Liquid-chromatographic measurement of nitrazepam in plasma.

1982 ◽  
Vol 28 (7) ◽  
pp. 1478-1481 ◽  
Author(s):  
H Kelly ◽  
A Huggett ◽  
S Dawling
Keyword(s):  
Complete Resolution ◽  
High Performance ◽  
Internal Standard ◽  
High Performance Liquid Chromatographic ◽  
Small Sample ◽  
Ultraviolet Detector ◽  
Liquid Chromatographic Method ◽  
Chromatographic Measurement ◽  
The Stability ◽  
Liquid Chromatographic

Abstract In this simple and rapid "high-performance" liquid-chromatographic method for determining nitrazepam in plasma, serum, or whole blood, the sample at pH 7.4 is extracted into diethyl ether with an internal standard (prazepam), chromatographed, and detected at 280 nm with a fixed-wavelength ultraviolet detector. A specimen, together with standards and a quality control, can be analyzed in duplicate within 90 min. The limit of sensitivity is 5 micrograms/L (nitrazepam and 7-acetamidonitrazepam) and 50 micrograms/L (7-aminonitrazepam), and no interferents have been found. This method has the advantages of a small sample requirement and complete resolution of nitrazepam and the above-mentioned major metabolites. We have used this method for analysis of therapeutic and overdose concentrations of nitrazepam, and to investigate the stability of the drug in blood.

Liquid-chromatographic measurement of creatinine in serum and urine.

1983 ◽  
Vol 29 (5) ◽  
pp. 851-853 ◽  
Author(s):  
T Okuda ◽  
T Oie ◽  
M Nishida
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Internal Standard ◽  
High Performance Liquid Chromatographic ◽  
Liquid Chromatographic Method ◽  
External Standard ◽  
Chromatographic Measurement ◽  
Liquid Chromatographic ◽  
Serum And Urine

Abstract We describe the adaptation of a "high-performance" liquid chromatographic method for determination of creatinine in serum and urine. The proposed method is simple, rapid, precise, and accurate. The retention time for creatinine can be varied simply by changing the KH2PO4 concentration in the mobile phase: acetonitrile/aqueous KH2PO4 (1/4 by vol). Within-day precision (CV) was 1.2-3.6% in serum chromatographed with an internal standard, and 2.3-2.8% in serum when an external standard was used. Between-day precision (CV) was 1.3-2.1% in serum and 1.3-2.7% in urine (with an external standard). Analytical recoveries of creatinine added to serum were 94-100% for the method with an internal standard, 95-103% with an external standard.

Liquid-chromatographic analysis for methylphenidate (Ritalin) in serum.

1979 ◽  
Vol 25 (3) ◽  
pp. 401-404 ◽  
Author(s):  
S J Soldin ◽  
Y P Chan ◽  
B M Hill ◽  
J M Swanson
Keyword(s):  
Chromatographic Analysis ◽  
High Performance ◽  
Plasma Sample ◽  
Potassium Phosphate ◽  
Internal Standard ◽  
High Performance Liquid Chromatographic ◽  
Column Temperature ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic

Abstract We describe a "high performance" liquid chromatographic method for quantitating methylphenidate in serum. The internal standard, 4,5-diphenylimidazole, and serum or plasma sample are extracted in chloroform, evaporated, and redissolved in 20 mmol/L potassium phosphate (pH 3.5)/high-purity acetonitrile, 80/20 by vol. A centrifuged aliquot is chromatographed on mu-Bondapak C-18 with the phosphate/acetonitrile solvent as mobile phase, a flow rate of 1.6 mL/min, and a column temperature of 40 degrees C. Absorbances are read at 192 nm. This method reliably measures concentrations greater than 20 micrograms/L and has analytical recoveries of 74%.

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.

Simplified liquid-chromatographic assay of amiodarone and desethylamiodarone after solid-phase extraction.

