Determination of Ractopamine Hydrochloride in Swine, Cattle, and Turkey Feeds by Liquid Chromatography with Coulometric Detection

1994 ◽  
Vol 77 (4) ◽  
pp. 840-847 ◽  
Author(s):  
Michael P Turberg ◽  
Thomas D Macy ◽  
Jerry J Lewis ◽  
Mark R Coleman
Keyword(s):  
Solid Phase ◽  
Reversed Phase ◽  
Free Base ◽  
Coulometric Detection ◽  
Solid Phase Extraction Cartridge ◽  
Coefficients Of Variation ◽  
Ractopamine Hydrochloride ◽  
Cattle Feeds ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method is described for the determination of ractopamine hydrochloride (LY31537) in swine, turkey, and cattle feeds in the 1.25–100 ppm range and in swine supplement at 100 ppm. Feed samples were extracted with acidified methanol. An aliquot of the feed extract was diluted with water and buffered to pH 10.5 ± 0.5 with sodium carbonate to convert ractopamine hydrochloride to a free base. The free base was extracted from the buffered sample with ethyl acetate. The extract was further purified on an acid-washed, silica solid-phase extraction cartridge. After conversion of the free base back to the salt form with pH 4.5 buffer, analytical separation and quantitation of ractopamine hydrochloride were accomplished on IBM phenyl and Whatman ODS reversed-phase columns with coulometric detection at +600 mV. Mean daily recovery levels ranged from 85 to 100% for feeds fortified at 1.25 to 100 ppm. The coefficients of variation ranged from 1 to 6% for feeds fortified at 2.5 to 100 ppm.

Determination of Ractopamine Hydrochloride in Swine and Turkey Tissues by Liquid Chromatography with Coulometric Detection

1995 ◽  
Vol 78 (6) ◽  
pp. 1394-1402 ◽  
Author(s):  
Michael P Turberg ◽  
Thomas D Macy ◽  
Jerry J Lewis ◽  
Mark R Coleman
Keyword(s):  
Limit Of Detection ◽  
Solid Phase ◽  
Free Base ◽  
Coulometric Detection ◽  
Solid Phase Extraction Cartridge ◽  
Coefficients Of Variation ◽  
Swine Liver ◽  
Ractopamine Hydrochloride ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method is described for determination of ractopamine hydrochloride (LY031537) in swine and turkey tissues. Liver, kidney, muscle, and fat samples were homogenized in methanol. An aliquot of the extract was evaporated, diluted with water, and buffered to pH 10.5 ± 0.5 with sodium carbonate to convert ractopamine hydrochloride to a free base. The free base was extracted from the buffered sample with ethyl acetate. The extract was further purified on a Bond Elut acid-washed silica solid-phase extraction cartridge. After converting the free base back to the salt form with pH 4.5 buffer, analytical separation and quantitation of ractopamine hydrochloride was performed on an IBM C18 column with coulometric detection at +600 mV. The limit of detection of the method was approximately 0.5 ppb as determined in swine liver. Overall recovery levels ranged between 75 and 100% for samples of liver, kidney, muscle, and fat fortified at 1 to 100 ppb. The coefficients of variation ranged from 2 to 18% for samples fortified at 1 to 100 ppb.

scholarly journals Determination of Penicillin G in Feeds by Liquid Chromatography with Solid-Phase Extraction

2005 ◽  
Vol 88 (3) ◽  
pp. 679-683 ◽  
Author(s):  
Matthew J Gramse ◽  
Paul E Jacobson
Keyword(s):  
Liquid Chromatography ◽  
Solid Phase Extraction ◽  
Solid Phase ◽  
Reversed Phase ◽  
Penicillin G ◽  
Phase Extraction ◽  
Solid Phase Extraction Cartridge ◽  
Relative Standard ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method was developed for the determination of penicillin G in feeds. The method involves extraction of penicillin G with methanol, concentration under a stream of nitrogen, and cleanup using Phenomenex Strata-X solid-phase extraction cartridge. Analyte separation and quantification were achieved by gradient reversed-phase liquid chromatography and ultraviolet absorbance at 230 nm. Average spike recoveries for samples prepared at 3 spiking levels (25, 50, and 200 g/ton) were 96.3, 92.1, and 88.6%, respectively. The overall method precision at each of the 3 spiking levels was ≤5.39% relative standard deviation. The limits of detection and quantititation (g/ton formulation) were 3.89 and 13.0 g/ton, respectively.

scholarly journals Determination of Amoxicillin in Catfish and Salmon Tissues by Liquid Chromatography with Precolumn Formaldehyde Derivatization

