Rapid Liquid Chromatographic Determination of Dimetridazole and Ipronidazole in Swine Feed

1987 ◽  
Vol 70 (4) ◽  
pp. 626-630 ◽  
Author(s):  
Jose E Roybal ◽  
Robert K Munns ◽  
Jeffrey A Hurlbut ◽  
Wilbert Shimoda ◽  
Thomas R Morrison ◽  
...  
Keyword(s):  
Chromatographic Analysis ◽  
Methylene Chloride ◽  
Drug Level ◽  
Chromatographic Determination ◽  
Acid Base ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Ppm Level

Abstract A simple and rapid method is described for the determination of dimetridazole (DMZ) and ipronidazole (IPR) in swine feeds at various levels (0.11-110 ppm). The drugs are released from feed by prewetting with a buffer, followed by extraction with either methanol or methylene chloride, depending on the drug level; if necessary, an acid-base cleanup is used before the liquid chromatographic analysis. The analytes are separated on a C18 column and monitored at 320 nm for detection and quantitation. Recoveries of DMZ from several feed formulations averaged 108% at the 92.8 ppm level with a standard deviation (SD) of 4.00% and a coefficient of variation (CV) of 3.70%, 101% at the 11.2 ppm level with an SD of 11.9% and a CV of 11.8%, and 100% at the 0.112 ppm level with an SD of 9.27% and a CV of 9.25%. Recoveries of IPR averaged 77.1% at the 12.9 ppm level with an SD of 1.75% and a CV of 2.27%; IPR recoveries averaged 35.2% at the 0.129 ppm level with an SD of 3.39% and a CV of 9.63%.

Gas-Liquid Chromatographic Determination of Fenvalerate Insecticide Residues in Processed Apple Products and By-Products

1982 ◽  
Vol 65 (5) ◽  
pp. 1106-1111
Author(s):  
Terry D Spittler ◽  
Robert J Argauer ◽  
Donald J Lisk ◽  
Ralph O Mumma ◽  
George Winnett ◽  
...  
Keyword(s):  
Chromatographic Analysis ◽  
Chromatographic Determination ◽  
Synthetic Pyrethroid ◽  
Insecticide Residues ◽  
Apple Products ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
By Products

Abstract Apples from trees treated in the field at 2-week intervals (9 foliar applications) with the synthetic pyrethroid insecticide fenvalerate (cyano(3-phenoxyphenyL)methyl 4-chloro-alpha-(1-methylethyl)- benzeneacetate) were processed into apple sauce, juice, pomace, and peels plus cores. Gas-liquid chromatographic analysis of the commodities for fenvalerate showed the sauce and juice to be essentially residue-free, the whole apples to contain about 0.4 ppm, and the pomace and peels plus cores to contain about 2 and 1.5 ppm, respectively. Agreement among 5 laboratories using modifications of the same basic method was good.

scholarly journals Liquid Chromatographic Determination of Tylosin in Mastitic Cow's Milk Following Therapy

1999 ◽  
Vol 82 (6) ◽  
pp. 1303-1307 ◽  
Author(s):  
Eva Dudriková ◽  
Sokol Jozef ◽  
Nagy Jozef
Keyword(s):  
Chromatographic Analysis ◽  
Chromatographic Determination ◽  
Maximum Residue Limit ◽  
Withdrawal Time ◽  
Milk Samples ◽  
Final Treatment ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Liquid chromatographic analysis of milk samples from 6 cows treated with tylosin in a veterinary practice indicated that tylosin persisted in milk for more than 3 days after the final treatment. The concentration of tylosin was not below the stated maximum residue limit (0.05 mg/kg). The milk from 3 cows being treated for mastitis catarrhalis chronica contained tylosin residues for 3.5 days after the last withdrawal time (72 h). No residue was detected in the milk of any animal 6 days after cessation of therapy.

Gas-Liquid Chromatographic Determination of Alachlor (2-Chloro-2′,6′-diethyh-N-(methoxymethyl)-acetanilide) Herbicide Residues in Corn and Soybeans

1976 ◽  
Vol 59 (4) ◽  
pp. 859-861
Author(s):  
Barbara Dohman Ammann ◽  
Daniel J Call ◽  
Hans A Draayer
Keyword(s):  
Methylene Chloride ◽  
Parent Compound ◽  
Chromatographic Determination ◽  
Field Application ◽  
Methylene Chloride Extract ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Layer Chromatography

Abstract A method has been developed for the extraction and determination of alachlor (2-chloro-2′,6′-diethyl-N-(methoxymethyl)-acetanilide) residues in green corn and soybeans. Residues are extracted with acetonitrile and cleaned up on a Fiorisil column. The methylene chloride extract is sufficiently clean for electron capture gas-liquid chromatographic analysis and for verification by thin layer chromatography. Average recoveries of spiked samples (0.2 ppm) were 69 and 82% for corn and soybeans, respectively. This procedure could be useful for the detection of the parent compound in these crops soon after field application, but it does not detect metabolites.

