High Performance Liquid Chromatographic Analysis of Supplemental Vitamin E in Feed

1977 ◽  
Vol 60 (1) ◽  
pp. 137-139
Author(s):  
Badaruddin Shaikh ◽  
Hsinkuang S Huang ◽  
Walter L Zielinski
Keyword(s):  
Vitamin E ◽  
High Performance ◽  
High Performance Liquid Chromatographic ◽  
Peak Height ◽  
Phase Detection ◽  
Coefficients Of Variation ◽  
Supplemental Vitamin ◽  
One Step ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic

Abstract Supplemental vitamin E is extracted from feed in one step with methanol and analyzed by reverse phase partition chromatography in less than 10 min, using isocratic elution with either methanol or water-methanol as the mobile phase. Detection response (as measured by peak area) was linear between 0.5 and 3.0 μg, and the coefficients of variation for retention time and peak height on replicate analyses of the standard sample were 0.8 and 2.3%, respectively.

High Performance Liquid Chromatographic Analysis of Rotenone Formulations: Collaborative Study

1983 ◽  
Vol 66 (3) ◽  
pp. 796-800
Author(s):  
Rodney J Bushway ◽  
◽  
M J Bennett ◽  
W R Betker ◽  
R Bolduc ◽  
...  
Keyword(s):  
High Performance ◽  
Collaborative Study ◽  
High Performance Liquid Chromatographic ◽  
Peak Height ◽  
Hplc Method ◽  
Reverse Phase Hplc ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Analysis ◽  
Infrared Method ◽  
Liquid Chromatographic

Abstract A collaborative study was conducted on a high performance liquid chromatographic (HPLC) method for determining rotenone in formulations. One liquid and 4 dust samples, containing other rotenoids and pesticides, with rotenone guarantees ranging from 0.75% to 20% were analyzed by 16 laboratories. Peak height measurements were used by 14 laboratories while 8 laboratories used integrator area measurements. Samples were extracted on a rotary shaker for 1% h with dioxane. An aliquot was analyzed using reverse phase HPLC and UV detection at 280 nm. Coefficients of variation ranged from 2.47 to 3.19% for peak height determinations and from 2.56 to 6.00% for peak area determinations. One collaborator analyzed the samples by the official infrared method for a comparison. The HPLC method has been adopted official first action.

Liquid chromatographic analysis of disopyramide and its mono-N-dealkylated metabolite.

1979 ◽  
Vol 25 (3) ◽  
pp. 405-408 ◽  
Author(s):  
J J Lima
Keyword(s):  
Chromatographic Analysis ◽  
Mobile Phase ◽  
High Performance ◽  
Antiarrhythmic Drugs ◽  
Internal Standard ◽  
High Performance Liquid Chromatographic ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic ◽  
Lower Limits

Abstract We describe a rapid, sensitive, and specific "high performance" liquid chromatographic analysis for disopyramide and its mono-N-dealkylated metabolite in serum, urine, and saliva. We used a mu-Bondapak CN column and an acetate buffer mobile phase containing methanol. Retention times for the two compounds and the internal standard, p-chlorodisopyramide, were 3.4, 4.1, and 6.3 min, respectively. The lower limits of sensitivity for drug and metabolite were 50 and 80 micrograms/L, respectively, with maximum coefficients of variation of 4.6 and 12%, respectively. Currently used antiarrhythmic drugs did not interfere with the analysis of disopyramide, and the pharmacokinetics of the drug, obtained from studies of one subject, agree well with reported values.

High Performance Liquid Chromatographic Determination of α-Tocopherol in Fish Liver

1980 ◽  
Vol 63 (4) ◽  
pp. 889-893 ◽  
Author(s):  
Silas S O Hung ◽  
Young C Cho ◽  
Stanley J Slinger
Keyword(s):  
High Performance ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Peak Height ◽  
Fish Liver ◽  
Liver Sample ◽  
Liquid Chromatograph ◽  
Simple Method ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic

Abstract A simple method is described for the determinatio n of α-tocopherol in fish liver by high performance liquid chromatography. This method does not involve saponification or thin layer chromatography and thus avoids the destruction of α-tocopherol during sample preparation. The homogenized liver sample is extracted twice with dioxane–isooctane (20+80, v/v), and the combined extracts are dried under vacuum. The residue is extracted 3 times with acetonitrile from which α-tocopherol is then extracted with isooctane. The residue from the dried isooctane solution is dissolved in methanol–water (90+10, v/v) which is injected directly onto a micro Bondapak C18 high performance liquid chromatograph. The detection response to α-tocopherol at 280 nm was measured by peak height which was linear from 1 to 10 μg/25 μL injection. The coefficients of variation for retention time and peak height for 5 replicate analyses of the standard during 2 weeks were 1.4 and 2.4%, respectively. Recovery of α-tocopherol added to the sample before homogenization was 80–92% with a mean of 86.2% and a coefficient of variation of 4.9%. The minimum amount of sample and the concentration of α-tocopherol that can be accurately determined by the method are 0.5 g liver and 1 μg α-tocopherol/g liver, respectively.

