Simultaneous determination of haloperidol and its reduced metabolite in serum and plasma by isocratic liquid chromatography with electrochemical detection.

1983 ◽  
Vol 29 (4) ◽  
pp. 624-628 ◽  
Author(s):  
E R Korpi ◽  
B H Phelps ◽  
H Granger ◽  
W H Chang ◽  
M Linnoila ◽  
...  
Keyword(s):  
Psychiatric Patients ◽  
Internal Standard ◽  
Isoamyl Alcohol ◽  
Reversed Phase ◽  
Reduced Haloperidol ◽  
Liquid Liquid Extraction ◽  
Liquid Chromatographic Method ◽  
The Central Nervous System ◽  
Liquid Chromatographic

Abstract We describe a liquid-chromatographic method for simultaneous quantification of haloperidol and its reduced metabolite in plasma and serum. Haloperidol and reduced haloperidol are concentrated from blood samples by liquid/liquid extraction into a hexane/isoamyl alcohol mixture, with chlorohaloperidol as the internal standard. For chromatographic separation we used a reversed-phase cyano-bonded column and a mobile phase of pH 6.8 phosphate buffer/acetonitrile (55/45 by vol). Haloperidol and its reduced metabolite are detected electrochemically at +0.90 V potential between the working and reference electrodes. As little as 0.5 ng per injection is detectable. Within- and between-day CVs for determinations of haloperidol and reduced haloperidol ranged from 4 to 7% each at a concentration of 10 micrograms/L. Haloperidol concentrations measured by this method correlated well with those by gas-chromatography with nitrogen-sensitive detector and by radioimmunoassay. The present method can be used to study the effects of haloperidol on the central nervous system. It is simple enough for use in clinical laboratories that are monitoring haloperidol concentrations in the blood of psychiatric patients.

Improved liquid-chromatographic determination of haloperidol in plasma.

1984 ◽  
Vol 30 (7) ◽  
pp. 1228-1230 ◽  
Author(s):  
A K Dhar ◽  
H Kutt
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Room Temperature ◽  
Internal Standard ◽  
Isoamyl Alcohol ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract This method for determination of haloperidol in plasma is based on "high-performance" isocratic liquid chromatography with the use of a C8 bonded reversed-phase column at room temperature. Haloperidol and the internal standard (chloro-substituted analog) are extracted from alkalinized plasma into isoamyl alcohol/heptane (1.5/98.5 by vol) and back-extracted into dilute H2SO4. The aqueous phase is directly injected onto the column. The mobile phase is a 30/45/25 (by vol) mixture of phosphate buffer (16.5 mmol/L, pH 7.0), acetonitrile, and methanol. Unlike other liquid-chromatographic procedures for haloperidol, commonly used psychotropic drugs do not interfere. Analysis can be completed within an hour. The procedure is extremely sensitive (1.0 microgram/L) and is well reproducible (CV 5.6% for a 2.5 micrograms/L concentration in plasma).

Improved liquid-chromatographic method for determination of serum cortisol.

1979 ◽  
Vol 25 (7) ◽  
pp. 1293-1296 ◽  
Author(s):  
P M Kabra ◽  
L L Tsai ◽  
L J Marton
Keyword(s):  
Limit Of Detection ◽  
Internal Standard ◽  
Serum Cortisol ◽  
Peak Height ◽  
Reversed Phase ◽  
Column Temperature ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Abstract We describe a specific and precise method for measuring concentrations of cortisol in serum or plasma by liquid chromatography. Cortisol, together with an internal standard, equilenin, is extracted from 1 mL of serum or plasma and analyzed isocratically on a reversed-phase column with a mobile phase of acetonitrile/phosphate buffer (30/70, by vol.), at a flow rate of 2.0 mL/min. The eluted cortisol is detected by its absorption at 254 nm and quantitated by peak height measurements. Each analysis requires no longer than 15 min at the optimum column temperature of 50 degrees C. The lower limit of detection for cortisol is about 2 ng/sample for a standard solution; sensitivity is routinely 5 micrograms/L of serum. Analytical recoveries exceeded 95%, with good day-to-day precision (coefficients of variation between 4 and 7%). Of more than 50 drugs and steroids tested for possible interference, only the steroids cortisone, prednisone, and prednisolone may interfere with the analysis of cortisol.

Liquid-chromatographic determination of amitryptyline and its metabolites in serum, with adsorption onto glass minimized.