Gas-Liquid Chromatographic Determination of α-Cyano-3-phenoxybenzyl α-Isopropyl-4-chlorophenylacetate Residues in Cabbage

1977 ◽  
Vol 60 (4) ◽  
pp. 908-910
Author(s):  
Narayan S Talekar
Keyword(s):  
Chromatographic Determination ◽  
Electron Capture Detection ◽  
Liquid Chromatographic Method ◽  
Steel Column ◽  
Stainless Steel Column ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Ppm Level

Abstract A gas-liquid chromatographic method is described for residues of a synthetic pyrethroid, Sumicidin (α-cyano-3-phenoxybenzyl α-isopropyl-4-chlorophenylacetate), on cabbage. The plant material is Soxhlet-extracted with hexaneacetone (1+l) and subsequently cleaned up on Florisil with benzene-ethyl acetate (9+1) eluting solvent. Gas-liquid chromatographic analysis was performed on a 0.5 m × 2 mm stainless steel column containing 3% OV-101 + 3% Apiezon L on 80–100 mesh Gas-Chrom Q, with tritium electron capture detection. Sumicidin recovery was 97% when added at the 0.5 ppm level. Routine Sumicidin residue monitoring data presented.

Evaluation of Amperometric Detector for Liquid Chromatographic Determination of 2-Phenylphenol Residues in Orange Rind

1978 ◽  
Vol 61 (6) ◽  
pp. 1465-1468 ◽  
Author(s):  
Daniel E Ott
Keyword(s):  
Methylene Chloride ◽  
Amperometric Detection ◽  
Chromatographic Determination ◽  
Uv Detection ◽  
Liquid Chromatograph ◽  
Amperometric Detector ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A modular component liquid chromatograph has been assembled which has on-stream ultraviolet (UV) and amperometric detectors connected to a dual pen recorder. In this method, the commonly used UV detection technique provides a reference for direct comparisons of results from the amperometric detector. The system has been evaluated and applied to the determination of 2-phenylphenol (2PP) fortified in orange rind. The method is not tedious; before liquid chromatographic analysis, the sample is extracted with methylene chloride and cleaned up on a Florisil column. The method is sensitive to <1 ppm 2PP fortified in orange rind; there are no electrically oxidizable interferences, from control samples, in the chromatographic region of 2PP. Some background interference does appear from the same samples on the UV chromatogram. Thus, amperometric detection is more specific than UV detection for this application.

Liquid Chromatographic Determination of Zearalenone and a- and 0-Zearalenols in Milk

1988 ◽  
Vol 71 (6) ◽  
pp. 1176-1179 ◽  
Author(s):  
Peter M Scott ◽  
Guillaume A Lawrence
Keyword(s):  
Methylene Chloride ◽  
Solid Phase ◽  
Chromatographic Determination ◽  
Extraction Column ◽  
Hydrophilic Matrix ◽  
Unknown Factor ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract Previous research has demonstrated transmission of zearalenone and α- and β-zearalenols into the milk of cows and other animals. Since human intake of zearalenone and its metabolites via milk is an unknown factor in risk assessment of zearalenone and because appropriate methodology for their determination in milk is not available, a rapid and sensitive analytical method has been developed. Essentially, the method includes extraction with basic acetonitrile, acidification, partition into methylene chloride on a hydrophilic matrix, cleanup on an aminopropyl solid phase extraction column, and reverse- phase liquid chromatography with fluorescence detection. Recoveries from milk averaged 84% for zearalenone, 93% for α-zearalenol, and 90% for β-zearalenol at spiking levels of 0.5 to 20 ng/ mL. As little as 0.2 ng/mL of zearalenone and a-zearalenol and 2 ng/mL of 0-zearalenol can be detected in milk. These 3 compounds are stable in refrigerated milk for at least 2 weeks and in milk brought to boiling. Enzymes (β-glucuronidase and aryl sulfatase) may be added to milk prior to extraction to hydrolyze any conjugates

Semiautomated Liquid Chromatographic Determination of Clopidol in Poultry Feed

1971 ◽  
Vol 54 (3) ◽  
pp. 551-554 ◽  
Author(s):  
N E Skelly ◽  
R F Cornier
Keyword(s):  
Ion Exchange ◽  
Methanol Extract ◽  
Chromatographic Determination ◽  
Poultry Feed ◽  
Alumina Column ◽  
Accuracy And Precision ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Ppm Level

Abstract A semiautomated ion exchange-ultraviolet procedure has been developed for the determination of clopidol in poultry feed at the 40–250 ppm level. A methanol extract of the feed is injected into an alumina precolumn to remove interferences. The clopidol passes through the alumina column and is collected on an ion exchange column. With a specially designed elution apparatus the clopidol is removed by an acetic acid-methanol gradient. The eluate proceeds through a flowcell mounted in an ultraviolet spectrophotometer. Response of the spectrophotometer is monitored by a recorder. Concentration is determined by comparing the peak area in the resulting chromatogram with that of a standard. Accuracy and precision of this method are ±5% relative to the amount present (100±5 ppm).