1986 ◽  
Vol 32 (5) ◽  
pp. 890-893 ◽  
Author(s):  
P T Pollak ◽  
S G Carruthers ◽  
D J Freeman
Keyword(s):  
High Performance ◽  
Solid Phase ◽  
High Performance Liquid Chromatographic ◽  
Small Sample ◽  
Phase Method ◽  
Liquid Chromatographic Method ◽  
Solid Phase Method ◽  
Cardiovascular Medications ◽  
Liquid Chromatographic ◽  
Method Of Extraction

Abstract We describe a rapid, simplified isocratic "high-performance" liquid-chromatographic method for simultaneous measurement of the antiarrhythmic drug amiodarone and its major metabolite, desethylamiodarone, in small volumes of sera (100 microL). Compared with liquid-liquid extraction, the solid-phase method of extraction saves time and glassware and improves reproducibility for small sample volumes. Amiodarone and desethylamiodarone could be measured at concentrations as low as 250 micrograms/L. Standard curves for the drug and metabolite are linear over the range of concentrations found in our patients. Within-run CVs (n = 6) ranged from 2.7% to 4.5% for amiodarone and from 4.0% to 5.7% for desethylamiodarone over the range of 250 to 4000 micrograms/L. Between-run CVs (n = 12) were 8.3% and 5.7% for amiodarone and desethylamiodarone, respectively. Commonly used cardiovascular medications do not interfere with the assay.

scholarly journals A Rapid High-Performance Liquid Chromatographic Method for Quantitation of 5-Fluorouracil in Plasma after Continuous Intravenous Infusion

1982 ◽  
Vol 19 (2) ◽  
pp. 125-128 ◽  
Author(s):  
D C Sampson ◽  
R M Fox ◽  
M H N Tattersall ◽  
W J Hensley
Keyword(s):  
Intravenous Infusion ◽  
High Performance ◽  
Chromatographic Method ◽  
Working Hours ◽  
High Performance Liquid Chromatographic ◽  
Continuous Intravenous Infusion ◽  
Ultraviolet Detector ◽  
Liquid Chromatographic Method ◽  
Single Determination ◽  
Liquid Chromatographic

A fast, simple, precise, high-performance liquid chromatographic method for the assay of 5-fluorouracil in plasma from humans receiving continuous intravenous infusion is described. After a single extraction, underivatised 5-fluorouracil is assayed by high-performance liquid chromatography using a variable-wavelength ultraviolet detector. After extraction of 1 ml plasma, 0·3 μmol/l can be assayed. The assay is reproducible and linear up to at least 40 μmol/l. A single determination takes 3 hours and a batch of 40 specimens can be extracted and assayed in 4 working hours if automated equipment is used, enabling injections and calculations to be done overnight.

High Performance Liquid Chromatographic Analysis of Diflubenzuron and Its Formulations: Collaborative Study

1983 ◽  
Vol 66 (2) ◽  
pp. 312-316 ◽  
Author(s):  
Bram Van Rossum ◽  
Albertus Martijn ◽  
Albert A De Reijke ◽  
Jakob Zeeman ◽  
◽  
...  
Keyword(s):  
Chromatographic Analysis ◽  
High Performance ◽  
Collaborative Study ◽  
Internal Standard ◽  
High Performance Liquid Chromatographic ◽  
Water Dispersible ◽  
Liquid Chromatographic Method ◽  
Powder Samples ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic

Abstract Diflubenzuron 90% pre-concentrate and its 25% water-dispersible powder were analyzed by a high performance liquid chromatographic method. Six samples were extracted with 1,4-dioxane, linuron was added as internal standard, and diflubenzuron was separated on a 25 cm × 4.6 mm column packed with Zorbax BP-C8 with acetonitrile-water-l,4-dioxane (450 + 450 + 100) at 1.3 mL/min and monitored at 254 nm. Results were obtained from 17 laboratories. Within-laboratory repeatability was 0.6% for both the pre-concentrate and the water-dispersible powder samples and the reproducibility was 1.2%. The method has been adopted as a full CIPAC method and was adopted official first action by AOAC.

scholarly journals A New HPLC-ELSD Method for Simultaneous Determination of N-Acetylglucosamine and N-Acetylgalactosamine in Dairy Foods

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Ho Jin Kim ◽  
In Kyung Bae ◽  
Min Hee Jeong ◽  
Hye Jin Park ◽  
Jin Sil Jung ◽  
...  
Keyword(s):  
Simultaneous Determination ◽  
High Performance ◽  
High Performance Liquid Chromatographic ◽  
Dairy Foods ◽  
Light Scattering Detection ◽  
Liquid Chromatographic Method ◽  
Evaporative Light Scattering ◽  
The Stability ◽  
Liquid Chromatographic

