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

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.

1974 ◽  
Vol 57 (6) ◽  
pp. 1383-1385
Author(s):  
David T Williams

Abstract A method has been developed for the determination of ethylenediaminetetraacetic acid in pickled vegetables after conversion to its tetramethyl ester. The ester is identified by gas-liquid chromatography and confirmed by gas-liquid chromatography-mass spectrometry. Recoveries from pickled beet samples spiked at 20-250 ppm were 87-74%.


1982 ◽  
Vol 65 (6) ◽  
pp. 1302-1304
Author(s):  
Yoshimi Kitada ◽  
Michiko Sasaki ◽  
Kaoru Tanigawa

Abstract A simple, rapid, efficient method has been developed for determining thiabendazole, o-phenylphenol, and diphenyl in citrus fruits by using high performance liquid chromatography, with fluorescence or ultraviolet detection. The compounds are extracted with ethyl acetate and separated from soluble fruit components on a LiChrosorb RP-8 column. Recovery of these compounds added to citrus fruits at 5 or 50 ppm levels was >93%; the limit of detection for the compounds is 1 ppm.


1981 ◽  
Vol 64 (1) ◽  
pp. 186-190
Author(s):  
Glenn E Martin ◽  
James M Burggraff ◽  
Randolph H Dyer ◽  
Peter C Buscemi

Abstract A procedure is described for the separation and determination of the following compounds which are found as congeners in alcoholic products: acetaldehyde, ethyl acetate, methanol, ethanol, n-propanol, isobutanol, n-butanol, acetic acid, and the amyl alcohols (2-methyl-l-butanol and 3-methyl-l-butanol). These compounds were separated by gas-liquid chromatography (GLC) using 5% Carbowax 20M on Carbopack B as the column packing. The results obtained by using this method were compared with those obtained using the present AOAC methods for these compounds. GLC chromatograms show better resolution by the method presented.


1980 ◽  
Vol 63 (6) ◽  
pp. 1224-1225
Author(s):  
David L Heikes

Abstract Methyl 4-chloroindolyl-3-acetate (MCIA), a naturally occurring auxin, has been identified in canned and frozen peas by gas-liquid chromatography (GLC)/mass spectrometry. Eight samples were analyzed for MCIA using slightly modified official AOAC multiple pesticide residue procedures employing GLC with microcoulometric detection. Levels of MCIA averaged 0.20 ppm for canned peas and 0.16 ppm for frozen peas. Recovery of MCIA from a fortified sample was 40%.


1976 ◽  
Vol 59 (1) ◽  
pp. 162-164
Author(s):  
Samuel K Reeder

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.


1980 ◽  
Vol 63 (1) ◽  
pp. 49-55
Author(s):  
Iwao Okuno ◽  
Dennis L Meeker

Abstract An analytical method is described for the determination of Compound 1080 (sodium fluoroacetate) residues in 1–10 g tissue. Sample extracts of tissues are cleaned up with silica gel, and Compound 1080 (as fluoroacetic acid) is separated by a micro-distillation procedure. The fluoroacetic acid in the distillate is derivatized with pentafluorobenzyl bromide to form pentafluorobenzyl fluoroacetate which is measured by electron capture gas-liquid chromatography. Recoveries of sodium fluoroacetate from fortified tissue samples averaged about 25%. Despite the limited recoveries, results were quite reproducible, and levels as low at 2 ppm were determined in fortified 1 g samples, and 0.2 ppm in 10 g samples. The method is relatively simple and has been used routinely in our laboratory for the analysis of various types of samples such as grain, and tissues from birds, rodents, and larger animals.


1979 ◽  
Vol 62 (1) ◽  
pp. 171-175 ◽  
Author(s):  
Alfred F Haeberer ◽  
Orestes T Chortyk

Abstract A method is presented for the determination of the plant growth regulator maleic hydrazide (MH; l,2-dihydro-3,6-pyridazinedione) in tobacco and tobacco smoke. Residues are converted to the bis(trimethylsilyl) derivative before analysis by gas-liquid chromatography. The method has been applied to cigarettes and condensed smoke and has been used to determine the per cent transfer of MH into cigarette smoke. Free MH residues could be determined directly on the tobacco samples, whereas total MH values were obtainable only after acid hydrolysis. In spite of large MH residues in tobacco, only 0.2% of the MH was transferred into smoke.


2003 ◽  
Vol 86 (4) ◽  
pp. 759-763 ◽  
Author(s):  
Peter Cavlovic ◽  
Mohan Mankotia ◽  
Peter Pantazopoulos ◽  
Peter M Scott

Abstract Nightshade berries containing glycoalkaloids can be a contaminant in green peas. Methodology was developed to detect this contamination. The glycoalkaloid α-solasonine was extracted from frozen green peas with 1% (v/v) acetic acid, cleaned up on a C18 cartridge, and determined by liquid chromatography with UV detection at 200 nm. Method performance characteristics for the determination of α-solasonine include linearity from 140 to 1500 ng injected (r = 0.9996–0.9999); recovery ranging from 68 to 79%; limit of quantitation (LOQ) = 4.5 ppm (280 ng standard), and limit of detection = 0.64 ppm (40 ng standard). At the LOQ, the expanded uncertainty at 95% confidence was 0.38 × the reported value. The method was applied to the detection of α-solasonine in frozen green peas in a 2-year study of 60 samples of frozen green peas from Ontario, Canada. None of the samples contained α-solasonine. No unripe berries of Solanum nigrum were detected visually in the samples.


1983 ◽  
Vol 66 (4) ◽  
pp. 909-912 ◽  
Author(s):  
Steven P Swanson ◽  
Venkatachalam Ramaswamy ◽  
Val R Beasley ◽  
William B Buck ◽  
Harold H Burmeister

Abstract The gas-liquid chromatographic method for the determination of T-2 toxin in plasma is described. The toxin is extracted with benzene, washed with aqueous sodium hydroxide, and chromatographed on a small Florisil column; the heptafluorobutyryl derivative is prepared by reaction with heptafluorobutyrylimidazole. The T-2 HFB derivative is chromatographed onOV-1 at 230°C and measured with an electron capture detector. Iso-T-2, an isomer of T-2 toxin, is added to samples as an internal standard before extraction. Recoveries averaged 98.0 ± 5.5% at levels ranging from 50 to 1000 ng/m L. The limit of detection is 25 ng/mL.


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