1982 ◽  
Vol 28 (10) ◽  
pp. 2143-2148 ◽  
Author(s):  
P M Edelbroek ◽  
E J de Haas ◽  
F A de Wolff
Keyword(s):  
High Performance ◽  
Internal Standard ◽  
Isoamyl Alcohol ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Irreversible Adsorption ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract To study correlations between the concentrations, in serum, of amitriptyline and its most important metabolites with clinical response in patients, we developed a "high-performance" liquid-chromatographic method for routine determination of amitriptyline, nortriptyline, total 10-hydroxy-amitriptyline, desmethylnortriptyline, and E(trans)- and Z(cis)-10-hydroxynortriptyline. These compounds are extracted from 1 mL of alkalinized serum into hexane/isoamyl alcohol (99/1 by vol). Perazine is the internal standard. To minimize irreversible adsorption of the drugs onto the glassware, 5 micrograms of maprotiline is added to the organic phase just before evaporation. After a 10-min resolution on a silica column eluted with acetonitrile/methanol/NH4OH (1 mol/L), absorbance is measured at 240 nm. Only chlorimipramine, doxepin, procainamide, and N-acetylprocainamide may interfere with assay of the compounds that probably are therapeutically relevant: amitriptyline, nortriptyline, and E-10-hydroxynortriptyline. Uremia, lipemia, and icterus also do not affect the analysis.

Liquid-chromatographic determination of pentobarbital in plasma with use of a resin column and an alkaline mobile phase.

1982 ◽  
Vol 28 (8) ◽  
pp. 1772-1774 ◽  
Author(s):  
R N Gupta ◽  
P T Smith ◽  
F Eng
Keyword(s):  
Mobile Phase ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Enhanced Sensitivity ◽  
Acidic Drugs ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract We describe a liquid-chromatographic method involving a new, nonsilica column (XAD-2, Hamilton Co.) for pentobarbital in plasma. Plasma is extracted with chloroform after addition of the internal standard, 5-ethyl-5-p-tolyl-barbituric acid. Acidic drugs are back-extracted into alkali, then chromatographed on the resin-base reversed-phase column. The use of alkaline mobile phase allows enhanced sensitivity and detection of barbiturates at 240 nm. The within-run CV for 10 samples was 1.9%, the between-run CV 1.8%. Ten commonly used barbiturates are separated isocratically in less than 15 min. Other commonly prescribed acidic drugs do not interfere with determination of pentobarbital.

Determination of Dicloxacillin Preparations by Liquid Chromatography

1992 ◽  
Vol 75 (1) ◽  
pp. 26-29 ◽  
Author(s):  
Mei-Chich Hsu ◽  
Yann-Jen Fann
Keyword(s):  
Internal Standard ◽  
Pharmaceutical Preparations ◽  
Standard Addition ◽  
Reversed Phase ◽  
Microbiological Method ◽  
Absorbance Detection ◽  
Liquid Chromatographic Method ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A reversed-phase liquid chromatographic method was developed for the assay of dicloxacillin In bulk drugs and pharmaceutical preparations. The samples were analyzed on a μBondapak (C18) column with a mobile phase of methanol-4% acetic acid (60 + 40) at a flow rate of 1.5 mL/mln, with UV absorbance detection at 254 nm. An equation was derived showing a linear relationship between peak area ratios of dicloxacillin to dimethylphthalate (internal standard) and the dicloxacillin concentration over a range of 2-30 μg (r = 0.9999). Standard addition recoveries ranged from 98.65 to 100.74% (mean 99.70%, n = 6). The coefficient of variation was less than 0.24%. The assay results were compared with those obtained by the official microbiological method, which indicated that the proposed method Is a suitable substitute for the microbiological method for potency assays and stability studies of dicloxacillin preparations.

scholarly journals Evaluation of Fish Decomposition by Liquid Chromatographic Assay of ATP Degradation Product

1998 ◽  
Vol 81 (3) ◽  
pp. 571-578 ◽  
Author(s):  
Michel Vallé ◽  
Pierre Malle ◽  
Stephane Bouquelet
Keyword(s):  
Chromatographic Method ◽  
Internal Standard ◽  
Correlation Coefficients ◽  
Reversed Phase ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic ◽  
Elution Gradient ◽  
Universal Measure ◽  
Phase Column

abstract A liquid chromatographic method is described for quantitative determination of nucleotide derivatives adenosine 5 -triphosphate, adenosine 5 -diphosphate, adenosine 5 -monophosphate, inosine 5 '- monophosphate, inosine, and hypoxanthine in fish. The nucleotide derivatives are extracted by grinding the flesh in cold perchloric acid, recovered, precipitated from the acid by 5M KOH, and analyzed. Nucleotide derivatives and internal standard (purine) were separated in 14 min with a new elution gradient on a reversed-phase column (Kromasil C18) at 25 C. The column was regenerated in 20 min. Regression lines gave strong correlation coefficients. This new method is fast, accurate, and more objective than the Fresh-Tester, acolorimetric determination of a ratio AC used to measure freshness. It shows that the ratio K cannot be used as a universal measure of fish decomposition.

