scholarly journals Determination of Phenylbutazone Residues in Bovine Milk by Liquid Chromatography with UV Detection

1996 ◽  
Vol 79 (5) ◽  
pp. 1050-1053 ◽  
Author(s):  
E J Ian De Veau
Keyword(s):  
Milk Fat ◽  
Bovine Milk ◽  
Reversed Phase ◽  
Test Tube ◽  
Organic Layer ◽  
Uv Detector ◽  
Relative Standard ◽  
Vortex Mixer ◽  
Liquid Chromatographic

Abstract A published liquid chromatographic (LC) method was modified for quantitation of phenylbutazone (PBZ) residues in the range of 25-300 ng/mL in bovine milk. Milk samples (1 m└) were diluted with absolute ethanol and 25% NH4OH. Diethyl ether and petroleum ether were added sequentially to the milk extract and the mixture was agitated on a Vortex mixer to partition out milk fat. The organic phase was removed and discarded. Tetrahydrofuran- hexane (1 + 4) was added to the aqueous phase and the extract was acidified with 3M HCI. The samples were mixed on a Vortex mixer for 30 min, and centrifuged. The organic layer, containing PBZ, was transferred to a clean test tube. The organic solvents were evaporated to dryness under a stream of N2 at room temperature. The resulting extract was dissolved in 1 m└ mobile phase and filtered before injection. The chromatographic system was a C18 reversed-phase column connected to a UV detector set at 264 nm. Recoveries of PBZ from raw bovine milk fortified at 25- 300 ng/mL ranged from 79 to 84%; relative standard deviations (RSDs) ranged from 6 to 7%. The RSDs for incurred PBZ quantitated from 34 to 229 ng/mL ranged from 1 to 4%.

scholarly journals Simultaneous Determination of Residues of Chloramphenicol, Thiamphenicol, Florfenicol, and Florfenicol Amine in Farmed Aquatic Species by Liquid Chromatography/Mass Spectrometry

2003 ◽  
Vol 86 (3) ◽  
pp. 510-514 ◽  
Author(s):  
Jeffery M van de Riet ◽  
Ross A Potter ◽  
Melissa Christie-Fougere ◽  
B Garth Burns
Keyword(s):  
Reversed Phase ◽  
Organic Layer ◽  
Aquatic Species ◽  
Liquid Chromatography Mass Spectrometry ◽  
Relative Standard ◽  
Aqueous Layer ◽  
Operational Errors ◽  
Liquid Chromatographic ◽  
Reversed Phase Lc

Abstract A liquid chromatographic (LC)/mass spectrometric (MS) method was developed for determining the residues of chloramphenicol, thiamphenicol, florfenicol, and florfenicol amine in a number of aquatic species. The phenicols are extracted with acetone, the extracts are partitioned with dichloromethane, the aqueous layer is removed, and the organic layer is evaporated to dryness. The residue is dissolved in dilute acid and defatted with hexane, and the aqueous layer is prepared for analysis by LC. The phenicols are determined by reversed-phase LC by using a Hypersil C18-BD column with a water–acetonitrile gradient and MS detection using selectedion recording. Calibration curves were linear for all analytes between 0.015 and 0.425 ng injected. The relative standard deviations for measurements by the proposed method were <10% for all of the analytes studied, with re-coveries ranging from 71% for florfenicol amine to 107% for florfenicol in salmon tissue spiked at the 2 ng/g level. Detection limits of 0.1 ng/g for florfenicol and chloramphenicol, 0.3 ng/g for thiamphenicol, and 1.0 ng/g for florfenicol amine are easily obtainable. The operational errors, interferences, and recoveries for spiked samples compare favorably with those obtained by established LC methodology. The proposed method is simple, rapid, and specific for monitoring residues of chloramphenicol, thiamphenicol, florfenicol, and florfenicol amine in a number of aquatic species.

scholarly journals Determination of Omeprazole in Bulk and Injectable Preparations by Liquid Chromatography

2003 ◽  
Vol 86 (3) ◽  
pp. 501-504 ◽  
Author(s):  
Alexandre Schubert ◽  
Almeci L Werle ◽  
Cleber A Schmidt ◽  
Cristiane Codevilla ◽  
Lisiane Bajerski ◽  
...  
Keyword(s):  
Room Temperature ◽  
Reversed Phase ◽  
Constant Flow ◽  
Uv Detector ◽  
Constant Flow Rate ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Liquid Chromatographic ◽  
Interday Precision

