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.

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%.

Removal of contaminating substances before gas-liquid-chromatographic determination of aldosterone in urine.

1979 ◽  
Vol 25 (1) ◽  
pp. 141-143 ◽  
Author(s):  
V Graef ◽  
E Furuya ◽  
O Nishikaze
Keyword(s):  
Methylene Chloride ◽  
Periodic Acid ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
One Dimensional ◽  
Liquid Chromatographic Determination ◽  
Contaminating Substances ◽  
Liquid Chromatographic ◽  
Layer Chromatography

Abstract This paper deals with removal of contaminants before gas-chromatographic determination of aldosterone in urine. Urine is incubated with beta-glucuronidase, which hydrolyzes all beta-glucuronides except aldosterone-18-glucuronide. The contaminants (the aglycones released and other methylene chloride-soluble substances) are extracted with methylene chloride. Solvolysis of the aqueous phase liberates aldosterone from aldosterone-18-glucuronide, which then is extracted with methylene chloride and oxidized by use of periodic acid. The resulting lactone can be easily separated by one-dimensional thin-layer chromatography and determined by gas-liquid chromatography.

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

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.

Liquid Chromatographic Determination of Tetracycline Residues in Animal Feeds

1988 ◽  
Vol 71 (3) ◽  
pp. 477-480 ◽  
Author(s):  
Elizabeth E Martinez ◽  
Wilbert Shimoda
Keyword(s):  
Chromatographic Determination ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Double Extraction ◽  
Tetracycline Residues ◽  
Multiresidue Determination ◽  
Liquid Chromatographic ◽  
Layer Chromatography ◽  
Tetracycline Hcl

Abstract A liquid chromatographic method for the multiresidue determination of tetracyclines (TCs) in feeds is described. The levels of quantitation were 10 ppm each for tetracycline-HCl (TC), oxytetracycline (OTC), and chlortetracycline-HCl (CTC); the detection limit was 40 ppb for each. The calibration curves were linear between 2.5 and 100 ppm. The procedure involved double extraction with pH 2.0 and pH 4.5 Mcllvain buffers, cleanup on a Sephadex LH-20 column, separation on a Nova-Pak C18 column, and detection at 370 nm. Recoveries of 10 μg/g of each TC in multiresidue feed samples ranged from 55.8 to 75.5% for OTC, 71.6 to 100% for TC, and 22.4 to 60.6% for CTC. The identities of the TCs were confirmed by thin layer chromatography.

Liquid Chromatographic Determination of Moxidectin Residues in Cattle Tissues and Confirmation in Cattle Fat by Liquid Chromatography/Mass Spectrometry

1993 ◽  
Vol 76 (6) ◽  
pp. 1230-1235 ◽  
Author(s):  
Alisa Khunachak ◽  
Adrian R Dacunha ◽  
Steven J Stout
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Limit Of Detection ◽  
Parent Compound ◽  
Chromatographic Determination ◽  
Liquid Chromatography Mass Spectrometry ◽  
Liver And Kidney ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Moxidectin, a potent new endo- and ectoparasitic agent, is determined in cattle tissues by liquid chromatography (LC) with fluorescence detection. Moxidectin residues in cattle fat are confirmed with thermospray LC/mass spectrometry (MS). Moxidectin is extracted from the tissue with acetonitrile; the extract is partitioned with hexane, concentrated, and reacted with acetic anhydride, 1-methylimidazole, and dimethylformamide to produce a fluorescent product. The validated sensitivity of the LC/fluorescence method was 10 ppb, with a limit of detection typically between 1 and 2 ppb. Average recoveries from cattle fat, muscle, liver, and kidney were 99,95,89, and 92%, respectively. LC/MS confirmatory method determined the underivatized parent compound following the acetonitrilehexane partitioning step, with an average recovery of 108% at the 250 ppb level in cattle fat.

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.

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