Liquid Chromatographic Determination of Ivermectin in Feed at the 2-PPM Level: Interlaboratory Study

1994 ◽  
Vol 77 (6) ◽  
pp. 1353-1358 ◽  
Author(s):  
David W Fink
Keyword(s):  
Solid Phase ◽  
Chromatographic Determination ◽  
Interlaboratory Study ◽  
Coefficients Of Variation ◽  
Significant Difference ◽  
The Individual ◽  
Liquid Chromatographic ◽  
Medicated Feeds ◽  
Ppm Level

Abstract An analytical method for the determination of ivermectin in feed at the 2 ppm level was evaluated in an interlaboratory study involving 4 laboratories. The method is based on liquid chromatographic measurement following sample preparation by adsorption chromatography on alumina and solid-phase extraction techniques. Each laboratory analyzed 2 complete, final, finished medicated feeds and the corresponding control feeds used in their preparation. In addition, they also measured recoveries in fortified feeds covering 50–150% of the 2 ppm ivermectin use concentration. The mean recoveries from the replicate analyses reported by the laboratories ranged from 90 to 110% and all coefficients of variation (CVs) were less than 4.5%. No significant interferences were found in the control feeds. The pooled distribution of all the individual analytical results (n = 100) gave a mean recovery of 100%, a recovery range of 90–111%, and an overall CV of 5.5%. Resolution of the total variance into its 2 components gave a withinlaboratory CV of 4.1% and a between-laboratories CV of 3.4%. There was no significant difference in recoveries among laboratories, days, concentrations, and feed base or between fortified and medicated feeds (P > 0.2).

scholarly journals Liquid Chromatographic Determination of Ivermectin in Feed

1998 ◽  
Vol 81 (4) ◽  
pp. 869-872 ◽  
Author(s):  
Stephen J Doherty ◽  
Allen Fox ◽  
David W Fink
Keyword(s):  
Solid Phase ◽  
Chromatographic Determination ◽  
Phase Extraction ◽  
Coefficients Of Variation ◽  
Significant Difference ◽  
Liquid Chromatographic Determination ◽  
Chromatographic Measurement ◽  
Liquid Chromatographic ◽  
Medicated Feeds

Abstract An analytical method for determining ivermectin in feed at 0.50- 3 ppm is presented. The method is based on liquid chromatographic measurement after sample preparation by adsorption chromatography on alumina and solid-phase extraction. Two complete, final, finished medicated feeds and the corresponding control feeds used in their preparation were analyzed. Recoveries from feeds fortified at 50-150% of the 2 ppm ivermectin use concentration also were determined. Mean recoveries from replicate analyses ranged from 90 to 100%, and coefficients of variation (CVs) were less than 4.5%. No significant interferences were found in control feeds. The pooled distribution of individual analytical results (n = 100) gave a mean recovery of 100%, a recovery range of 90-111%, and an overall CV of 5.5%. Resolution of the total variance into its 2 components gave a withinlaboratory CV of 4.1% and a between-laboratory CV of 3.4%. There was no significant difference in recoveries among laboratories, days, concentrations, and feed base or between fortified and medicated feeds (P > 0.2)

Gas Chromatographic Determination of Captan, Folpet, and Captafol Residues in Tomatoes, Cucumbers, and Apples Using a Wide-Bore Capillary Column: Interlaboratory Study

1991 ◽  
Vol 74 (5) ◽  
pp. 830-835 ◽  
Author(s):  
Dalia M Gilvydis ◽  
Stephen M Walters
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Capillary Column ◽  
Chromatographic Determination ◽  
Interlaboratory Study ◽  
Electron Capture Detection ◽  
Coefficients Of Variation ◽  
Capillary Column Gas Chromatography ◽  
Ppm Level