Abstract An accurate, simple, reproducible, and sensitive liquid chromatographic method was developed and validated for the determination of omeprazole in powder for injection and in pellets. The analyses were performed at room temperature on a reversed-phase C18 column of 250 × 4.6 mm id, 5 μm particle size. The mobile phase, composed of methanol–water (90 + 10, v/v), was pumped at a constant flow rate of 1.5 mL/min. Detection was performed on a UV detector at 301 nm. The method was validated in terms of linearity, precision, accuracy, and ruggedness. The response was linear in the range 32–48 μg/mL (r2 = 0.9976). The relative standard deviation values for intra-and interday precision studies were 1.22 and 1.56% for injectable and 2.13 and 2.45% for pellets, respectively. Recoveries ranged between 95.81 and 100.48%.

scholarly journals Determination of Dyclonine Hydrochloride by a HPLC Method and Camphor and Menthol by a GC Method in Compound Lotion

2013 ◽  
Vol 2013 ◽  
pp. 1-4
Author(s):  
Suying Ma ◽  
Haixia Lv ◽  
Xiaojun Shang
Keyword(s):  
Retention Time ◽  
High Performance ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Hplc Method ◽  
Ionization Detector ◽  
Uv Detector ◽  
Flame Ionization ◽  
Liquid Chromatographic

A high performance liquid chromatographic (HPLC) method with UV detector for the determination of dyclonine hydrochloride and a gas chromatography (GC) method with flame ionization detector (FID) for the determination of camphor and menthol in lotion were developed. The developed HPLC method involved using a SinoChoom ODS-BP C18reversed-phase column (5 μm, 4.6 mm × 200 mm) and mobile phase consisting of acetonitrile : water : triethylamine in a ratio of 45 : 55 : 1.0; pH was adjusted to 3.5 with glacial acetic acid. The developed GC method for determination of camphor and menthol involved using an Agilent 19091J-413 capillary chromatographic column (30 m × 320 μm × 0.25 μm). The two methods were validated according to official compendia guidelines. The calibration of dyclonine hydrochloride for HPLC method was linear over the range of 20–200 μg/mL. The retention time was found at 6.0 min for dyclonine hydrochloride. The calibration of camphor and menthol of GC method was linear over the range of 10–2000 μg/mL. The retention time was found at 2.9 min for camphor and 3.05 min for menthol. The proposed HPLC and GC methods were proved to be suitable for the determination of dyclonine hydrochloride, camphor, and menthol in lotion.

scholarly journals Application of Liquid Chromatography to the Simultaneous Determination of Acetylsalicylic Acid, Caffeine, Codeine, Paracetamol, Pyridoxine, and Thiamine in Pharmaceutical Preparations

2001 ◽  
Vol 84 (3) ◽  
pp. 676-683 ◽  
Author(s):  
Natividad Ramos-Martos ◽  
Francisco Aguirre-Gómez ◽  
Antonio Molina-Díaz ◽  
Luis F Capitán-Vallvey
Keyword(s):  
Salicylic Acid ◽  
Acetylsalicylic Acid ◽  
Simultaneous Determination ◽  
Pharmaceutical Preparations ◽  
Reversed Phase ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract This paper describes a rapid reversed-phase liquid chromatographic method, with UV detection, for the simultaneous determination of acetylsalicylic acid, caffeine, codeine, paracetamol, pyridoxine, and thiamine in pharmaceutical preparations. A reversed-phase C18 Nucleosil column is used. The mobile phase consists of 2 successive eluants: water (5 min) and acetonitrile–water (75 + 25, v/v; 9 min), both adjusted to pH 2.1 with phosphoric acid. Before determination acetylsalicylic acid is completely converted to salicylic acid by alkaline hydrolysis. Salicylic acid, caffeine, paracetamol, pyridoxine, and thiamine are all detected at 285 nm, whereas codeine is detected at 240 nm. Calibration curves were linear for salicylic acid, caffeine, paracetamol, and pyridoxine in the range of 50–500 mg/L, and for codeine and thiamine in the range of 50–1000 mg/L. The method was applied to the analysis of 13 fortified commercial pharmaceutical preparations. Recoveries ranged from 92.6 to 105.5%, with relative standard deviations of 1.1–5.8%.

scholarly journals Rapid Determination of Ampicillin in Bovine Milk by Liquid Chromatography with Fluorescence Detection

1997 ◽  
Vol 80 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Catharina Y W Ang ◽  
Luo Wenhong
Keyword(s):  
Fluorescence Detection ◽  
Rapid Determination ◽  
Bovine Milk ◽  
Skim Milk ◽  
Reversed Phase ◽  
Coefficients Of Variation ◽  
Whole Milk ◽  
Liquid Chromatographic ◽  
Clear Supernatant

