Improved Liquid Chromatographic Determination of Neomycin B in Bovine Kidney

1993 ◽  
Vol 76 (3) ◽  
pp. 543-548 ◽  
Author(s):  
Badar Shaikh ◽  
Jean Jackson
Keyword(s):  
Kidney Tissue ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Fluorometric Detection ◽  
Bovine Kidney ◽  
Standard Curve ◽  
Coefficients Of Variation ◽  
Neomycin B ◽  
Liquid Chromatographic

Abstract An improved liquid chromatographic (LC) method was developed for the determination of neomycin B in bovine kidney tissue. The tissue is homogenized twice in phosphate buffer; homogenate is centrifuged, and the supernatant is deproteinated by heat. The extract is acidified and mixed with ionpair concentrate, and neomycin B is determined by an LC system consisting of an ion-pairing mobile phase, a reversed-phase ODS column, postcolumn derivatization with o-phthalaldehyde reagent, and fluorometric detection. Average recoveries of neomycin B from kidney tissues spiked at 3,6, and 12 ppm were 103, 99, and 104%, with 9.7,7.9, and 3.7% intralaboratory coefficients of variation, respectively, using a standard curve prepared in buffer. The method was used to determine neomycin B in kidney tissue obtained from a calf killed 14 days after intramuscular dosing with neomycin (5 mg/lb). The tissue was found to contain about 3 ppm neomycin B. The LC conditions were also used to assay control samples of muscle, liver, milk, plasma, and urine. No interfering peaks were noted at the elution position of neomycin B.

Liquid-chromatographic determination of nadolol in plasma.

1983 ◽  
Vol 29 (6) ◽  
pp. 1085-1087 ◽  
Author(s):  
R N Gupta ◽  
R B Haynes ◽  
A G Logan ◽  
L A Macdonald ◽  
R Pickersgill ◽  
...  
Keyword(s):  
Plasma Sample ◽  
Antihypertensive Drugs ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Standard Curve ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract We describe a liquid-chromatographic procedure for determining nadolol in plasma. After an analog of nadolol is added as internal standard, the plasma sample is passed through a disposable BondElut C18 column. After several column washes, nadolol and the internal standard are eluted with methanol, and the eluate is evaporated and reconstituted with the mobile phase (acetonitrile/water, perchloric acid, and tetramethylammonium hydroxide). An aliquot of the extract is chromatographed on a non-silica resin-base reversed-phase column. The peaks are detected by fluorescence (lambda ex = 265 nm and lambda em = 305). Drug and internal standard are well resolved, and only a few extraneous peaks appear. The standard curve ranges from 10 to 400 micrograms/L. We are using this procedure to determine steady-state concentrations of nadolol in patients receiving various dosages of nadolol along with other types of antihypertensive drugs.

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.

Liquid-chromatographic determination of total hydroxyproline in urine.

1988 ◽  
Vol 34 (8) ◽  
pp. 1572-1574 ◽  
Author(s):  
C D Dawson ◽  
S Jewell ◽  
W J Driskell
Keyword(s):  
Chromatographic Determination ◽  
Reversed Phase ◽  
Normal Range ◽  
Ultraviolet Detection ◽  
Standard Curve ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Hydroxyproline Excretion ◽  
Unrestricted Diet

Abstract In this method for quantifying 4-hydroxyproline in human urine, 50 microL of urine is hydrolyzed, derivatized with phenylisothiocyanate (PITC), and then quantified by reversed-phase HPLC with ultraviolet detection. The detection limit in urine is 373 pg of hydroxyproline per 50-microL injection. The total CVs for high- and low-concentration pools are 5.3% and 3.9%, respectively (10 runs in 10 days). The standard curve of the assay is linear over a range of 0 to 22 nmol per injection. We estimated the normal range for hydroxyproline excretion in men on an unrestricted diet to be 123-308 mumol/24 h. We also report hydroxyproline concentrations in patients with metastatic bone disease and cirrhosis of the liver.

Improved liquid-chromatographic determination of propranolol in plasma, with fluorescence detection.

1979 ◽  
Vol 25 (5) ◽  
pp. 777-779 ◽  
Author(s):  
P Jatlow ◽  
W Bush ◽  
H Hochster
Keyword(s):  
Fluorescence Detection ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Back Extraction ◽  
Micro Scale ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract We describe an analysis for propranolol in plasma, with use of reversed-phase "high-pressure" liquid chromatography and fluorescence detection. Pronethalol is used as the internal standard. The procedure, which involves extraction into an organic solvent, evaporation, and clean-up by micro-scale back extraction from hexane into an aqueous phase, is specific and sensitive. The detection limit is less than 6 microgram/L (2.3 X 10(-8) mol/L). Within-day and between-day coefficients of variation are 1.8 and 4.4%, respectively. Commonly used drugs, including procainamide, N-acetylprocainamide, and quinidine, do not interfere.

Optimized liquid-chromatographic determination of metronidazole and its metabolites in plasma.

1984 ◽  
Vol 30 (5) ◽  
pp. 784-787 ◽  
Author(s):  
R A Gibson ◽  
L Lattanzio ◽  
H McGee
Keyword(s):  
Rapid Determination ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Detector Response ◽  
High Pressure Liquid Chromatographic ◽  
Liquid Chromatographic Method ◽  
Wide Range ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Metronidazole and its known metabolites in plasma can be rapidly separated by a "high-pressure" liquid-chromatographic method that can also be adapted for rapid determination of tinidazole. Samples deproteinized with trichloroacetic acid (50 g/L final concentration) undergo isocratic separation on a reversed-phase C18 column eluted with an 8/92 (by vol) mixture of acetonitrile/KH2PO4 (5 mmol/L, pH 3.0). The method is sensitive, reliably detecting as little as 25 micrograms of metronidazole and (or) its metabolites per milliliter of plasma. The detector response varied linearly with concentration for all compounds tested over a wide range (25-500 micrograms/L). Within-day and between-day variation was generally less than 2.5% for all concentrations of all compounds tested. Various other antibiotics tested did not interfere.

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