HPLC measurement of chlorophenoxy herbicides, bromoxynil, and ioxynil, in biological specimens to aid diagnosis of acute poisoning.

1989 ◽  
Vol 35 (7) ◽  
pp. 1342-1347 ◽  
Author(s):  
R J Flanagan ◽  
M Ruprah
Keyword(s):  
Whole Blood ◽  
High Performance ◽  
Limit Of Detection ◽  
Internal Standard ◽  
High Performance Liquid Chromatographic ◽  
Acute Poisoning ◽  
Tissue Homogenate ◽  
Chlorophenoxy Herbicides ◽  
Liquid Chromatographic ◽  
Potassium Dihydrogen Orthophosphate

Abstract A simple high-performance liquid-chromatographic assay for eight chlorophenoxy (2,4-D and related compounds) and two benzonitrile (bromoxynil and ioxynil) herbicides has been developed to aid in the diagnosis of acute poisoning. Sample (whole blood, plasma/serum, urine, or tissue homogenate) or standard (100 microL) is vortex-mixed (ca. 5 s) with 20 microL of internal standard solution [1.00 g/L 2,4,5-TP in 0.02 mol/L Tris buffer, pH 9.6:methanol (1 + 1)]. Dilute (0.2 mL/L) hydrochloric acid in methanol, 200 microL, is added and the mixture is again vortex-mixed (30 s). After centrifugation (9950 X g, 2 min) a 10-20 microL portion of the supernate is analyzed on a 250 X 5 mm (i.d.) Spherisorb S5 Phenyl column, with aqueous potassium dihydrogen orthophosphate (50 mmol/L, pH 3.5) and acetonitrile (3 to 1 by vol) at a flow-rate of 1.8 mL/min as eluent. The method is capable of resolving the chlorophenoxy/benzonitrile mixtures (2,4-D/MCPP, 2,4-D/DCPP, 2,4-D/ioxynil, 2,4-D/MCPP/DCPP, 2,4-D/2,4,5-T, and MCPP/ioxynil) encountered in the U.K. The limit of detection (at 240 nm) is 20 mg/L (10 mg/L for bromoxynil and ioxynil). Intra-assay and interassay CVs were less than 5% and less than 8%, respectively, for all analytes. Plasma:whole blood distribution ratios ranged from ca. 1.7 for 2,4-DB to ca. 2.0 for 2,4-D, emphasizing that results of whole-blood measurements must be multiplied by a factor of ca. 2 for comparison with plasma/serum data.

Identification and analysis of nine metabolites of cyclosporine in whole blood by liquid chromatography. 1: Purification of analytical standards and optimization of the assay.

1987 ◽  
Vol 33 (10) ◽  
pp. 1841-1850 ◽  
Author(s):  
G L Lensmeyer ◽  
D A Wiebe ◽  
I H Carlson
Keyword(s):  
Whole Blood ◽  
High Performance ◽  
Solid Phase ◽  
Internal Standard ◽  
High Performance Liquid Chromatographic ◽  
Cross Reactivity ◽  
Human Bile ◽  
Analytical Recovery ◽  
Liquid Chromatographic ◽  
Analytical Standards

Abstract We describe an extraction and an isocratic "high-performance" liquid-chromatographic (HPLC) separation of cyclosporine (CsA) and nine metabolites (M1, M8, M17, M18, M21, M25, M26, M203-218, and MUNDF1) from whole blood. Metabolites (for standards) were purified from human bile with liquid-liquid and solid-phase extractions, chromatographed on a cyanopropyl (CN) semipreparative HPLC column, and further purified on octyl, CN, and silica columns. The identity of each metabolite was verified with authentic standards on three chemically different HPLC columns and on the basis of cross-reactivity data from radioimmunoassay. For the routine analytical method, 1 mL of whole blood is diluted, hemolyzed, and applied to a Bond Elut CN (500 mg) cartridge to extract CsA, metabolites, and cyclosporin C, the internal standard. Interferences are removed by using four wash solutions and an additional cartridge of octyldecyl sorbent introduced prior to elution. Analytes are separated on a Zorbax CN analytical column maintained at 58 degrees C, with detection at 214 nm. Analytical recovery, as tested with three lots of CN sorbent, ranged from 47% to 95% for the 10 cyclosporines. Between-run CVs are less than 10% at 200 micrograms/L (concentration of each compound) and the standard curves are linear to 1500 micrograms/L. We also report a study of the separation mechanisms.

Improved liquid-chromatographic determination of cyclosporine, with concomitant detection of a cell-bound metabolite.

