Liquid Chromatographic Determination of Fumonisins with 4-Fluoro-7-nitrobenzofurazan

1992 ◽  
Vol 75 (5) ◽  
pp. 829-833 ◽  
Author(s):  
Peter M Scott ◽  
Guillaume A Lawrence
Keyword(s):  
Limit Of Detection ◽  
Potassium Cyanide ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Dihydrogen Phosphate ◽  
Corn Meal ◽  
Sodium Dihydrogen Phosphate ◽  
Corn Flakes ◽  
Ground Corn ◽  
Fumonisins B1 And B2

Abstract Fumonisins B1 and B2 are closely related mycotoxins produced by Fusarium moniliforme, F. proliferatum, and related species. Disadvantages of 2 fluorescence derivatizing reagents currently used for liquid chromatography (LC) are instability of the derivatives (with o-phthaldialdehyde-mercaptoethanol) and formation of 2 peaks (with fluorescamine). 4-Fluoro-7-nitrobenzofurazan (4-fluoro-7- nitrobenz-2-oxa-1,3-diazole; NBD-F) was, therefore, investigated. Although a larger molar excess of this reagent is required for fumonisins than for amino acids, the derivatives formed are moderately stable, and as little as 1 ng fumonisins B1 or B2 can be detected, with a linear response up to at least 50 ng injected. Reversed-phase LC (C18 column) was carried out with a mobile phase of methanol- 0.05M sodium dihydrogen phosphate adjusted to pH 5 (1 -1-1), which was mixed with an equal volume of acetonitrile-water (8 + 2) after 5 min. Using a modification of a strong anion exchange cleanup procedure, good recoveries (averages of 94 and 80%, respectively) of fumonisins B1 and B2 from ground corn, corn meal, and corn flakes in the 125̶ 5000 ng/g range were generally obtained; the limit of detection of the overall method was about100 ng/g. Similar results were obtained in studies with ground corn, corn meal, and corn flakes using naphthalene-2,3-dicarboxaldehyde-potassium cyanide (NDA-KCN) for derivatization; average recoveries of fumonisins B1 and B2 were 94 and 83%, respectively.

Determination of Sulfamethazine in Bovine and Porcine Tissues by Reversed-Phase Liquid Chromatography

1994 ◽  
Vol 77 (3) ◽  
pp. 558-564 ◽  
Author(s):  
Joe O K Boison ◽  
Lily J-Y Keng
Keyword(s):  
Internal Standard ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Dihydrogen Phosphate ◽  
Sodium Dihydrogen Phosphate ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic ◽  
Layer Chromatography

Abstract A simple, sensitive, and rapid method for the liquid chromatographic determination of sulfamethazine in animal tissues was developed by using sulfaethoxypyridazine as the internal standard. Homogenized tissue is extracted with chloroform, and the sulfa drugs are back-extracted from chloroform into alkaline sodium chloride solution. The pH of the aqueous extract is adjusted to 6, and the sulfas are concentrated on a conditioned C18 cartridge and eluted with 1 mL methanol. Sulfamethazine and sulfaethoxypyridazine are separated from tissue co-extractives by reversed-phase chromatography on a C18 column by using 0.05M sodium dihydrogen phosphate-methanol (7 + 3). Detection is performed at 265 nm. The method has a detection limit of 2 ng/g. Results obtained by this method were compared with those obtained by the official thin-layer chromatography/densitometric method.

scholarly journals A Stability Indicating UPLC Method for the Determination of Tramadol Hydrochloride: Application to Pharmaceutical Analysis

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Kanakapura B. Vinay ◽  
Hosakere D. Revanasiddappa ◽  
Cijo M. Xavier ◽  
Pavagada J. Ramesh ◽  
Madihalli S. Raghu
Keyword(s):  
Limit Of Detection ◽  
Potassium Dihydrogen Phosphate ◽  
Reversed Phase ◽  
Forced Degradation ◽  
Dihydrogen Phosphate ◽  
Uv Detector ◽  
Limit Of Quantification ◽  
Tramadol Hydrochloride ◽  
Stability Indicating