Abstract An interlaboratory study of the determination of captan, folpet, and captafol in tomatoes, cucumbers, and apples was conducted by 4 laboratories using wide-bore capillary column gas chromatography with electron capture detection. The 3 fungicides were determined using the Luke et al. multlresidue method modified to Include additional solvent elutlon in the optional Florisll column cleanup step used with this method. The crops were fortified with each fungicide at 3 levels per crop. Mean recoveries ranged from 86.2% for a 25.1 ppm level of captan in apples to 115.4% for a 0.288 ppm level of captafol In apples. Interlaboratory coefficients of variation ranged from 3.4% (24.7 ppm folpet) to 9.7% (0.243 ppm captafol) for tomatoes; from 2.8% (2.0 ppm captafol) to 8.2% (24.8 ppm captan) for cucumbers; and from 1.5% (0.234 ppm folpet) to 22.1% (0.266 ppm captafol) for apples.

Gas-Liquid Chromatographic Determination of Mirex and Photomirex in the Presence of Poly chlorinated Biphenyls: Interlaboratory Study

1980 ◽  
Vol 63 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Ross J Norstrom ◽  
Henry T Won ◽  
Micheline Van Hove Holdrinet ◽  
Patrick G Calway ◽  
Caroline D Naftel
Keyword(s):  
Chromatographic Determination ◽  
Interlaboratory Study ◽  
Gas Liquid Chromatography ◽  
Coefficients Of Variation ◽  
Fuming Nitric Acid ◽  
Liquid Chromatographic Determination ◽  
Repeatability And Reproducibility ◽  
Concentrated Sulfuric Acid ◽  
Liquid Chromatographic

Abstract Mirex and photomirex (8-monohydromirex) were separated from polychlorinated biphenyls (PCBs) and other aromatic compounds by nitration with fuming nitric acid-concentrated sulfuric acid and removal of nitro-PCBs on an alumina microcolumn; the compounds were then determined by gas-liquid chromatography. Recoveries of Mirex and photomirex were 102±8 and 104±5%, respectively, from standard solutions which had a PCB-to-Mirex and photomirex ratio of 1000. Recoveries from fortified, uncontaminated samples of sediment, fish, and eggs averaged 93±7 and 92±3% for Mirex and photomirex, respectively. The coefficients of variation for repeatability and reproducibility averaged 8 and 15%, respectively, in an interlaboratory study conducted by 4 laboratories using extracts of naturally contaminated substrates (sediment, carp, eel, and gull egg). Levels of Mirex in the samples ranged from 0.1 to 8 mg/kg, and levels of PCB ranged from 0.5 to 166 mg/kg.

Liquid Chromatographic Determination and Liquid Chromatographic-Thermospray Mass Spectrometric Confirmation of Nicarbazin in Chicken Tissues: Interlaboratory Study

1993 ◽  
Vol 76 (2) ◽  
pp. 420-423 ◽  
Author(s):  
Mary G Leadbetter ◽  
Jean E Matusik ◽  
◽  
W W Koscinski ◽  
M G Leadbetter ◽  
...  
Keyword(s):  
Chromatographic Determination ◽  
Interlaboratory Study ◽  
Ultraviolet Detection ◽  
Tissue Extracts ◽  
Muscle Tissues ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Thermospray Mass Spectrometry ◽  
Ppm Level

Abstract The U.S. Food and Drug Administration sponsored an interlaboratory study of a liquid chromatographic determination with ultraviolet detection of nicarbazin in chicken liver and muscle tissues. The method determined the 4,4’-dinitrocarbanilide(DNC) portion of nicarbazin. The interlaboratory study of the determinative method was successful for nicarbazin at the 4 ppm level. Results showed good reproducibility for the fortified liver and muscle samples. Mean interlaboratory recoveries and percent coefficients of variation at about 4 ppm were 87.1 and 10.9%, respectively, for muscle and 87.4 and 7.5%, respectively, for liver. The interlaboratory analyses of the dosed liver and muscle tissues produced concentration levels similar to those obtained by the sponsor. The confirmatory procedure, which identified DNC in purified tissue extracts, used liquid chromatography-thermospray/mass spectrometry. The confirmatory procedure was successfully evaluated by one FDA laboratory.