Abstract A rapid and sensitive liquid chromatographic (LC) method was developed for the determination of am- picillin residues in raw bovine milk, processed skim milk, and pasteurized, homogenized whole milk with vitamin D. Milk samples were deprote- inized with trichloroacetic acid (TCA) and acetonitrile. After centrifugation, the clear supernatant was reacted with formaldehyde and TCA under heat. The major fluorescent derivative of ampicillin was then determined by reversed-phase LC with fluorescence detection. Average recoveries of ampicillin fortified at 5,10, and 20 ppb (ng/mL) were all >85% with coefficients of variation <10%. Limits of detection ranged from 0.31 to 0.51 ppb and limits of quantitation, from 0.66 to 1.2 ppb. After appropriate validation, this method should be suitable for rapid analysis of milk for ampicillin residues at the tolerance level of 10 ppb.

scholarly journals Development of a New High-Performance Liquid Chromatographic Method for the Determination of Ceftazidime

2008 ◽  
Vol 91 (4) ◽  
pp. 739-743 ◽  
Author(s):  
Andréia de Haro Moreno ◽  
Hérida Regina Nunes Salgado
Keyword(s):  
High Performance ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Hplc Method ◽  
Calibration Graph ◽  
Raw Material ◽  
Relative Standard ◽  
Validation Parameters ◽  
Liquid Chromatographic

Abstract A rapid, accurate, and sensitive high-performance liquid chromatographic (HPLC) method was developed and validated for the determination of ceftazidime in pharmaceuticals. The method validation parameters yielded good results and included range, linearity, precision, accuracy, specificity, and recovery. The excipients in the commercial powder for injection did not interfere with the assay. Reversed-phase chromatography was used for the HPLC separation on a Waters C18 (WAT 054275; Milford, MA) column with methanolwater (70 + 30, v/v) as the mobile phase pumped isocratically at a flow rate of 1.0 mL/min. The effluent was monitored at 245 nm. The calibration graph for ceftazidime was linear from 50.0 to 300.0 g/mL. The values for interday and intraday precision (relative standard deviation) were <1. The results obtained by the HPLC method were calculated statistically by analysis of variance. We concluded that the HPLC method is satisfactory for the determination of ceftazidime in the raw material and pharmaceuticals.

Liquid Chromatographic Determination of Diclazuril in Premix and Supplemented Feed: Interlaboratory Study

1994 ◽  
Vol 77 (6) ◽  
pp. 1359-1361 ◽  
Author(s):  
Andre Fontaine ◽  
Karel Haustraete
Keyword(s):  
Solid Phase ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Reversed Phase ◽  
Poultry Feed ◽  
Uv Detector ◽  
Relative Standard ◽  
Liquid Chromatographic

Abstract Diclazuril, Janssen Research Compound R 64433 (Clinacox), is analyzed by liquid chromatography (LC). Compound R 062646, with a structure analogous to that of diclazuril, is used as internal standard. The drug is extracted from feed with acidified methanol. Diclazuril is then isolated by solid-phase extraction (SPE) with a cartridge containing a C18 phase. The eluate is evaporated, and the residue is redissolved in dimethylformamide. An aliquot is injected onto a reversed-phase ODS LC column, and the drug quantitated at 280 nm with a UV detector. Peak areas are obtained at the retention times corresponding to the internal standard and diclazuril. The quantity of active ingredient is determined by comparing the ratio of the peak height of diclazuril to that of internal standard in the sample with the same ratio in a single calibration solution. SPE is not necessary for the analysis of premixes. Eleven laboratories participated in the collaborative study. Laboratories were provided with 2 samples of premixes and 3 samples of feed for poultry. Feed sample K1 was sent to only 6 laboratories. The reproducibility relative standard deviations (RSDRS) were 7.38 and 7.53% for the 2 premixes and 9.67,13.65, and 18.61% for the 3 samples of supplemented feed.

scholarly journals Identification of Allantoin, Uric Acid, and Indoxyl Sulfate as Biochemical Indicators of Filth in Food Packaging by LC

