scholarly journals A direct injection method of plasma samples onto a reverse phase column for the determination of drugs.

1982 ◽  
Vol 30 (6) ◽  
pp. 2287-2290 ◽  
Author(s):  
Hisanobu Yoshida ◽  
Ikue Morita ◽  
Tsutomu Masujima ◽  
Hideo Imai
Keyword(s):  
Direct Injection ◽  
Plasma Samples ◽  
Reverse Phase ◽  
Injection Method ◽  
Reverse Phase Column ◽  
Phase Column

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 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 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%.

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.

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).

Determination of Aspirin and Salicylic Acid by Reverse-Phase Liquid Chromatography

1987 ◽  
Vol 70 (6) ◽  
pp. 964-966
Author(s):  
Dorothy R Heidemann ◽  
Edward S Schulenberg ◽  
William H Smith
Keyword(s):  
Salicylic Acid ◽  
Dosage Forms ◽  
Solid Dosage Forms ◽  
Reverse Phase ◽  
Solid Dosage ◽  
Reverse Phase Liquid Chromatography ◽  
Sample Extraction ◽  
Phase Liquid ◽  
Phase Column

Abstract Buffered solid dosage forms containing aspirin, magnesium hydroxide, and aluminum hydroxide are blended with acidic ethanol to extract the aspirin and salicylic acid rapidly. The resulting preparation is then immediately injected onto a 4.6 mm x 3 cm 5 (im reverse-phase column. Aspirin and free salicylic acid are determined simultaneously. The run time is <2 min. The total time from the initiation of sample extraction to completion of the separation is <5 min.

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