Determination of Monensin in Edible Bovine Tissues and Milk by Liquid Chromatography

1995 ◽  
Vol 78 (3) ◽  
pp. 668-673 ◽  
Author(s):  
John W Moran ◽  
James M Turner ◽  
Mark R Coleman
Keyword(s):  
Liquid Chromatography ◽  
Silica Gel ◽  
Analysis Time ◽  
Bovine Muscle ◽  
Limit Of Quantitation ◽  
Wavelength Detector ◽  
Acidic Conditions ◽  
Postcolumn Derivatization

Abstract A method is described for detection and quantitation of monensin in bovine tissues by liquid chromatography (LC) with postcolumn derivatization (PCD) with vanillin. Monensin is extracted from the tissues by homogenization with methanol–water and is isolated and concentrated by liquid–liquid partition and sorbent extraction with silica gel. Monensin is mixed postcolumn with vanillin under acidic conditions and heated, and the resulting products are measured by a variable-wavelength detector at 520 nm. The method has a limit of quantitation of 5 ppb monensin in milk and 25 ppb monensin in bovine muscle, liver, kidney, and fat. Standard recovery over the levels and matrixes tested ranged from 80 to 88%. The method is an improvement in specificity, accuracy, and analysis time over existing monensin residue methods for bovine tissues.

Determination of Monensin in Chicken Tissues by Liquid Chromatography with Postcolumn Derivatization

1994 ◽  
Vol 77 (4) ◽  
pp. 885-890 ◽  
Author(s):  
John W Moran ◽  
J Matthew Rodewald ◽  
Alvin L Donoho ◽  
Mark R Coleman
Keyword(s):  
Liquid Chromatography ◽  
Silica Gel ◽  
Chicken Tissues ◽  
Chicken Muscle ◽  
Limit Of Quantitation ◽  
Microbiological Techniques ◽  
Wavelength Detector ◽  
Acidic Conditions ◽  
Postcolumn Derivatization

Abstract A method is described for the detection and quantitation of monensin in chicken tissues by liquid chromatography with postcolumn derivatization with vanillin. Monensin is extracted from the tissues by homogenization with methanol–water and is isolated and concentrated by liquid–liquid partition and sorbent extraction with silica gel. Monensin is mixed postcolumn with vanillin under acidic conditions and heated, and the resulting products are measured by a variable-wavelength detector operating at 520 nm. The method has a limit of quantitation of 0.025 μg/g and is validated for use in the analyses of chicken muscle, liver, and skin (with adhering fat tissues) for monensin. Standard recoveries from the 3 tissue types tested at 3 levels ranged from 82 to 96%. The method represents an improvement in specificity, accuracy, and analysis time over existing methods, which use microbiological techniques.

Determination of Narasin in Raw Material, Premix, and Animal Feeds by Liquid Chromatography and Correlation to Microbiological Assay

1994 ◽  
Vol 77 (4) ◽  
pp. 821-828 ◽  
Author(s):  
John M Rodewald ◽  
John W Moran ◽  
Alwin L Donoho ◽  
Mark R Coleman
Keyword(s):  
Liquid Chromatography ◽  
Chemical Composition ◽  
Microbiological Assay ◽  
Raw Material ◽  
Reference Standard ◽  
Wavelength Detector ◽  
Acidic Conditions ◽  
The Individual ◽  
Postcolumn Derivatization

Abstract A method is described for the detection and quantitation of narasin in raw material, premix, and feeds by liquid chromatography (LC) and postcolumn derivatization (PCD) with vanillin. Narasin was mixed with vanillin under acidic conditions and heated, and the resulting products were measured by a variable-wavelength detector operating at 520 nm. The LC responses of narasin and narasinlike factors were determined and correlated to the microbiological response of each factor as determined with Streptococcus faecium. Narasin reference standard was characterized in the same manner as the individual factors. The chemical composition of the reference standard (i.e., the amounts of narasin factors expressed in percent) combined with the relative microbiological potency value was used to calculate the biopotency contribution of each narasin factor. A formula was used to transform chemical composition values (amounts of narasin factors expressed in percent) of the reference standard to total microbiological activity as directly obtained from the microbiological assay. The LC method was validated by analyses of raw material, premix, and cattle and poultry rations.