1996 ◽  
Vol 79 (2) ◽  
pp. 389-396 ◽  
Author(s):  
Catharina Y W Ang ◽  
Wenhong Luo ◽  
Eugene B Hansen ◽  
James P Freemana ◽  
Harold C Thompson
Keyword(s):  
Muscle Tissue ◽  
Fluorescence Detection ◽  
Solid Phase ◽  
Reversed Phase ◽  
Liquid Extraction ◽  
Liquid Liquid Extraction ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic ◽  
Reversed Phase Lc

Abstract A liquid chromatographic (LC) method with fluorescence detection was developed for analysis of amoxicillin in catfish and salmon tissues. The tissue was extracted with phosphate buffer (pH 4.5), followed by trichloroacetic acid (TCA) precipitation of proteins and solid-phase (C18) extraction. Trace amounts of nonpolar interfering substances present after solid-phase extraction were removed by ether liquid-liquid extraction. The extract was reacted with formaldehyde and TCA at 100°C for 30 min. A fluorescent derivative was extracted with ether, concentrated, and analyzed by reversed phase LC with fluorescence detection. Average recoveries of amoxicillin spiked at 2.5-20 ppb were >80% for catfish and >75% for salmon muscle tissue, with coefficients of variation of <6%. Limits of detection (LOD) and quantitation (LOQ) for catfish tissue were 0.5 and 1.2 ppb, respectively. LOD and LOQ for salmon muscle tissue were 0.8 and 2.0 ppb, respectively.

scholarly journals Determination of Ceftiofur in Bovine Milk by Liquid Chromatography

1996 ◽  
Vol 79 (4) ◽  
pp. 844-847 ◽  
Author(s):  
Patrick J Mcneilly ◽  
Valerie B Reeves ◽  
E J Ian Deveau
Keyword(s):  
Ammonium Acetate ◽  
Methanol Extract ◽  
Solid Phase ◽  
Bovine Milk ◽  
Reversed Phase ◽  
Acetate Solution ◽  
Coefficients Of Variation ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic

Abstract A liquid chromatographic procedure is described for determination of ceftiofur (CEF) residues in milk. Milk samples were diluted with ammonium acetate solution and extracted on a C18 solid-phase extraction (SPE) column. After the analyte was eluted from the SPE column with methanol, extract volumes were reduced under nitrogen, diluted to 2.0 mL with acetate buffer, and filtered. CEF was determined after separation of milk components by reversed-phase chromatography with UV detection at 293 nm. Recoveries of CEF from bovine milk fortified at 25,50, and 100 ppb were 86.1,90.8, and 92.0%, respectively, with coefficients of variation (CVs) of 6.4, 7.3, and 3.9%, respectively. Values of CEF obtained from analysis of milk containing 2 levels of biologically incurred residues were 26.1 and 67.3 ppb with CVs of 3.8 and 4.4%, respectively. The limits of detection and quantitation were estimated to be 4 and 7 ppb, respectively.

scholarly journals Analytical Determination of Virginiamycin Drug Residues in Edible Porcine Tissues by LC-MS with Confirmation by LC-MS/MS

2009 ◽  
Vol 92 (1) ◽  
pp. 329-339 ◽  
Author(s):  
Joe Boison ◽  
Stephen Lee ◽  
Ron Gedir
Keyword(s):  
Solid Phase ◽  
Minor Component ◽  
Analytical Determination ◽  
Porcine Liver ◽  
Solid Phase Extraction Cartridge ◽  
Muscle Tissues ◽  
Dried Extract ◽  
A Minor ◽  
Liquid Chromatographic

Abstract A liquid chromatographic-mass spectrometric (LC-MS) method was developed and validated for the determination and confirmation of virginiamycin (VMY) M1 residues in porcine liver, kidney, and muscle tissues at concentrations 2 ng/g. Porcine liver, kidney, or muscle tissue is homogenized with methanolacetonitrile. After centrifugation, the supernatant is diluted with phosphate buffer and cleaned up on a C18 solid-phase extraction cartridge. VMY in the eluate is partitioned into chloroform and the aqueous upper layer is removed by aspiration. After evaporating the chloroform in the residual mixture to dryness, the dried extract is reconstituted in mobile phase and VMY is quantified by LC-MS. Any samples eliciting quantifiable levels of VMY M1 (i.e., at concentrations 2 ng/g) are subjected to confirmatory analysis by LC-MS/MS. VMY S1, a minor component of the VMY complex, is monitored but not quantified or confirmed.

scholarly journals Rapid Determination of Ampicillin in Bovine Milk by Liquid Chromatography with Fluorescence Detection