1985 ◽  
Vol 31 (2) ◽  
pp. 196-201 ◽  
Author(s):  
G L Lensmeyer ◽  
B L Fields
Keyword(s):  
Whole Blood ◽  
High Performance ◽  
Solid Phase ◽  
Internal Standard ◽  
Correlation Coefficients ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Standard Curve ◽  
A Cell ◽  
Liquid Chromatographic

Abstract This unique extraction and isocratic "high-performance" liquid chromatographic method for measuring cyclosporine (CsA) in blood involves a Zorbax cyanopropyl analytical column maintained at 58 degrees C, with detection at 214 nm, and recycling of the water:acetonitrile mobile phase for improved long-term column stability and efficiency. Routinely, 1.0 mL of serum, plasma, or whole blood is diluted with water:acetonitrile (70:30) and applied to a disposable solid-phase cyanopropyl column to rapidly extract the drug and the internal standard cyclosporin D (CsD). Analytical recovery for this step averages 90% with whole blood and 98% with serum and plasma. Between-run CVs were 6.5 and 2.6% for means of 104 and 1128 micrograms/L, respectively. The standard curve is linear up to 1600 micrograms/L. The minimum detection limit is 10 to 15 micrograms/L. No interferences from endogenous substances or other drugs were found. In addition, a compound cross reacting with the Sandoz radioimmunoassay antibody was isolated from patients' samples with the present procedure and was tentatively identified as a CsA metabolite(s). It appears to be highly partitioned on blood cells, very little being detected in the serum or plasma. In a comparison with RIA, correlation coefficients were 0.828 and 0.652 for serum and whole blood, respectively. Results from a 12-h pharmacokinetic study in which different sample types were analyzed by RIA and liquid chromatography further exemplified major discrepancies between types of CsA determinations.

Liquid-chromatographic determination of alpha- and gamma-tocopherols in erythrocytes, with fluorescence detection.

1983 ◽  
Vol 29 (10) ◽  
pp. 1840-1842 ◽  
Author(s):  
J Lehmann ◽  
H L Martin
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract We have adapted to erythrocytes a method for the determination of alpha- and gamma-tocopherols in plasma and platelets. Erythrocytes (50 microL) were extracted with methanol containing tocol (internal standard) and pyrogallol. Tocopherols were partitioned into chloroform, washed, and injected in methanol onto a reversed-phase (C18) "high-performance" liquid-chromatographic column. The mobile phase was methanol/water (99/1 by vol) at a flow rate of 2 mL/min and detection was with a "high-performance" spectrophotofluorometer. The limit of detection for either tocopherol is 0.10 microgram/mL of packed cells. Analytical recoveries ranged from 93 to 104%. Some values for tocopherols in human erythrocytes are presented.

High Performance Liquid Chromatographic Determination of Dothiepin and Northiaden in Human Plasma and Serum

1973 ◽  
Vol 1 (2) ◽  
pp. 387-390 ◽  
Author(s):  
R R Brodie ◽  
L F Chasseaud ◽  
E L Crampton ◽  
D R Hawkins ◽  
P C Risdall
Keyword(s):  
Human Plasma ◽  
High Performance ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Related Drug ◽  
Liquid Chromatographic Determination ◽  
The Mean ◽  
Liquid Chromatographic

A method has been developed for the separation and measurement of dothiepin and the N-desmethyl metabolite, northiaden, in human plasma or serum by high performance liquid chromatography. The method uses a structurally-related drug, amitriptyline, as an internal standard and provides a limit of detection of about 10 ng/ml for each component. At a concentration of 20 ng/ml, northiaden and dothiepin could be measured within ±11% and ± 6% of the mean respectively and at 200 ng/ml within ± 3% and ± 1% of the mean. The method has been applied to the analysis of serum from patients undergoing dothiepin therapy.

Specific and Sensitive Measurement of FK506 and Its Metabolites in Blood and Urine of Liver-Graft Recipients

1992 ◽  
Vol 38 (10) ◽  
pp. 2025-2032 ◽  
Author(s):  
U Christians ◽  
F Braun ◽  
M Schmidt ◽  
N Kosian ◽  
H M Schiebel ◽  
...  
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Particle Beam ◽  
Gradient Elution ◽  
High Performance Liquid Chromatographic ◽  
Liver Graft ◽  
Limit Of Quantification ◽  
Solid Liquid ◽  
Liquid Chromatographic

Abstract A specific and sensitive assay for quantifying the immunosuppressant FK506 and its metabolites in blood and urine was developed. 32-O-Acetyl FK506 was synthesized and used as internal standard. FK506 and its metabolites were purified from the samples by solid-liquid extraction and were injected into a high-performance liquid chromatographic (HPLC) system linked to a mass spectrometer (MS) by particle-beam interface. The FK506 derivatives were separated from interfering material by use of a 100 x 4 mm C8 analytical column and water/acetonitrile or water/methanol gradient elution; they were detected by negative chemical ionization with methane as reagent gas. The limit of detection was 25 pg in a standard solution, and the limit of quantification in blood was 250 pg (extracted from 1 mL of blood). The CV was 11.3% at 5 ng, and no interferences with other drugs were found.

