Liquid Chromatographic Determination of Olaquindox in Medicated Feeds and in Contents of Porcine Gastrointestinal Tract

1988 ◽  
Vol 71 (6) ◽  
pp. 1106-1109
Author(s):  
Theo J Spierenburg ◽  
Henk Van Lenthe ◽  
Gertjan De Graaf ◽  
Lowie P Jager
Keyword(s):  
Gastrointestinal Tract ◽  
Chromatographic Determination ◽  
Detector Response ◽  
Minimum Detectable Concentration ◽  
Reverse Phase ◽  
Reverse Phase Column ◽  
Liquid Chromatographic ◽  
Medicated Feeds ◽  
Phase Column

Abstract A liquid chromatographic method for the determination of olaquindox in both medicated feeds and porcine gastrointestinal tract is described. Samples are extracted with water and cleaned on a disposable reverse-phase column. The eluate is chromatographed on a reverse-phase column under isocratic conditions. Olaquindox is detected by UV absorption at 260 nm. The minimum amount detected by this method was 0.075 ng. The corresponding minimum detectable concentration in a 1 g sample was 0.3 mg/kg. The detector response was linear within the interval of 0-500 ng. Mean recovery of olaquindox in spiked gastrointestinal samples was 89 ± 5% (mean ± standard deviation, n = 43). Concentration profiles of olaquindox in the gastrointestinal tract of pigs fed medicated feed were used to evaluate the preventive potency against Treponema hyodysenteriae. The presence of some N-O reduced metabolites of olaquindox in the gastrointestinal tract was assessed

Liquid Chromatographic Determination of Sodium Fluoroacetate (Compound 1080) in Meat Baits and Formulations

1984 ◽  
Vol 67 (6) ◽  
pp. 1058-1061
Author(s):  
Harvey L Kramer
Keyword(s):  
Crown Ether ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Ultraviolet Absorbance ◽  
Reverse Phase Column ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Phase Column

Abstract A liquid chromatographic (LC) method is described for the determination of sodium fluoroacetate in meat baits and formulations. Baits were extracted with water, ultrafiltered, partitioned into butanone, back-partitioned into dilute base, and diluted with acetonitrile. Aqueous formulations of 1080 were diluted with acetonitrile. The solutions were esterified with p-bromophenacyl bromide, using crown ether catalysis, and chromatographed on a 10 μm reverse phase column. Ultraviolet absorbance was monitored at 260 nm. Samples spiked to contain 1 mg and 10 mg 1080/100 g meat gave recoveries of 84.0-103.4%.

Liquid Chromatographic Determination of Clobetasone-17-Butyrate in Ointments

1990 ◽  
Vol 73 (6) ◽  
pp. 893-895 ◽  
Author(s):  
Ajay G Patel ◽  
Ramanbhai B Patel ◽  
Mukeshbhai R Patel
Keyword(s):  
Sodium Salt ◽  
Mobile Phase ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Reverse Phase Column ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Phase Column

Abstract A liquid chromatographic (LC) method has been developed for determination of clobetasone-17-butyrate In ointment using clobetasone propionate as an internal standard. Separation was carried out on a C18 reverse-phase column using water-methanol as a mobile phase. Methylparaben and propylparaben (both sodium salt) used as preservatives did not Interfere with separation. Compounds are detected photometrically at 235 nm. Mean assay results for 0.05% commercial ointments were 100.36% (n = 5). Mean recovery of clobetasone-17-butyrate added to commercial ointment was 99.89%.

Thin Layer Chromatographic Detection and Liquid Chromatographic Determination of Stevioside and Rebaudioside A in Beverages and Foods Following Reverse Phase Column Chromatography

1986 ◽  
Vol 69 (5) ◽  
pp. 799-802
Author(s):  
Kenji Fujinuma ◽  
Kazuo Saito ◽  
Mitsuo Nakazato ◽  
Yoko Kikuchi ◽  
Akihiro Ibe ◽  
...  
Keyword(s):  
Thin Layer ◽  
Chromatographic Determination ◽  
Rebaudioside A ◽  
Reverse Phase ◽  
Reverse Phase Column ◽  
Chromatographic Procedure ◽  
Acid Reagent ◽  
Liquid Chromatographic ◽  
Phase Column