The use of Ultra Performance Liquid Chromatography (UPLC), with a rapid 5-minute reversed phase isocratic separation on a 1.7 μm reversed-phase packing material to provide rapid ‘‘high throughput’’ support for tramadol hydrochloride (TMH) is demonstrated. A simple, precise and accurate stability-indicating isocratic UPLC method was developed for the determination of TMH in bulk drug and in its tablets. The method was developed using Waters Aquity BEH C18 column (100 mm × 2.1 mm, 1.7 μm) with mobile phase consisting of a mixture of potassium dihydrogen phosphate buffer of pH 2.8 and an equal volume of acetonitrile (60 : 40 v/v). The eluted compound was detected at 226 nm with a UV detector. The standard curve of mean peak area versus concentration showed an excellent linearity over a concentration range 0.5–300 μg mL−1 TMH with regression coefficient (r) value of 0.9999. The limit of detection (S/N =3) was 0.08 μg mL−1 and the limit of quantification (S/N =10) was 0.2 μg mL−1. Forced degradation of the bulk sample was conducted an accordance with the ICH guidelines. Acidic, basic, hydrolytic, oxidative, thermal and photolytic degradation were used to assess the stability indicating power of the method. TMH was found to degrade significantly in acidic, basic and oxidative stress conditions and stable in thermal, hydrolytic and photolytic conditions.

Liquid Chromatographic Determination of Residual Isocyanate Monomers in Plastics Intended for Food Contact Use

1995 ◽  
Vol 78 (3) ◽  
pp. 711-718 ◽  
Author(s):  
Andrew P Damant ◽  
Sue M Jickells ◽  
Laurence Castle
Keyword(s):  
Limit Of Detection ◽  
Internal Standard ◽  
Standard Addition ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Good Precision ◽  
Food Packages ◽  
Food Package ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method was developed for the analysis of 10 isocyanates in polyurethane articles and laminates intended for food use. Residual isocyanates are extracted by dichloromethane with concurrent derivatization by 9-(methylaminomethyl)anthracene. The resultant derivatives are analyzed by reversed-phase LC with fluorescence detection. Separation of the isocyanates was studied and optimized. Quantitation uses 1-naphthyl isocyanate as internal standard and standard addition to the food package. Validation demonstrated the method to have good precision (± 2–5%) and recovery (83–95%) for samples spiked with isocyanates at 0.1 mg/kg. The limit of detection was 0.03 mg/kg. Analysis of 19 commercial polyurethane or laminate food packages demonstrated that the method was not prone to interferences. Residues of diphenylmethane-4,4′-diisocyanate were detected in 5 packages and ranged from 0.14 to 1.08 mg/kg.

Liquid Chromatographic Determination of Sulfadiazine in Salmon by Postcolumn Derivatization and Fluorescence Detection

1995 ◽  
Vol 78 (5) ◽  
pp. 1161-1164 ◽  
Author(s):  
Theresa A Gehring ◽  
Larry G Rushing ◽  
Harold C Thompson
Keyword(s):  
Methylene Chloride ◽  
Coho Salmon ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Solid Phase Extraction Cartridge ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A reversed-phase (ODS-2) liquid chromatographic method was developed to determine low nanogramper-gram levels of sulfadiazine (SDZ) in salmon muscle tissue. SDZ was extracted with acetonitrile-aqueous 2% acetic acid (pH 3.0), partitioned into methylene chloride, and cleaned up by using a strong-cation-exchange, solid-phase extraction cartridge. SDZ was derivatized postcolumn with fluo-rescamine and detected by fluorescence. The limit of detection was 0.2 ng SDZ/g tissue. Recoveries from coho salmon tissue fortified with 1,5,10, and 20 ng SDZ/g tissue averaged 84.5,85.0,83.6, and 83.9%, respectively; recoveries from Atlantic salmon tissue fortified with 10 ng SDZ/g tissue averaged 82.6%.

Liquid-chromatographic determination of zomepirac in serum and plasma.

1982 ◽  
Vol 28 (3) ◽  
pp. 481-484 ◽  
Author(s):  
C L Welch ◽  
T M Annesley ◽  
H S Luthra ◽  
T P Moyer
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Liquid Chromatograph ◽  
Days Of Therapy

