Liquid Chromatographic Determination and Gas Chromatographic-Mass Spectrometric Confirmation of Lasalocid Sodium in Bovine Liver: Interlaboratory Study

1989 ◽  
Vol 72 (4) ◽  
pp. 581-584 ◽  
Author(s):  
David R Newkirk ◽  
Charlie J Barnes
Keyword(s):  
Bovine Liver ◽  
Chromatographic Determination ◽  
Food Samples ◽  
Mass Spectrometric ◽  
Metabolic Marker ◽  
Interlaboratory Studies ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Ppm Level ◽  
Chromatographic Mass

Abstract An analytical method has been developed that can reliably measure the metabolic marker residue of lasalocid. The method monitors this marker residue in food samples to ensure that the total residue of toxicological concern is not being exceeded. Interlaboratory studies of the liquid chromatographic determinative procedure and the gas chromatographic/mass spectrometric confirmatory procedure for lasalocid sodium at the 0.7 ppm level and higher were successful.

Liquid Chromatographic Determination and Gas Chromatographic-Mass Spectrometric Confirmation of Lasalocid Sodium in Bovine Liver: Interlaboratory Study

1989 ◽  
Vol 72 (4) ◽  
pp. 584-586
Author(s):  
Lesley R Frank ◽  
Charlie J Barnes
Keyword(s):  
Bovine Liver ◽  
Chromatographic Determination ◽  
Interlaboratory Study ◽  
Tissue Samples ◽  
Coefficients Of Variation ◽  
Chicken Skin ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Good Agreement ◽  
Chromatographic Mass

Abstract The U.S. Food and Drug Administration (FDA) sponsored an interlaboratory study of a liquid chromatographic determinative procedure for lasalocid sodium in chicken skin with adhering fat. Four laboratories analyzed 35 dosed tissue samples and 82 fortified tissue samples containing lasalocid at levels ranging from 0.1 to 0.6 ppm. Samples were homogenized with acetonitrile, washed with hexane, and partitioned into the mobile phase prior to analysis liquid chromatography with fluorescence detection. The results of the interlaboratory study showed good reproducibility for fortified samples. Fortification levels, average recoveries, and interlaboratory percent coefficients of variation were as follows: 0.6 ppm, 0.57 ppm, and 9.7; 0.3 ppm, 0.25 ppm, and 9.1; and 0.15 ppm, 0.14 ppm, and 7.0, respectively. Data for analysis of the dosed tissue also showed good agreement among the laboratories.

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.

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).

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.

Gas-Liquid Chromatographic Determination of Chlorinated Norbornene Derivatives in Fish

1978 ◽  
Vol 61 (1) ◽  
pp. 26-31
Author(s):  
Martin P Yurawecz ◽  
John A G Roach
Keyword(s):  
Petroleum Ether ◽  
Mississippi River ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
Chlorinated Pesticides ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Norbornene Derivatives ◽  
Ppm Level

Abstract 1,2,3,4,7,7 - Hexachloro - 2,5 - norbornadiene (I), 1,2,3,4,5 - endo,7,7 - heptachloro - 2 - norbornene (II), and l,2,3,4,7,7-hexachloro-5,6-erecfoepoxy- 2-norbornene (III) have been identified as contaminants in Mississippi River fish by combined gas-liquid chromatography (GLC)- mass spectrometry. The method used to determine residues of these compounds, which are associated with production of the pesticide endrin, is similar to the AOAC multiresidue method for chlorinated pesticides. The residues are extracted from the sample with acetonitrile, transferred to petroleum ether, and chromatographed on a Florisil column. Compounds I and II are eluted from the Florisil with petroleum ether and compound III is eluted with ethyl ether-petroleum ether (6+94). The concentrated eluates are analyzed by using electron capture GLC. The method provides adequate recoveries of all 3 chlorinated norbornene derivatives and allows quantitation at or below the 0.05 ppm level in fish with a 20 mg sample equivalent injection.

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