Abstract A method for the detection and determination of stevioside and rebaudioside A in beverages and foods by thin layer chromatography (TLC) and liquid chromatography (LC) is presented. Stevioside and rebaudioside A are extracted with water from a sample and purified by a reverse phase column chromatographic procedure using a silica gel 60 silanized column. The eluate from the column is concentrated to dryness, and the resulting residue is dissolved in 80% ethanol. For the detection, TLC is used, and spots of stevioside and rebaudioside A are visualized with anisaldehyde sulfuric acid reagent. Stevioside and rebaudioside A detected in samples are determined by LC with a Finepak SIL NH2 column and a mobile phase of acetonitrile-water (200 + 45) containing tetrabutylammonium phosphate, which is added to achieve the separation from some interfering compounds. Recoveries from samples spiked at 10 and 100 ppm ranged from 97.8 to 100.3% (stevioside) and 96.3 to 99.7% (rebaudioside A).

Liquid Chromatographic Determination of Zoalene in Medicated Feeds

1984 ◽  
Vol 67 (5) ◽  
pp. 861-862 ◽  
Author(s):  
John Morawski ◽  
Glenn Kyle
Keyword(s):  
Colorimetric Method ◽  
Chromatographic Determination ◽  
Activated Alumina ◽  
Reverse Phase ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Aoac Official ◽  
Liquid Chromatographic ◽  
Medicated Feeds

Abstract A rapid, reliable separation and quantitation of zoalene (3,5-dinitroo-toluamide) from feeds is accomplished by using reverse phase liquid chromatography (LC) and ultraviolet detection. An extraction technique which is similar to the present AOAC official colorimetric method is used before chromatographic analysis. This extraction is followed by an activated alumina cleanup and LC to separate zoalene from feed matrix. The methodology was applied to a variety of spiked feed matrices, and yielded good recoveries. Liquid chromatographic results were shown to correlate with colorimetric determinations.

Liquid Chromatographic Determination of Benzoyl Peroxide in Acne Preparations

1984 ◽  
Vol 67 (5) ◽  
pp. 913-915
Author(s):  
Chih-Kuang Chou ◽  
David C Locke
Keyword(s):  
Benzoyl Peroxide ◽  
Limit Of Detection ◽  
Chromatographic Determination ◽  
Detector Response ◽  
Electrochemical Detector ◽  
Reverse Phase ◽  
Order Of Magnitude ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A rapid, precise, and accurate liquid chromatographic (LC) method is described for the determination of benzoyl peroxide (BP) in acne preparations. BP is extracted from a water dispersion of the preparation with dichloromethane (DCM), and an aliquot is eluted from a C-18 reverse phase LC column with acetonitrile-O.lOM aqueous NaCI04. Selective and sensitive quantitation is accomplished with a reductive mode electrochemical detector. This detector is an order of magnitude more sensitive than a 240 nm UV absorption detector; the lower limit of detection is 2 ng for a 4 μL injection. The recovery of BP is 99.4% and the detector response is linear to at least 2 μg per 4 μL injection.

Reverse-Phase Liquid Chromatographic Determination of Paraquat and Diquat in Agricultural Products

1987 ◽  
Vol 70 (6) ◽  
pp. 1008-1011 ◽  
Author(s):  
Toshihiro Nagayama ◽  
Toshio Maki ◽  
Kimiko Kan ◽  
Mami Iida ◽  
Taichiro Nishima
Keyword(s):  
Chromatographic Determination ◽  
Agricultural Products ◽  
Minimum Detectable Concentration ◽  
Reverse Phase ◽  
Liquid Chromatographic Method ◽  
Detectable Concentration ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A simple, rapid, highly sensitive liquid chromatographic method is described for the quantitative determination of paraquat and diquat residues in agricultural products. Paraquat and diquat are extracted with hot dilute hydrochloric acid and are cleaned up on an Amberlite CG-50 column, followed by reverse-phase liquid chromatography on an NH, column, with ultraviolet detection at 257 nm (paraquat) and 310 nm (diquat). The minimum detectable concentration of both paraquat and diquat was 0.5 ng per injection, which corresponds to a lower detection limit of approximately 0.02 fjg/g in the original samples. Recoveries of paraquat and diquat added to various samples were greater than 79%, and averaged 91 and 90%, respectively, at the 0.1 and 1.0 μg/g spiking levels.