scholarly journals Reverse phase-liquid chromatography assisted protocol for simultaneous determination of lamivudine and tenofovir disoproxil fumarate in combined medication used to control HIV infection: an investigative approach

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Vaibhav S. Adhao ◽  
Suraj R. Chaudhari ◽  
Jaya P. Ambhore ◽  
Sunil Sangolkar ◽  
Raju R. Thenge ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Hiv Infection ◽  
Simultaneous Determination ◽  
Tenofovir Disoproxil Fumarate ◽  
Solvent System ◽  
Array Detector ◽  
Technical Requirements ◽  
Relative Standard ◽  
Limit Of Quantitation

Abstract Background Human immunodeficiency virus (HIV) causes severe life-threatening condition, i.e., AIDS. HIV destabilises an individual’s ability to prevent infection. Therefore, the combine medication lamivudine (LVD) and tenofovir disoproxil fumarate (TDF) are prescribed to suppress the amount of HIV infection in individual’s body; thus, the individual’s immune system could function properly. Consequently, the objective of present research work was to investigate robust and sensitive liquid chromatography avenue for simultaneous determination of lamivudine and tenofovir disoproxil fumarate in pure material and combined dosage form. Results The reversed-phase chromatographic separation has been performed through Hypersil BDS C18 column using solvent system composed of 10 mM potassium dihydrogen phosphate (pH 4.0): acetonitrile (60:40% v/v). The determination was executed at 30 oC at 1 mL/min rate for flow of solvent system through column. The eluents of column were monitored at 265 nm using Photodiode Array detector has revealed admirable retention times, i.e., 4.67 and 8.78 min for both drugs, respectively. The calibration curve demonstrated excellent linearity in the range of 10–50 μg/mL for lamivudine and tenofovir disoproxil fumarate with better determination coefficients was more than (r2 0.999). Conclusion The estimable method was effectively validated with respect to accuracy, precision, sensitive (limit of detection and limit of quantitation), robustness, ruggedness, and for selectivity and specificity. The value less than 2 for percentage relative standard deviation for accuracy, precision, robustness, and ruggedness satisfying the acceptance criteria as per procedure of International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use.

High-Speed Liquid Chromatographic Determination of o-Phenylphenol Residues in Citrus Products

1976 ◽  
Vol 59 (1) ◽  
pp. 162-164
Author(s):  
Samuel K Reeder
Keyword(s):  
Liquid Chromatography ◽  
Quantitative Analysis ◽  
High Speed ◽  
Steam Distillation ◽  
Chromatographic Determination ◽  
Analysis Time ◽  
Hexane Extraction ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A method is presented for the quantitative analysis of o-phenylphenol residues in citrus oils, encapsulated flavors, and dried meal. The method utilizes high-speed liquid chromatography for the determination after specific sample preparations for each material. These preparations include hexane extraction of acidified basic extracts or steam distillation and extraction. The limit of the analysis is <1 ppm with an analysis time of <45 min.

Extraction, Cleanup, and Quantitative Determination of Aflatoxins in Corn

1980 ◽  
Vol 63 (3) ◽  
pp. 631-633 ◽  
Author(s):  
James E Thean ◽  
David R Lorenz ◽  
David M Wilson ◽  
Kathleen Rodgers ◽  
Richard C Gueldner
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Quantitative Determination ◽  
Ammonium Sulfate ◽  
Silica Gel ◽  
Normal Phase ◽  
Aqueous Methanol ◽  
Normal Phase Hplc ◽  
Water Saturated

