Normal-Phase Liquid Chromatographic Determination of Menadione in Animal Feeds

1988 ◽  
Vol 71 (4) ◽  
pp. 826-828 ◽  
Author(s):  
Roberto Laffi ◽  
Silvia Marchetti ◽  
Mario Marchetti
Keyword(s):  
Liquid Chromatography ◽  
Chromatographic Determination ◽  
Normal Phase ◽  
Vitamin K3 ◽  
Simple Method ◽  
Working Standard ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A simple method is presented for determination of menadione in vitamin premixes and feedstuffs by normal-phase liquid chromatography (LC). Vitamin K3 is extracted and converted to free menadione, which can be determined directly by LC analysis. Peak area or height is measured at 251 nm, and menadione is quantitated by comparison with the working standard. Menadione can be estimated with a detection limit of 2.5 ppm. Recoveries for premixes ranged from 97.3 to 98.3% and for feedstuffs from 93.7 to 96.8%. The method allows the assay of all commercial K3 compounds in pure or stabilized form and is applicable to a wide variety of feeds and premixes.

Liquid Chromatographic Determination of Fluridone Aquatic Herbicide and Its Metabolite in Fish and Crayfish

1986 ◽  
Vol 69 (5) ◽  
pp. 856-859 ◽  
Author(s):  
Sheldon D West ◽  
Edgar W Day
Keyword(s):  
Liquid Chromatography ◽  
Detection Limit ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Reverse Phase Liquid Chromatography ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Aquatic Herbicide ◽  
Liquid Chromatographic

Abstract A residue method is described for determination of the aquatic herbicide fluridone (1-methy1-3-phenyl-5-[3-(trifluoromethyl)phenyl]-4(1H)- pyridinone) and its metabolite (1-methy1-3-(4-hydroxyphenyl)-5-[3- (trifluoromethyl)phenyl]-4(1H)-pyridinone) in fish and crayfish tissues. Both compounds are extracted from tissues with methanol, and the extracts are subjected to acidic hydrolysis to release conjugated forms of fluridone and the metabolite. Sample extracts are purified by liquidliquid partitioning and Florisil Sep-Pak® column chromatography. Both compounds are separated and measured by reverse phase liquid chromatography with UV detection at 313 nm. In the absence of interfering peaks, the method has a detection limit of approximately 0.04 ppm of either compound. Overall, recoveries averaged 96% for fluridone and 78% for the metabolite for all tissue types combined.

Liquid Chromatographic Determination of Hydrocortisone in Bulk Drug Substance and Tablets: Collaborative Study

1984 ◽  
Vol 67 (2) ◽  
pp. 218-221 ◽  
Author(s):  
Milda J Walters ◽  
◽  
N Falcone ◽  
K G Hanel ◽  
E H Jefferson ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Chromatographic Determination ◽  
Normal Phase ◽  
Drug Substance ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Bulk Drug ◽  
Liquid Chromatographic

Abstract A normal phase liquid chromatographic (LC) method for determining the hydrocortisone content of bulk drug substance, tablet composites, and individual tablets was subjected to a collaborative study by 6 laboratories. The results showed a mean recovery of 98.5% for an authentic tablet formulation and reproducibility coefficients of variation of 0.97, 1.6, and 2.7% for bulk drug substance, tablet composites, and individual tablets, respectively. Infrared (IR) and thin layer chromatographic (TLC) identification tests, also included in the collaborative study, were satisfactory. The LC method for determining hydrocortisone in bulk drug substance, tablet composites, and individual tablets, with IR and TLC identification, has been adopted official first action.

Liquid-chromatographic determination of ethylene glycol in plasma.

1982 ◽  
Vol 28 (1) ◽  
pp. 32-33 ◽  
Author(s):  
R N Gupta ◽  
F Eng ◽  
M L Gupta
Keyword(s):  
Liquid Chromatography ◽  
Ethylene Glycol ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Standard Curve ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract In this novel procedure for determining ethylene glycol in plasma by liquid chromatography, benzoyl esters of ethylene glycol and of benzyl alcohol (used as the internal standard) are prepared directly in plasma. The benzoyl esters, highly ultraviolet-absorbing chromogens, are ideal compounds for analysis by reversed-phase liquid chromatography with methanol/water as the mobile phase. The benzoyl derivative of ethylene glycol is well separated from the derivative of the internal standard and from plasma constituents. The standard curve is linear to 400 mg of ethylene glycol per liter. As little as 10 mg of ethylene glycol per liter of plasma can be measured. Other commonly ingested alcohols do not interfere.