scholarly journals Liquid Chromatographic Determination of Mebendazole and its Metabolites, Aminomebendazole and Hydroxymebendazole, in Eel Muscle Tissue

1996 ◽  
Vol 79 (3) ◽  
pp. 645-651 ◽  
Author(s):  
Christiaan A J Hajee ◽  
Nel Haagsma
Keyword(s):  
Muscle Tissue ◽  
Mobile Phase ◽  
Solid Phase ◽  
Chromatographic Determination ◽  
Extraction Column ◽  
Phase Extraction ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract An analytical method is presented for liquid chromatographic (LC) determination of mebendazole (MBZ), hydroxymebendazole (MBZ-OH), and aminomebendazole (MBZ-NH2) in eel muscle tissue. Muscle tissue is extracted with ethyl acetate at pH 7.5. After addition of n-hexane, the extract is cleaned up and concentrated on an aminopropyl solid-phase extraction column. The test solutions are analyzed isocratically on a ChromSpher B LC column with acetonitrile–phosphate buffer, pH 6.2, as mobile phase. Limits of detection and quantitation were 0.7 and 1.1 ¼g/kg, respectively, for MBZOH; 1.4 and 2.3 ¼g/kg, respectively, for MBZ; and 1.5 and 2.1 ¼g/kg, respectively, for MBZ-NH2. Interand intraday coefficients of variation were 3.5 and 3.4%, respectively, for MBZ-OH; 2.5 and 3.1%, respectively, for MBZ; and 5.8 and 4.8%, respectively, for MBZ-NH2. Mean recoveries were 90% for MBZ, 74% for MBZ-NH2, and 92% for MBZ-OH. A linear range of applicability of at least 10–1000 ¼g/kg was found for each analyte. Incurred MBZ-NH2 (181.3 ¼g/kg) was identified in eel muscle tissue apart from MBZ (23.7 ¼g/kg) after 48 h exposure ina treatment bath containing MBZ at 1 mg/L.

Liquid Chromatographic Determination of Carhadox in Complete Feeds, Premixes, and Concentrates: Interlaboratory Study

1988 ◽  
Vol 71 (3) ◽  
pp. 484-490
Author(s):  
René M L Aerts ◽  
Geziena A Werdmuller
Keyword(s):  
Chromatographic Determination ◽  
Interlaboratory Study ◽  
Alumina Column ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
A Minor ◽  
Liquid Chromatographic ◽  
Feed Samples

Abstract A liquid chromatographic (LC) method previously published for the determination of carbadox in finished feeds and premixes was slightly modified and tested in an interlaboratory study. The feed samples are extracted with methanol-acetonitrile (50 + 50) after wetting with water. The extracts are purified over a short alumina column. An aliquot of the eluate is analyzed with reverse phase liquid chromatography with ultraviolet detection. Before the actual interlaboratory study, a prestudy with 2 familiarization feed samples was performed. For the interlaboratory study, 2 series of meal and pelleted samples were prepared with carbadox from different suppliers. Eight collaborating laboratories received 6 feed samples previously milled and ground and 4 pelleted samples which had to be ground by the collaborator's in-house method. Collaborators also received 3 carbadox concentrates (about 10% w/w) and 4 premix samples derived from the concentrates (about 1% w/w). Coefficients of variation under reproducibility conditions were 8.3% for meal samples and 4.9% for pellets. A minor but significant effect was noted for the influence of pelleting temperature on the carbadox content. A minor and insignificant effect was observed for the influence of the milling and grinding procedure on the carbadox content. Alumina cleanup of 1% premixes was not essential, although the resulting chromatograms were cleaner. A slight difference in reproducibility was observed with concentrates (10%) when 0.2 or 0.5 g sample size was used, although the average carbadox concentration found was the same. For premixes and concentrates, coefficients of variation under reproducibility conditions were low, ranging from 2.9 to 7.5%.