Abstract A method is proposed for extraction and cleanup of corn samples for the quantitation of 4 aflatoxins by high pressure liquid chromatography (HPLC). After aqueous methanol extraction, ammonium sulfate treatment, and partition of aflatoxins into chloroform, sample extracts are partially purified on Sep-Pak cartridges or small columns packed with HPLC grade silica; cleanup requires only 13 mL solvent/sample. Aflatoxins B1, B2, G1, and G2 in the purified extract are resolved in ca 10 min by normal phase HPLC on a microparticulate (5 μm) silica gel column with a 50% water-saturated chloroform-cyclohexaneacetonitrile- ethanol solvent, and are measured by ultraviolet fluorescence in a silica gel-packed flowcell. Recoveries of added aflatoxins B1, B2, G1, and G2 were 84–118 % at levels of 1.5–125 μg/kg

scholarly journals Simultaneous Determination of Residual Antiparasitic Lactones in Bovine Muscle and Liver by Liquid Chromatography with Fluorescence Detection

2003 ◽  
Vol 86 (3) ◽  
pp. 490-493 ◽  
Author(s):  
Tomoko Nagata ◽  
Fumio Miyamoto ◽  
Yasuyuki Hasegawa ◽  
Eiichi Ashizawa
Keyword(s):  
Liquid Chromatography ◽  
Ethyl Acetate ◽  
Simultaneous Determination ◽  
Fluorescence Detection ◽  
Dimethyl Formamide ◽  
Bovine Muscle

Abstract Abamectin, doramectin, eprinomectin, ivermectin, milbemectin, and moxidectin in bovine muscle and liver were extracted with acetonitrile. The extracts were partitioned with n-hexane and then evaporated to dryness. The residue was cleaned up on Bond Elute NH2 cartridge, and the drugs were eluted from the cartridge with methanol–ethyl acetate (3 + 7). The eluate was evaporated to dryness, and residues were derivatized with N,N-dimethyl-formamide–acetic anhyride-1-methylimidazole. The derivatives were determined by liquid chromatography with fluorescence detection. Recoveries of the 6 drugs were 79.6–63.8% in muscle and 71.6–60.6% in liver at 0.01 ppm levels. The quantitation limits were 5 ppb for each drug.

scholarly journals Development and Validation of Chemometrics-Assisted Spectrophotometry and Liquid Chromatography Methods for the Simultaneous Determination of the Active Ingredients in Two Multicomponent Mixtures Containing Chlorpheniramine Maleate and Phenylpropanolamine Hydrochloride

2007 ◽  
Vol 90 (4) ◽  
pp. 957-970 ◽  
Author(s):  
Ghada M Hadad ◽  
Alaa El-Gindy ◽  
Waleed M M Mahmoud
Keyword(s):  
Liquid Chromatography ◽  
Simultaneous Determination ◽  
Analytical Sensitivity ◽  
Multicomponent Mixtures ◽  
Active Ingredients ◽  
Chlorpheniramine Maleate ◽  
Calibration Methods ◽  
Limit Of Quantitation ◽  
Phenylpropanolamine Hydrochloride

Abstract Multivariate spectrophotometric calibration and liquid chromatography (LC) methods were used for the simultaneous determination of the active ingredients in 2 multicomponent mixtures containing chlorpheniramine maleate and phenylpropanolamine hydrochloride with ibuprofen and caffeine (mixture 1) or with propyphenazone (mixture 2). For the multivariate spectrophotometric calibration methods, principal component regression (PCR) and partial least squares (PLS-1), a calibration set of the mixtures consisting of the components of each mixture was prepared in distilled water. A leave-1-out cross-validation procedure was used to find the optimum numbers of latent variables. Analytical parameters such as sensitivity, selectivity, analytical sensitivity, limit of quantitation, and limit of detection were determined for both PLS-1 and PCR. The LC method depends on the use of a cyanopropyl column with the mobile phase acetonitrile-12 mM ammonium acetate, pH 5.0 (25 + 75, v/v), for mixture 1 or acetonitrile10 mM potassium dihydrogen phosphate, pH 4.7 (45 + 55, v/v), for mixture 2; the UV detector was set at 212 nm. In spite of the presence of a high degree of spectral overlap of these components, they were rapidly and simultaneously determined with high accuracy and precision, with no interference from the matrix excipients. The proposed methods were successfully applied to the analysis of pharmaceutical formulations and laboratory-prepared mixtures containing the 2 multicomponent combinations.