Determination of the antidepressant fluoxetine and its metabolite norfluoxetine in serum by reversed-phase HPLC with ultraviolet detection.

1988 ◽  
Vol 34 (9) ◽  
pp. 1875-1878 ◽  
Author(s):  
P J Orsulak ◽  
J T Kenney ◽  
J R Debus ◽  
G Crowley ◽  
P D Wittman
Keyword(s):  
High Performance ◽  
Internal Standard ◽  
Reversed Phase ◽  
Liquid Extraction ◽  
Reversed Phase Hplc ◽  
Reduced Haloperidol ◽  
Ultraviolet Detection ◽  
Standard Curve ◽  
Liquid Liquid Extraction

Abstract A procedure has been developed for measuring fluoxetine and its desmethyl metabolite, norfluoxetine, in serum by reversed-phase high-performance liquid chromatography (HPLC), with ultraviolet detection at 226 nm. Fluoxetine and norfluoxetine are isolated from serum by liquid-liquid extraction. They are then separated by HPLC and quantified, with reduced haloperidol as the internal standard. Fluoxetine, norfluoxetine, and the reduced haloperidol are separated from all interfering peaks in about 15 min. The standard curve is linear (r = 1.000) for both fluoxetine and norfluoxetine concentrations over the range of 25 to 800 micrograms/L. Between-run CVs for 60 and 200 micrograms/L controls (n = 8) were 6.8 and 4.1% for fluoxetine, and 8.8 and 6.2% for norfluoxetine, respectively. In a study of 24 patients with depression who were being treated with 20-60 mg of fluoxetine per day, fluoxetine and norfluoxetine concentrations in serum, measured during the last three weeks of treatment, were 47-469 micrograms/L and 52-446 micrograms/L, respectively.

Liquid Chromatographic Determination of Thiamine, Riboflavin, and Pyridoxine in Infant Formula

1992 ◽  
Vol 75 (3) ◽  
pp. 561-565 ◽  
Author(s):  
George W Chase ◽  
William O Landen ◽  
Ronald R Eitenmiller ◽  
Abdel-Gawad M Soliman
Keyword(s):  
Internal Standard ◽  
Ammonium Hydroxide ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Acid Sodium Salt ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract An Ion pairing reversed-phase liquid chromatographic method developed for multivitamin supplements and premlxes was applied to the simultaneous determination of thiamine, riboflavin, and pyridoxine In perchloric acid extracts of milkand soy-based Infant formulas. The method uses m-hydroxy benzoic acid as Internal standard and a mobile phase consisting of water, acetonltrile, hexanesulfonlc acid sodium salt, and ammonium hydroxide solution, adjusted to pH 3.6 with phosphoric acid. The column Is a 15 cm x 3.9 mm id Nova Pak C18. Limits of detection were 0.15 μg/mL for thiamine and 0.09 μg/mL for riboflavin by UV detection at 254 nm, and 0.010 μg/mL for pyridoxine by fluorescence detection. Mean percent recoveries based on triplicate determinations were 102 ± 1.8,102 ± 3.3, and 101 ± 3.1 for thiamine, riboflavin, and pyridoxine, respectively. The results compared favorably with the AOAC methods for thiamine, riboflavin, and pyridoxine.

scholarly journals Determination of Finasteride in Tablets by High Performance Liquid Chromatography

2007 ◽  
Vol 4 (1) ◽  
pp. 109-116 ◽  
Author(s):  
K. Basavaiah ◽  
B. C. Somashekar
Keyword(s):  
High Performance ◽  
Internal Standard ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Calibration Graph ◽  
Official Method ◽  
Pharmaceutical Dosage Forms ◽  
Bulk Drug ◽  
Liquid Chromatographic

A rapid, highly sensitive high performance liquid chromatographic method has been developed for the determination of finasteride(FNS) in bulk drug and in tablets. FNS was eluted from a ODS C18reversed phase column at laboratory temperature (30 ± 2°C) with a mobile phase consisting of methanol and water (80+20) at a flow rate of 1 mL min-1with UV detection at 225 nm. The retention time was ∼ 6.1 min and each analysis took not more than 10 min. Quantitation was achieved by measurement of peak area without using any internal standard. Calibration graph was linear from 2.0 to 30 μg mL-1with limits of detection (LOD) and quantification (LOQ) being 0.2 and 0.6 μg mL-1, respectively. The method was validated according to the current ICH guidelines. Within-day co efficients of variation (CV) ranged from 0.31 to 0.69% and between-day CV were in the range 1.2-3.2%. Recovery of FNS from the pharmaceutical dosage forms ranged from 97.89 – 102.9 with CV of 1.41-4.13%. The developed method was compared with the official method for FNS determination in its tablet forms.

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