Liquid Chromatographic Determination of Carbadox Residues in Animal Feed

1985 ◽  
Vol 68 (4) ◽  
pp. 653-657
Author(s):  
Jose E Roybal ◽  
Robert K Munns ◽  
Wilbert Shimoda
Keyword(s):  
Animal Feed ◽  
Chromatographic Determination ◽  
Alumina Column ◽  
Acid Base ◽  
Reverse Phase ◽  
Liquid Chromatographic Determination ◽  
Swine Feed ◽  
Liquid Chromatographic ◽  
Base Liquid

Abstract A liquid chromatographic (LC) method for determining residues of carbadox in the 0.01-10 ppm range in swine feed is described. Carbadox is extracted from ground feed with 25% acidified methanol- CHCl3, removed from emulsion-forming coextractables via an alumina column, separated from highly colored pigments by acid-base liquid- , liquid partitioning, and finally isolated from interferences on a second | alumina column. Isocratic reverse phase LC at 305 nm is used for quantitation. The average overall recovery at the 0.1,0.5, and 1.0 ppm J spike levels was 83.0% with a standard deviation of 2.04% and a coefficient of variation of 2.46 %.

Gas-Liquid Chromatographic Determination of Azinphos Ethyl in Human Plasma and in Mouse Plasma, Tissue, and Fat

1976 ◽  
Vol 59 (5) ◽  
pp. 1094-1096
Author(s):  
Vincent B Stein ◽  
Kenneth A Pittman
Keyword(s):  
Human Plasma ◽  
Limit Of Detection ◽  
Chromatographic Determination ◽  
Tissue Samples ◽  
Mouse Plasma ◽  
Glass Column ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A new method for the determination of azinphos ethyl (O,O-diethyl-S-(4-oxo-1,2,3-benzotriazin-3(4H)-ylmethyl) phosphorodithioate) in human plasma and in mouse plasma, tissue, and fat has been developed. The method is based on extraction with benzene or hexane and cleanup of fat and tissue samples by a minicolumn containing Florisil and sodium sulfate. Azinphos ethyl is eluted from the column with 10% acetonitrile in benzene and is concentrated to an appropriate volume for gas-liquid chromatographic analysis, using a 63Ni electron capture detector and a glass column containing 3% OV-1 on Gas-Chrom Q. The method is sensitive to 0.005 ppm in human plasma, 0.01 ppm in mouse plasma, 0.08 ppm in mouse liver, 0.05 ppm in mouse brain, and 0.10 ppm in mouse fat. The limit of detection is 2 pg; mean recoveries ranged from 96 to 98%.

Matrix Solid-Phase Dispersion Extraction and Liquid Chromatographic Determination of Ivermectin in Bovine Liver Tissue

1992 ◽  
Vol 75 (4) ◽  
pp. 655-658 ◽  
Author(s):  
Frank J Schenck ◽  
Steven A Barker ◽  
Austin R Long
Keyword(s):  
Methylene Chloride ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Bovine Liver ◽  
Chromatographic Determination ◽  
Liver Sample ◽  
Antiparasitic Drug ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A method for the isolation and liquid chromatographic (LC) determination of the antiparasitic drug ivermectin in bovine liver is presented. Liver samples (0.5 g) are blended with 2 g C18 (octadecylsilylderivatized silica packing material). A column made from the C18liver matrix is washed with 3 mL hexane, then the ivermectin is eluted with methylene chloride-ethyl acetate (3 + 1). After purification by alumina solid-phase extraction, the ivermectin is derivatized and analyzed by LC with fluorescence detection. The overall recovery of ivermectin added to liver was 74.6%. The lowest level validated in tissue by the method was 10 ppb, and the limit of detection was 1 ppb. This method and a classical extraction method gave comparable results for a liver sample that contained incurred ivermectin residues. The method uses small volumes of solvents, has a limited number of sample manipulations, and does not require solvent partitioning or backwashing of extracts. These characteristics make this method attractive when compared to classical isolation procedures for ivermectin.

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