Liquid Chromatographic Determination of Ivermectin in Bovine Milk: Interlaboratory Study

1992 ◽  
Vol 75 (4) ◽  
pp. 747-750 ◽  
Author(s):  
Philip James Kijak
Keyword(s):  
Bovine Milk ◽  
Chromatographic Determination ◽  
Interlaboratory Study ◽  
Marker Compound ◽  
Lactating Dairy Cows ◽  
Coefficients Of Variation ◽  
Laboratory Trial ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A laboratory trial was completed for an analytical method that can quantitate the marker residue of ivermectin, 22,23-dihydroavermectin B1a, in bovine milk at 1 ng/mL Currently, ivermectin is not approved for use in lactating dairy cows. In this method, the ivermectin residues are isolated from the milk matrix by a series of liquid-liquid extractions. A fluorescent derivative of the marker compound is prepared and then quantified by liquid chromatography with fluorescence detection. The interlaboratory study was successfully completed by using dosed milk and milk fortified with marker residue at 1,2, and 4 ng/mL. The average recoveries by the 3 participating laboratories were 87,59, and 95% at 1 ng/mL; 90,61, and 96% at 2 ng/mL; and 90,73, and 99% at 4 ng/mL. The concentrations of the marker residue in the dosed milk were 4.3, 3.7, and 4.7 ng/mL; coefficients of variation were 4.0,24.8, and 5.9%, respectively.

Collaborative Study of the Gas-Liquid Chromatographic Determination of Coumarin (1,2-Benzopyrone) in Wine

1976 ◽  
Vol 59 (4) ◽  
pp. 780-782
Author(s):  
Randolph H Dyer ◽  
Glenn E Martin
Keyword(s):  
Collaborative Study ◽  
Chromatographic Determination ◽  
Chloroform Extract ◽  
Gas Liquid Chromatography ◽  
Individual Values ◽  
Significant Difference ◽  
Liquid Chromatographic Determination ◽  
The Individual ◽  
Liquid Chromatographic

Abstract The determination of coumarin in wine by using gas-liquid chromatography of a chloroform extract was collaboratively studied. Eleven collaborators analyzed 6 samples: 3 containing 4.0 mg coumarin/L, 2 containing 8.0, and 1 containing 0.0. When the triplicate and duplicate recoveries for the 4.0 and 8.0 levels were averaged and treated singly for the collaborators, there was no statistically significant difference in the accuracy between the 2 levels. However, the accuracy for the 4.0 level was much better than that for the 8.0 level: 100.0 vs. 105.9%. An analysis of the individual values showed no significant differences among collaborator means at the 4.0 level, while there was a significant difference among means at the 8.0 level. All collaborators were within the allowable score limits in the ranking test. The method was adopted as official first action.

Liquid Chromatographic Determination of Zoalene in Medicated Feeds

1984 ◽  
Vol 67 (5) ◽  
pp. 861-862 ◽  
Author(s):  
John Morawski ◽  
Glenn Kyle
Keyword(s):  
Colorimetric Method ◽  
Chromatographic Determination ◽  
Activated Alumina ◽  
Reverse Phase ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Aoac Official ◽  
Liquid Chromatographic ◽  
Medicated Feeds

Abstract A rapid, reliable separation and quantitation of zoalene (3,5-dinitroo-toluamide) from feeds is accomplished by using reverse phase liquid chromatography (LC) and ultraviolet detection. An extraction technique which is similar to the present AOAC official colorimetric method is used before chromatographic analysis. This extraction is followed by an activated alumina cleanup and LC to separate zoalene from feed matrix. The methodology was applied to a variety of spiked feed matrices, and yielded good recoveries. Liquid chromatographic results were shown to correlate with colorimetric determinations.

Sign in / Sign up

Export Citation Format

Share Document