High Performance Liquid Chromatographic Determination of Bendiocarb on Wool

1980 ◽  
Vol 63 (1) ◽  
pp. 47-48
Author(s):  
James M Zehner ◽  
Richard A Simonaitis ◽  
Roy E Bry
Keyword(s):  
Standard Deviation ◽  
High Performance ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Uv Detector ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A high performance liquid chromotographic method is presented for determining bendiocarb (2,2-dimethyl-1,3-benzodioxol-4-yl methylcarbamate) on wool. Bendiocarb is extracted from wool with methanol containing methyl benzoate as internal standard, eluted through a Zorbax ODS column with methanol-water (55 + 45), and detected with a UV detector at 280 nm. The method can be used to determine bendiocarb at 0.001–0.02% by weight. The limit of detection is 0.0004%, or 4 ppm. At 4 analyses each, recovery at 0.013% was 101%, standard deviation 2.8%; at 0.003%, recovery was 96%, standard deviation 5.6%; at 0.001%, recovery was 103%, standard deviation 2.9%.

A Rapid High-Performance Liquid-Chromatographic Method for Simultaneously Determining the Concentrations of TFM and Bayer 73 in Water During Lampricide Treatments

1982 ◽  
Vol 39 (5) ◽  
pp. 778-782 ◽  
Author(s):  
V. K. Dawson
Keyword(s):  
High Performance ◽  
Small Volume ◽  
Methanol Extract ◽  
Limit Of Detection ◽  
Internal Standard ◽  
High Performance Liquid Chromatographic ◽  
Ultraviolet Spectrophotometry ◽  
Reverse Phase ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

The high-performance liquid-chromatography (HPLC) procedure requires only minutes per sample, is specific, and is relatively sensitive (limit of detection < 0.005 mg/L for both chemicals). A combined buffer (pH 4) and internal standard (3-chlorodiphenylamine) reagent is added to the water sample, which is injected through a Sep Pak C18 disposable cartridge. The cartridge adsorbs and retains both the lampricides and the internal standard. The quantitative elution of the three chemicals from the cartridge with a small volume of methanol effectively concentrates the sample and provides sample cleanup. The methanol extract is then analyzed directly by HPLC on an MCH 10 reverse phase column by using a methanol:0.01 mol/L acetate buffer (87:13, v:v) as the mobile phase at 2 mL/min and detected by ultraviolet spectrophotometry at 330 (or 254) nm. A microprocessor data system further facilitates the procedure by quantifying off-scale peaks and yielding results directly in units of concentration (mg/L).Key words: sea lamprey, lampricides, methodology, chromatographic techniques, 3-trifluoromethyl-4-nitrophenol, 2′,5-dichloro-4′-nitrosalicylanilide, streams

scholarly journals A Simple and Sensitive HPLC Method for Simultaneous Analysis of Nabumetone and Paracetamol in Pharmaceutical Formulations

2011 ◽  
Vol 8 (s1) ◽  
pp. S41-S46
Author(s):  
Prafulla Kumar Sahu ◽  
M. Mathrusri Annapurna ◽  
Dillipkumar Sahoo
Keyword(s):  
High Performance ◽  
Internal Standard ◽  
Pharmaceutical Formulations ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Simultaneous Estimation ◽  
Aqueous Acetic Acid ◽  
Linear Calibration ◽  
Acceptance Range ◽  
Liquid Chromatographic

This paper describes a high-performance liquid chromatographic method for simultaneous estimation of nabumetone and paracetamol in binary mixture. The method was based on RP-HPLC separation and quantitation of the two drugs on hypersil C-18 column (250 mm × 4.6 mm) using a mobile phase consisting of acetonitrile and 0.05% aqueous acetic acid (70:30v/v) at flow rate of 1 mL min-1. Quantitation was achieved with PDA detector at 238 nm based on peak area with linear calibration curves at concentration ranges 5-25 µg mL-1for both the drugs. Naproxen sodium was used as internal standard. The method has been successively applied to pharmaceutical formulation. No chromatographic interference from the tablet excipients was found. The method was validated in terms of precision, robustness, recovery and limits of detection and quantitation. The intra and inter-day precision and accuracy values were in the acceptance range as per ICH guidelines.

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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