High Performance Liquid Chromatography of Aflatoxins in Cottonseed Products

1977 ◽  
Vol 60 (1) ◽  
pp. 89-95 ◽  
Author(s):  
Walter A Pons ◽  
Anthony O Franz
Keyword(s):  
Silica Gel ◽  
High Performance ◽  
Methylene Chloride ◽  
High Performance Liquid Chromatographic ◽  
Peak Height ◽  
Hplc Method ◽  
Coefficients Of Variation ◽  
Water Saturated ◽  
High Degree ◽  
Liquid Chromatographic

Abstract A precise and sensitive high performance liquid chromatographic (HPLC) method is proposed for determining aflatoxins in cottonseed products in 1.0—1.5 hr. After aqueous acetone extraction, lead acetate treatment, and partition of aflatoxins into methylene chloride, sample extracts are purified on a small silica gel column requiring only 125 ml solvent/sample. Aflatoxins B1 and B2 in the purified extract are resolved on a micro particulate (10 μm) silica gel column in ca 8 min, using a water-saturated chloroform - cyclohexane - acetonitrile solvent, with detection by ultraviolet absorbance at 365 nm. The resolution was highly reproducible, giving coefficients of variation of 0.2—1.0% for retention and 1.0—2.3% for quantitation. Recovery of added aflatoxins B1 and B2 was 90— 95% at levels of 5—100 μg/kg. The within-laboratory coefficients of variation of the entire method, based on repetitive assays of a cottonseed meal (34 μg B1/kg, 6 μg B2/kg), were 7.3% (B1) and 7.4% (B3). A high degree of correlation was obtained for HPLC estimation by 2 different commercial columns; for quantitation by peak height vs. electronic integration; and for quantitation by HPLC or thin layer chromatography.

Simultaneous liquid-chromatographic analysis for 4-hydroxy-3-methoxymandelic acid and 4-hydroxy-3-methoxyphenylacetic acid in urine.

1980 ◽  
Vol 26 (2) ◽  
pp. 291-294
Author(s):  
S J Soldin ◽  
J G Hill
Keyword(s):  
High Performance ◽  
Potassium Phosphate ◽  
Amperometric Detection ◽  
Anion Exchange Chromatography ◽  
High Performance Liquid Chromatographic ◽  
Exchange Chromatography ◽  
Liquid Chromatograph ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic

Abstract We describe a rapid, reliable “high-performance" liquid-chromatographic method of simultaneously analyzing for 4-hydroxy-3-methoxymandelic acid (I) and 4-hydroxy-3-methoxyphenylacetic acid (II) in urine. Paired-ion chromatography and amperometric detection are used in the method. A 5-mL aliquot of urine is adjusted to pH 6.1 and subjected to anion-exchange chromatography (Dowex AG 1-X4, 1.8 X 0.7 cm column). The two analytes are eluted from the column with 10 mL of 3 mol/L sodium chloride, and 2 microL of the eluate, injected directly into the liquid chromatograph, is chromatographed at 40 degrees C. This column contains mu Bondapak C18, and the mobile phase is 100 mmol/L potassium phosphate buffer, pH 6.7, containing 0.5 mmol of tetrabutylammonium phosphate per liter. Detector sensitivity is 50 nA full scale. Analytical recoveries of I and II are 80--84% and 48--49%, respectively; the coefficients of variation for various concentrations in urine are about 10%.

scholarly journals Simultaneous liquid-chromatographic analysis for 4-hydroxy-3-methoxymandelic acid and 4-hydroxy-3-methoxyphenylacetic acid in urine.

1980 ◽  
Vol 26 (2) ◽  
pp. 291-294 ◽  
Author(s):  
S J Soldin ◽  
J G Hill
Keyword(s):  
High Performance ◽  
Potassium Phosphate ◽  
Amperometric Detection ◽  
Anion Exchange Chromatography ◽  
High Performance Liquid Chromatographic ◽  
Exchange Chromatography ◽  
Liquid Chromatograph ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic

Abstract We describe a rapid, reliable “high-performance" liquid-chromatographic method of simultaneously analyzing for 4-hydroxy-3-methoxymandelic acid (I) and 4-hydroxy-3-methoxyphenylacetic acid (II) in urine. Paired-ion chromatography and amperometric detection are used in the method. A 5-mL aliquot of urine is adjusted to pH 6.1 and subjected to anion-exchange chromatography (Dowex AG 1-X4, 1.8 X 0.7 cm column). The two analytes are eluted from the column with 10 mL of 3 mol/L sodium chloride, and 2 microL of the eluate, injected directly into the liquid chromatograph, is chromatographed at 40 degrees C. This column contains mu Bondapak C18, and the mobile phase is 100 mmol/L potassium phosphate buffer, pH 6.7, containing 0.5 mmol of tetrabutylammonium phosphate per liter. Detector sensitivity is 50 nA full scale. Analytical recoveries of I and II are 80--84% and 48--49%, respectively; the coefficients of variation for various concentrations in urine are about 10%.

Rapid High Performance Liquid Chromatographic Method for Determination of Gelatin-Coated Supplemental Vitamin E in Feeds

1980 ◽  
Vol 63 (5) ◽  
pp. 1154-1157
Author(s):  
Svend Eriksen
Keyword(s):  
High Performance Liquid Chromatography ◽  
Vitamin E ◽  
High Performance ◽  
Chromatographic Method ◽  
High Performance Liquid Chromatographic ◽  
Isocratic Elution ◽  
Liquid Chromatographic Method ◽  
Supplemental Vitamin ◽  
Liquid Chromatographic

Abstract A rapid method is described for determining supplemental vitamin E in feeds by means of high performance liquid chromatography (HPLC) using isocratic elution with methanol-water. The sample is mixed with water and left on a water bath to dissolve the coating. The released vitamin E is extracted, the solvent is evaporated, and the sample is redissolved in methanol for injection. The method is applicable to gelatin-coated vitamin preparations. Standard deviations for 2 ranges of supplemented vitamin E, 10–50 ppm and 50–200 ppm, are 1.6 and 5.7, respectively.

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