid (NDGA) in vegetable oils, lards, and shortenings. The antioxidants are partitioned from hexane-oil into acetonitrile, concentrated under vacuum, and determined by reverse phase, gradient elution, high performance liquid chromatography with detection at 280 nm. The mobile phase is wateracetonitrile with 5% acetic acid. With this system, only Ionox-100 and OG are not resolved. Recoveries from soya-sunflower seed oil spiked at 16 and 100 ppm and from lard at 32 ppm for 8 of the 9 antioxidants ranged from 96 to 103%, 100 to 102%, and 98 to 102%, respectively. The recoveries of BHT, due to incomplete extraction, were 84, 85, and 87%, respectively.

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