Chloramphenicol Extraction from Milk by Using the Diphasic Dialysis Method Followed by Liquid Chromatographic Determination

1994 ◽  
Vol 77 (4) ◽  
pp. 854-856 ◽  
Author(s):  
Javier Bayo ◽  
Miguel A Moreno ◽  
Javier Prieta ◽  
Susana Díaz ◽  
Guillermo Suárez ◽  
...  
Keyword(s):  
Working Conditions ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Reversed Phase Liquid Chromatography ◽  
Simple Method ◽  
Dialysis Method ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract An economical, fast, and simple method for the extraction and liquid chromatographic determination of chloramphenicol (CAP) in milk is described. CAP is extracted by using a recently developed membrane-based method named “diphasic dialysis.” CAP is detected and quantitated in the organic solvent used in dialysis without additional cleanup steps by reversed-phase liquid chromatography and UV detection (270 nm). The determination imit of CAP in milk was about 5 μg/L, although as little as 1 μg/L could be detected under optimal working conditions.

Reverse Phase High Pressure Liquid Chromatographic Determination of Arprinocid in Animal Feeds

1982 ◽  
Vol 65 (1) ◽  
pp. 43-47
Author(s):  
Virginia A Thorpe
Keyword(s):  
High Pressure ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Reverse Phase ◽  
High Pressure Liquid Chromatographic ◽  
Simple Method ◽  
Working Standard ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A simple method is presented for determination of arprinocid in finished feeds by reverse phase high pressure liquid chromatography. The sample is extracted with 95% DMF, the major feed interferences are removed by alumina chromatography, and arprinocid is separated from the remaining interferences on the HPLC column. The peak height detected at 254 nm can be quantitated by direct comparison with the working standard.

Liquid Chromatographic Determination of Bromadiolone in Rodent Baits

1990 ◽  
Vol 73 (3) ◽  
pp. 429-430
Author(s):  
Benny Koppen
Keyword(s):  
Liquid Chromatography ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Reverse Phase Liquid Chromatography ◽  
Relative Standard ◽  
Peak Areas ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A method Is described for the determination of bromadiolone in rodent bait formulations. Samples are Soxhlet-extracted using methanol as extractant and analyzed by reverse-phase liquid chromatography with UV detection at 280 nm. Chromatography is performed using a ODS-Hypersll (5 fim) column, which enables separation of the 2 diastereolsomers of bromadlolone. The sum of the peak areas of the diastereolsomers Is used for quantitation. The method was tested for precision, linearity, and recovery. Duplicate analyses of 10 formulation samples gave a mean relative standard deviation of 4.1%. Linearity was very good (correlation coefficient 0.9997) In the relevant concentration range. Recovery from spiked samples was 88.9 ±2.3%. The method is applicable to rodent bait formulations with bromadiolone content 0.005% and 0.01%.

Rapid Liquid Chromatographic Determination of Patulin in Apple Juice

1985 ◽  
Vol 68 (5) ◽  
pp. 950-951 ◽  
Author(s):  
Pedro Rafael Forbito ◽  
Norma Elena Babsky
Keyword(s):  
Liquid Chromatography ◽  
Apple Juice ◽  
Sodium Carbonate Solution ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Reverse Phase Liquid Chromatography ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A rapid method is described for the quantitative determination of patulin in apple juice. The mycotoxin is extracted from the sample with ethyl acetate and the extract is cleaned up by extraction with a sodium carbonate solution. Patulin is determined by reverse phase liquid chromatography using a μ.Bondapak C18covery is >75%.

Liquid Chromatographic Determination of Aflatoxins in Animal Feeds and Feed Components

1993 ◽  
Vol 76 (2) ◽  
pp. 366-370 ◽  
Author(s):  
Ivan Chang Yen ◽  
Keshore R Bidasee
Keyword(s):  
Liquid Chromatography ◽  
Chromatographic Determination ◽  
Chloroform Extract ◽  
Reversed Phase ◽  
Reversed Phase Liquid Chromatography ◽  
Animal Feeds ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A method is described for the determination of af latoxins B1, B2, G1, and G2 in animal feeds and feed components by liquid chromatography (LC) with fluorescence detection. In this modified procedure, the aflatoxins are extracted from the samples with methanol-water (75 + 25), and the solution is vacuum- filtered through Whatman No. 541 filter paper. An aliquot of the extract is first defatted with petroleum ether, and then the aflatoxins are partitioned into chloroform. The chloroform extract is purified on a silica gel chromatographic column, aflatoxins B1 and G1 are derivatized by trif luoroacetic acid to their hemiacetals, and the aflatoxins are determined by reversed-phase liquid chromatography. Recoveries from 11 samples ranged from 90 to 98% for aflatoxins B1 and G1 (spiking range 2-25 ng/g) and B2 and G2 (spiking range 0.2-2.5 ng/g).

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