Abstract We describe a determination of zomepirac concentration in plasma and serum by reversed-phase "high-performance" liquid chromatography. The assay requires 1.0 mL of sample and involves diethyl ether extraction of zomepirac from an acidified sample, followed by concentration and injection into a liquid chromatograph. The column effluent is monitored at 330 nm. Retention times of zomepirac and the internal standard (tolmetin) are 3.8 and 2.7 min, respectively. The lower limit of detection for zomepirac in serum or plasma is 0.05 mg/L. Within-day precision (CV) of analysis in plasma or serum with zomepirac added (0.1-10.0 mg/L) ranged from 1.4 to 6.7%; between-day CV varied from 1.4 to 7.5%. Analytical recovery of zomepirac (1.0 mg/L) from serum and plasma was 77.6 (SD 3.5)% and 80.4 (SD 5.2)%, respectively. Numerous commonly coadministered drugs did not interfere. The elimination half-life of the drug was 1.8 h, and the peak plasma concentration ranged from 1.1 to 2.4 mg/L. Peak and trough concentrations measured throughout five days of therapy imply no accumulation.

scholarly journals High-Performance Liquid Chromatographic Method for the Determination of Moniliformin in Corn

1998 ◽  
Vol 81 (5) ◽  
pp. 999-1004 ◽  
Author(s):  
Célestin Munimbazi ◽  
Lloyd B Bullerman
Keyword(s):  
High Performance ◽  
Chromatographic Method ◽  
Solid Phase ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Detector Response ◽  
Dihydrogen Phosphate ◽  
Sodium Dihydrogen Phosphate ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Abstract A high-performance liquid chromatographic method using UV absorption was developed for determining moniliformin in corn. The toxin was extracted with water containing 1 % tetrabutylammonium hydrogen sulfate (w/v). Paired moniliformin was partitioned into dichloromethane, which was evaporated to dryness at 50 C. The residue was dissolved in water and applied to a disposable stronganion exchange solid-phase extraction tube. Adsorbed moniliformin was eluted from the tube with 0.05M sodium dihydrogen phosphate monohydrate (pH 5). It was determined by ion-pair reversed-phase chromatography and UV measurement at 229 nm. The minimum detectable amount of pure moniliformin was 0.25 ng/injection (signal-to-noise ratio = 3:1). The detector response was linear from 0.25 to at least 20 ng. The limit of determination was 0.025 μg/g corn. Recoveries of moniliformin from corn spiked at 0.025,0.05,0.25, and 1.0 μg/g averaged 96.5,96.2, 97.2, and 97.8% respectively

Development and Validation of Stability-Indicating HPLC Method for Roflumilast and Related Substances

2013 ◽  
Vol 781-784 ◽  
pp. 68-71 ◽  
Author(s):  
Fang Tan
Keyword(s):  
Limit Of Detection ◽  
Degradation Products ◽  
Reversed Phase ◽  
Hplc Method ◽  
Forced Degradation ◽  
Dihydrogen Phosphate ◽  
Column Temperature ◽  
Stability Indicating ◽  
Related Substances ◽  
Limit Of Quantitation

A reversed phase HPLC method was developed and validated for analysis of roflumilast, its related substances and degradation products, using Ecosil C18 column (250×4.6 mm, 5 μm) with a flow rate of 1.0 ml/min and detection wavelength of 215nm. The mobile phase was a mixture of acetonitrile and 0.005mol·L-1ammonium dihydrogen phosphate buffer pH 3.5 in the ratio of 48:52 (v/v). The samples were analyzed using 20 μl injection volume and the column temperature was maintained at 30°C. The limit of detection and limit of quantitation were found to be 2.6 ng/ml and 8ng/ml, respectively. The stability-indicating capability of method was established by forced degradation studies and method demonstrated successful separation of drug, its related substances and degradation products. The method is sensitive, specific, accurate, precise and stability indicating for the quantitation of drug, its related substances and other degradation compounds.

Simultaneous liquid-chromatographic determination of 12 common sedatives and hypnotics in serum.

1978 ◽  
Vol 24 (4) ◽  
pp. 657-662 ◽  
Author(s):  
P M Kabra ◽  
H Y Koo ◽  
L J Marton
Keyword(s):  
Serum Proteins ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Acetonitrile Solution ◽  
Column Temperature ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract We present a method for simultaneously determining 12 hypnotics and sedatives (primidone, methyprylon, phenobarbital, butabarbital, butalbital, ethchlorvynol, pentobarbital, amobarbital, phenytoin, glutethimide, secobarbital and methaqualone) in 200 microliter of serum. Serum proteins are precipitated with an acetonitrile solution containing 5-(4-methylphenyl)-5-phenylhydantoin, the internal standard. The drugs are eluted from a reversed-phase column with a mobile phase consisting of an acetonitrile/phosphate buffer, at a flow rate of 3.0 ml/min. The eluted drugs are detected by their absorption at 195 nm; their quantities are estimated from their peak heights. Each analysis requires no longer than 30 min at the optimum column temperature of 50 degrees C. The lower limit of detection for all of these drugs is less than 10 ng/sample for drug standard. A sensitivity of 1.0 mg/liter of serum is attained routinely for each of the drugs. Analytical recoveries for the 12 drugs varied from 94 to 112%, with good day-to-day precision (CV between 3.8 and 10.4%). Of more than 35 drugs tested for possible interference, only ethotoin interferes with the analysis of phenobarbital.