A rapid high performance liquid chromatographic method with evaporative light scattering detection (HPLC-ELSD), using a carbohydrate column, was developed for simultaneous determination of N-acetylglucosamine (GlcNAc) and N-acetylgalactosamine (GalNAc) in dairy foods. Sample preparation was performed by precipitation using acetonitrile. The limits of detection were 2.097 mg/L for GlcNAc and 3.247 mg/L for GalNAc. The limits of quantification were 6.043 mg/L for GlcNAc and 9.125 mg/L for GalNAc. Accuracy ranged from 96.4 to 105.7% for GlcNAc and from 97.1 to 104.1% for GalNAc. The precision of the method was <1.7% for GlcNAc and <2.2% for GalNAc. The mean recovery of the method was measured by spiking samples with 30.0–120.0 mg/L GlcNAc or 12.5–50.0 mg/L GalNAc and was found to be 95.1–105.5% for GlcNAc and 99.5–105.9% for GalNAc. The stability test results of standard solutions stored at 4, 20, and 40°C were 96.2–104.7% for GlcNAc and 98.0–106.5% for GalNAc. This study determined GlcNAc and GalNAc in dairy foods using HPLC-ELSD method. This rapid, simultaneous quantitation method might be useful as a mean of convenient quality control of dairy foods.

Development and Application of HPLC Method for Clinical Pharmacokinetic Study of Domperidone

2016 ◽  
Vol 9 (6) ◽  
pp. 3531-3535
Author(s):  
Prasad Neerati ◽  
Bhargavi Latha A ◽  
Y. Shravan Kumar ◽  
Y Madhusudan Rao
Keyword(s):  
Pharmacokinetic Study ◽  
Mobile Phase ◽  
High Performance ◽  
Internal Standard ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Assay Method ◽  
Uv Detector ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

A simple and sensitive high performance liquid chromatographic method for quantification of domperidone in human serum was developed and validated. Domperi-done and internal standard (IS) propranolol hydrochloride were extracted into acetonitrile and separated using an isocratic mobile phase on a Phenomenx C18 column. The eluent was monitored by UV detector at 270 nm at a flow rate of 1.0 mL min–1. The linearity range of proposed  method was 2.5–1000 ng/ml. The intra-day and inter-day coefficient of variation and percent error values of the assay method were less than 15% and mean recovery was more than 97 and 96% for domperidone and IS, respectively. The method was found to be precise, accurate and specific during the study. The method was successfully applied for pharmacokinetic study of domperidone in humans.  

scholarly journals A Selective High Performance Liquid Chromatographic Method to Follow the Hydrolytic Degradation of Nicardipine Hydrochloride

2010 ◽  
Vol 7 (1) ◽  
pp. 85-92 ◽  
Author(s):  
K. E. Ibrahim ◽  
R. M. Al-Ashban ◽  
L. B. Babiker
Keyword(s):  
High Performance ◽  
Chromatographic Method ◽  
Degradation Products ◽  
Hydrolytic Degradation ◽  
Internal Standard ◽  
Life Time ◽  
High Performance Liquid Chromatographic ◽  
Liquid Chromatographic Method ◽  
Acetic Acid Buffer ◽  
Liquid Chromatographic

A simple, stability indicating, reverse phase high performance liquid chromatographic method was developed and validated for determination of nicardipine hydrochloride (NC) in the presence of its degradation products. The chromatographic separation was performed on Hypersil, BDS-C18, 30 cm × 3.9 mm id, at ambient temperature with UV-detection at 254 nm. A mixture of 20% (v/v) aqueous 0.01 M sodium acetate∕acetic acid buffer (pH 4.5) and 80% acetonitrile was used as the mobile phase at a flow rate of 1.5 mL min-1, losartan was used as internal standard. The calibration curve is linear over the concentration range 5-40 μg mL-1, with a regression coefficient of 0.9984 and the % recovery was 99.78±0.17. The method was used to investigate the kinetics of alkaline, acids induced degradation, effect of buffer concentration and temperature. The degradation followed first-order kinetics. The rate constant, half-life time, and activation energy were calculated

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