scholarly journals Determination of 7B3 Residues in Cotton Plants by Liquid Chromatography/Mass Spectrometry

2009 ◽  
Vol 92 (1) ◽  
pp. 302-306 ◽  
Author(s):  
Xiao-Jing Yan ◽  
Xiao-Mei Liang ◽  
Yan-Jun Xu ◽  
Shu-Hui Jin ◽  
Dao-Quan Wang
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Limit Of Detection ◽  
Reversed Phase ◽  
Liquid Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Relative Standard ◽  
Limit Of Quantitation ◽  
Cotton Plants

Abstract A method was developed for the determination of 7B3 (12-propyloxyimino-1,15-pentadecanlactam), a novel macrolactam fungicide, by liquid chromatography/mass spectrometry (LC/MS) with positive electrospray ionization (ESI+). The method used a reversed-phase C18 column and acetonitrilewater (60 + 40, v/v) mobile phase. The quick, easy, cheap, effective, rugged, and safe method was used for extraction of 7B3 from cotton plants, which involved the extraction of 10 g homogenized sample with 10 mL acetonitrile, followed by the addition of 4 g anhydrous MgSO4 and 1.0 g NaCl. After centrifugation, 1 mL of the buffered acetonitrile extract was transferred into a tube containing 50 mg primary secondary amine sorbent and 100 mg anhydrous MgSO4. After shaking and centrifugation, the final extract was transferred to an autosampler vial for concurrent analysis by LC/MS. The results of 7B3 determined by LC/MS in the selective ion monitoring mode were linear, and the matrix effect of the method was evaluated. The average recoveries of 7B3 fortified at different levels were within 84.1100.2, and the relative standard deviations were <7.5 for all samples analyzed. The method limit of detection and the limit of quantitation values were 0.03 and 0.1 mg/kg, respectively. The proposed method was successfully applied to determine 7B3 residues in practical samples. This method is sensitive, accurate, reliable, simple, and safe.

scholarly journals Determination of Sulfonamides in Edible Salmon Tissue by Liquid Chromatography with Postcolumn Derivatization and Fluorescence Detection

1997 ◽  
Vol 80 (4) ◽  
pp. 751-755 ◽  
Author(s):  
Theresa A Gehring ◽  
Larry G Rushing ◽  
Harold C Thompson
Keyword(s):  
Acetic Acid ◽  
Liquid Chromatography ◽  
Fluorescence Detection ◽  
Coho Salmon ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Aqueous Acetic Acid ◽  
Postcolumn Derivatization

Abstract Fourteen sulfonamides—sulfanilamide, sulfadiazine, sulfathiazole, sulfapyridine, sulfam- erazine, sulfamethazine, sulfamethizole, sulfamethoxypyridazine, sulfachloropyridazine, sulfamonomethoxine, suļfadoxine, sulfamethoxazole, sulfadimethoxine, and sulfaquinoxoline—residues of which could be found in aquacultured species, were separated in <25 min by reversed-phase (C18) liquid chromatography (LC) with gradient elution. Analytes were extracted from edible salmon tissue (muscle and adhering skin) with acetonitrile—2% aqueous acetic acid, isolated with 2 liquid-liquid partitionings, and derivatized with fluorescamine after eluting from the column. The derivatives were detected by fluorescence. Recoveries (n = 4) from coho salmon fortified with sulfonamides at 5,10, and 20 ng/g tissue averaged 79.7± 7.3, 84.6 ± 7.7, and 88.2 ± 7.1%, respectively. Limits of quantitation were 5 ng/g tissue, for sulfanilamide, sulfamethoxypyridazine, and sulfaquinoxoline and 1 ng/g tissue for the remaining sulfonamides.

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