scholarly journals Stability-indicating liquid chromatographic method for quantification of new anti-epileptic drug lacosamide in bulk and pharmaceutical formulation

2012 ◽  
Vol 18 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Usmangani Chhalotiya ◽  
Kashyap Bhatt ◽  
Dimal Shah ◽  
Sunil Baldania ◽  
Jigar Patel
Keyword(s):  
Limit Of Detection ◽  
Chromatographic Determination ◽  
Chemical Oxidation ◽  
Reversed Phase ◽  
Limit Of Quantification ◽  
Pharmaceutical Dosage Form ◽  
Stability Indicating ◽  
Dry Heat ◽  
Alkali Hydrolysis ◽  
Liquid Chromatographic

An isocratic stability indicating reversed-phase liquid chromatographic determination was developed for the quantitative determination of lacosamide in the pharmaceutical dosage form. A Hypersil C-18, 4.5?m column with mobile phase containing acetonitrile-water (20:80, v/v) was used. The flow rate was 1.0 mL min-1 and effluents were monitored at 258 nm. The retention time of lacosamide was 8.9 min. The method was found to be linear in the concentration range of 5-100 ?g/ml and the recovery was found to be in the range of 99.15 - 100.09 %. The limit of detection and limit of quantification were found to be 2 ?g/ml and 5 ?g/ml, respectively. Lacosamide stock solutions were subjected to acid and alkali hydrolysis, chemical oxidation and dry heat degradation. The drug was found to be stable to the dry heat and acidic condition attempted. The proposed method was validated and successfully applied to the estimation of lacosamide in tablet dosage forms.

scholarly journals Effect of Temperature and Solvent Composition on Extraction of Fumonisins B1 and B2 from Corn Products

2000 ◽  
Vol 83 (3) ◽  
pp. 604-611 ◽  
Author(s):  
James F Lawrence ◽  
Barbara Niedzwiadek ◽  
Peter M Scott
Keyword(s):  
Residue Analysis ◽  
Reversed Phase ◽  
Solvent Composition ◽  
Effect Of Temperature ◽  
Technical Problems ◽  
Extraction Solvent ◽  
Corn Products ◽  
Phase Liquid ◽  
Corn Flakes ◽  
Fumonisins B1 And B2

Abstract Fumonisins B1 and B2 were extracted from naturally contaminated corn products by using different extraction solvent compositions (methanol–water, acetonitrile–methanol–water, ethanol–water, and 100% water) and a range of temperatures from ambient to 150°C. Ground samples of several corn products and 1 rice sample were mixed with an adsorbent material (Hydromatrix™), and the fumonisins were extracted in 2 sequential 5 min static extractions at various temperatures. The combined extracts were cleaned up and analyzed by reversed-phase liquid chromatography with fluorescence detection after o-phthaldialdehyde–mercaptoethanol derivatization. The results showed a clear influence of temperature and solvent composition on recovery of fumonisins from some matrixes. With acetonitrile–methanol–water (1 + 1 + 2) the quantity of fumonisins extracted from naturally contaminated taco shells almost tripled in going from 23° to 80°C, and increased by another 30% when ethanol–water (3 + 7) was used as extraction solvent at 80°C. Similar results were obtained with nacho chips. These effects were less pronounced with cornmeal, and small differences due to temperature and solvent composition were observed for corn flakes and rice. The ethanol–water extraction solvent combinations were specifically evaluated in an effort to use the cheapest, least toxic, and most environmentally friendly solvents for organic residue analysis. At 80°C, ethanol–water combinations performed equally or better than methanol–water (8 + 2) or acetonitrile–methanol–water (1 + 1 + 2), combinations which are commonly used for fumonisin extractions. Even 100% water was successful for extracting fumonisins from the products, except for rice. However, increased amounts of water created technical problems and required an increased amount of Hydromatrix in the samples prior to extraction.

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