2001 ◽  
Vol 84 (3) ◽  
pp. 782-788 ◽  
Author(s):  
Marvin Carlson ◽  
Richard D Thompson
Keyword(s):  
Uric Acid ◽  
Food Packaging ◽  
Reversed Phase ◽  
Indoxyl Sulfate ◽  
Rat Urine ◽  
Relative Standard ◽  
Analyte Content ◽  
Corrugated Cardboard ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method was developed for the determination of allantoin, uric acid, and indoxyl sulfate in mammalian urine contaminated packaging material including paper bagging, corrugated cardboard, grayboard, and burlap bagging. The procedure involves solvent extraction and isolation of the 3 analytes by reversed-phase LC with ultraviolet detection at 225 nm for allantoin and 286 nm for uric acid and indoxyl sulfate. The composition of authentic mammalian urine such as mouse, rat, cat, dog, and human were also determined with regard to the 3 compounds of interest. A linear concentration range of 0.11–20.4, 0.02–10.0, and 0.04–30.0 μg/mL was obtained for allantoin, uric acid, and indoxyl sulfate, respectively. Limits of detection (LOD) and quantitation (LOQ) were 0.0104 and 0.0345 μg/mL for allantoin; 0.0018 and 0.0060 μg/mL for uric acid; and 0.0049 and 0.0165 μg/mL for indoxyl sulfate, respectively. Interday relative standard deviation values for a mixture of standard allantoin, uric acid, and indoxyl sulfate (n = 5) were 0.97, 0.80, and 0.94%, respectively. Analyte composition for 5 types of authentic mammalian urine varied from 0.19–6.88 mg/mL allantoin; 0.08–0.57 mg/mL uric acid; and 0.03–0.78 mg/mL indoxyl sulfate. Analyte content for 8 samples including 2 samples each for paper, cardboard, grayboard, and burlap bagging each contaminated with mouse or rat urine ranged from <LOD to 4598 μg/gm allantoin; <LOD to 202 μg/gm uric acid; and 17.5 to 616 μg/gm indoxyl sulfate. Recoveries of allantoin, uric acid, and indoxyl sulfate from 11 fortified samples (4 types) for both mouse and rat urine ranged from 28.2 to 114.1% for allantoin; 32.6 to 123.4% for uric acid; and 52.6 to 118.2% for indoxyl sulfate.

scholarly journals Determination of D-Malic Acid in Apple Juice by Liquid Chromatography: Collaborative Study

1996 ◽  
Vol 79 (1) ◽  
pp. 50-54 ◽  
Author(s):  
Thomas A Eisele ◽  
K Adadevoh ◽  
G Anderson ◽  
A Brause ◽  
D Briesmeister ◽  
...  
Keyword(s):  
Malic Acid ◽  
Apple Juice ◽  
Copper Acetate ◽  
Collaborative Study ◽  
Reversed Phase ◽  
Uv Detector ◽  
Paired Samples ◽  
Study Results ◽  
Liquid Chromatographic

Abstract Eleven laboratories collaboratively studied a liquid chromatographic (LC) method for determination of D-malic acid in apple juice. The mobile phase consisted of 16 mM L-valine and 8 mM copper acetate adjusted to pH 5.5 with NaOH. The UV detector was set at 330 nm, and a single reversed-phase LC column was used. Seven paired samples containing various amounts of D-malic acid ranging from 0 to 188 mg/100 mL of 12 Brix pasteurized apple juice were tested by each collaborator. Repeatability and reproducibility coefficients of variation ranged from 1.0 to 3.5% and 7.7 to 11.7%, respectively, within the range of 26 to 188 mg D-malic acid/100 mL of 12 Brix apple juice. The collabora tive study results demonstrated that the method could quantitate the economic adulteration of ap ple juice with DL-malic acid at lower levels than those reported with previous methods. The LC method for determination of D-malic acid in apple juice has been adopted first action by AOAC INTERNATIONAL.

scholarly journals Simultaneous Determination of Chlorpheniramine Maleate and Dexamethasone in a Tablet Dosage Form by Liquid Chromatography

2005 ◽  
Vol 88 (6) ◽  
pp. 1677-1683 ◽  
Author(s):  
María A Moyano ◽  
María A Rosasco ◽  
María T Pizzorno ◽  
Adriana I Segall
Keyword(s):  
Potassium Phosphate ◽  
Reversed Phase ◽  
Chlorpheniramine Maleate ◽  
Constant Flow Rate ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Tablet Dosage ◽  
Liquid Chromatographic ◽  
Interday Precision

Abstract An accurate, simple, reproducible, and sensible liquid chromatographic method was developed and validated for the determination of chlorpheniramine maleate and dexamethasone in a tablet formulation. The analysis was performed at room temperature on a reversed-phase C18 column with UV detection at 254 nm. The mobile phase consisted of 7.5 mM monobasic potassium phosphate in methanol–water (62.5 + 37.5) at a constant flow rate of 1 mL/min. The method was validated in terms of linearity, precision, accuracy, and specificity by forced decomposition of chlorpheniramine maleate and dexamethasone initiated by using acid, base, water, hydrogen peroxide, heat, and light. The response was linear in the ranges of 0.04–0.12 and 0.006–0.016 mg/mL for chlorpheniramine maleate (r2 = 0.9999) and dexamethasone (r2 = 0.9994), respectively. The relative standard deviation values for intra- and interday precision studies were 2.39 and 2.02, respectively, for chlorpheniramine maleate and 2.39 and 1.25, respectively, for dexamethasone. Recoveries ranged from 95.07 to 101.95% for chlorpheniramine maleate and from 97.75 to 102.10% for dexamethasone.

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