Liquid Chromatographic Determination of Propranolol Hydrochloride in Various Dosage Forms

1988 ◽  
Vol 71 (4) ◽  
pp. 761-763
Author(s):  
Carolyn S Olsen ◽  
Henry S Scroggins
Keyword(s):  
Pharmaceutical Preparations ◽  
Chromatographic Determination ◽  
Dosage Forms ◽  
Detector Response ◽  
Propranolol Hydrochloride ◽  
Reverse Phase ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A simple and rapid liquid chromatographic method is described for the determination of propranolol hydrochloride in pharmaceutical preparations. The separation was achieved on a reverse-phase octylsilane (C8) column by using a mobile phase composed of a mixture of 0.5 g dodecyl sodium sulfate in 18 mL (0.15 M) H3P04 plus 90 mL methanol, 90 mL acetonitrile, and 52 mL water. Detector response was linear for 0.03-3.1 mg/mL of propranolol. Recoveries from synthetic mixtures ranged from 99.6 to 101.7%. The results obtained by the proposed method were similar to those obtained by the USP XXI method.

Liquid Chromatographic Determination of Strychnine in Stomach Contents

1985 ◽  
Vol 68 (6) ◽  
pp. 1131-1133
Author(s):  
Jacobus J L Hoogenboom ◽  
Colin G Rammell
Keyword(s):  
Phosphoric Acid ◽  
Stomach Contents ◽  
Chromatographic Determination ◽  
Chloroform Extract ◽  
Acid Extract ◽  
Reverse Phase ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Phase Column

Abstract A chloroform extract of stomach contents at basic pH is concentrated and then extracted with 0.1M phosphoric acid. The acid extract is chromatographed on a 10 cm reverse phase column, using 0.005M phosphate buffer (pH 3.0)-acetonitrile-tetrahydrofuran (750 + 135 + 115) containing 0.01M octanesulfonic acid at a flow rate of 1.0 raL/ min for elution. Strychnine eluted in 7.3 min. Recoveries from spiked stomach contents averaged 92%. The method can be used without modification for other alkaloids.

Reverse Phase Liquid Chromatographic Determination of Vitamins D2 and D3 in Milk

1982 ◽  
Vol 65 (4) ◽  
pp. 791-797
Author(s):  
Juan F Muniz ◽  
C Timothy Wehr ◽  
H Michael Wehr
Keyword(s):  
Vitamin D ◽  
Mobile Phase ◽  
Internal Standard ◽  
Product Type ◽  
Vitamin D2 ◽  
Reverse Phase ◽  
Reverse Phase Column ◽  
Liquid Chromatographic ◽  
Phase Column

Abstract A single column reverse phase high pressure liquid chromatographic method is described for the determination of vitamins D2 and D3 in fluid milk. Resolution of vitamin D2 from D3 is helpful for use as an internal standard. The method involves overnight saponification at room temperature, extraction of unsaponifiables, precipitation of cholesterol, and aluminum oxide column cleanup. Sample extracts were chromatographed under isocratic conditions on a 10 μVydac reverse phase column using acetonitrile- methanol (90 + 10) as the mobile phase. In addition, a MicroPak MCH-5 reverse phase column with acetonitrile as the mobile phase was used with an automatic system for one product type. Thirty samples each of homogenized (3.8% fat), low fat (2.07c fat), and skim (≤0.5% fat) milk spiked with 200,400, and 600 IU vitamin D/qt were analyzed. Coefficient of variation (CV) and percent recovery for each product type and each spike level of vitamins D2 and D3 were calculated from 10 replicate analyses. Vitamin D2 recoveries for all product types at the 3 fortification levels varied from 85.2 to 99.7%; vitamin D3 recoveries varied from 85.9 to 98.8%. The minimum detectable quantity of vitamin D in milk was 15IU/qt.

Sign in / Sign up

Export Citation Format

Share Document