1997 ◽  
Vol 80 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Catharina Y W Ang ◽  
Luo Wenhong
Keyword(s):  
Fluorescence Detection ◽  
Rapid Determination ◽  
Bovine Milk ◽  
Skim Milk ◽  
Reversed Phase ◽  
Coefficients Of Variation ◽  
Whole Milk ◽  
Liquid Chromatographic ◽  
Clear Supernatant

Abstract A rapid and sensitive liquid chromatographic (LC) method was developed for the determination of am- picillin residues in raw bovine milk, processed skim milk, and pasteurized, homogenized whole milk with vitamin D. Milk samples were deprote- inized with trichloroacetic acid (TCA) and acetonitrile. After centrifugation, the clear supernatant was reacted with formaldehyde and TCA under heat. The major fluorescent derivative of ampicillin was then determined by reversed-phase LC with fluorescence detection. Average recoveries of ampicillin fortified at 5,10, and 20 ppb (ng/mL) were all >85% with coefficients of variation <10%. Limits of detection ranged from 0.31 to 0.51 ppb and limits of quantitation, from 0.66 to 1.2 ppb. After appropriate validation, this method should be suitable for rapid analysis of milk for ampicillin residues at the tolerance level of 10 ppb.

scholarly journals Preparative Method for Isolating α-Zearalenol and Zearalenone Using Extracting Disk

1999 ◽  
Vol 82 (1) ◽  
pp. 90-94 ◽  
Author(s):  
George M Ware ◽  
Yuhong Zhao ◽  
Shia S Kuan ◽  
Allen S Carman
Keyword(s):  
Limit Of Detection ◽  
Solid Phase ◽  
Control Sample ◽  
Preparative Method ◽  
Reversed Phase ◽  
Fluorescence Detector ◽  
Coefficients Of Variation ◽  
Limit Of Quantitation ◽  
Standard Calibration ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method is described for the determination of zearalenol and zearalenone in corn. Zearalenol and zearalenone are extracted from corn with methanol–water (1+1) and cleaned up using a solid-phase extraction (SPE) disk, separatedon a reversed-phase analytical column, and detected with a fluorescence detector. The SPE disk concentrated and cleanly separated zearalenol and zearalenone from sample interferences. Standard calibration curves for zearalenol and zearalenone for the concentration range 25–500 ng/mL were linear. The small extract disk had a column capacity equivalent to 1 g extracted corn. Zearalenol and zearalenone were added at levels ranging from 10 to 2000 ng/g to a control sample that contained no detectable levels of zearalenol and zearalenone. Both toxins were recovered from spiked samples at 106.3 and 103.8%, with coefficients of variation of 7.6 and 13.0%, respectively. The method has an estimated reliable limit of detection and limit of quantitation around 10 and 40 ng/g for each toxin, respectively.

scholarly journals Assay of Florfenicol in Swine Feed: Interlaboratory Study

2009 ◽  
Vol 92 (1) ◽  
pp. 340-347 ◽  
Author(s):  
John M Hayes ◽  
Rosalia Gilewicz ◽  
Keith Freehauf ◽  
Mary Fetter
Keyword(s):  
Solid Phase ◽  
Reversed Phase ◽  
Interlaboratory Study ◽  
Method Performance ◽  
Simple Method ◽  
Matrix Interferences ◽  
Solid Phase Extraction Cartridge ◽  
Phase Liquid ◽  
Pellet Form ◽  
Liquid Chromatographic

Abstract Nuflor (florfenicol) Premix for Swine was recently approved by the U.S. Food and Drug Administration (FDA) for control of swine respiratory disease (SRD). A simple method for the assay of florfenicol in Type C medicated swine feeds was recently evaluated as part of a 4-laboratory study. Florfenicol is extracted from ground feed with acetonitrilewater by shaking and sonication. An Envi-Carb solid-phase extraction cartridge is used to clean up the extract, retaining matrix interferences while allowing florfenicol to elute. The collected eluent is diluted and injected into a reversed-phase liquid chromatographic system. Samples are quantitated by external standard analysis versus multilevel calibration solutions. The procedure is suitable for the quantification of swine feeds in mash or pellet form medicated with 100300 mg/kg florfenicol. The interlaboratory study was conducted according to Guidance 136 issued by the FDA Center for Veterinary Medicine. The feeds used to evaluate method performance represented different feed compositions (starter and finisher) and manufacturers. The sponsor and 3 independent laboratories obtained mean recoveries (SD) from fortified swine feeds of 100.7 (2.0), 99.6 (2.8), 98.8 (1.4), and 99.3 (1.7), respectively. Excellent agreement of the results of the assay of blind samples of commercial swine mash and pelleted feeds between laboratories demonstrates that the method is rugged and reproducible.

Determination of Acesulfam-K in Foods

1993 ◽  
Vol 76 (2) ◽  
pp. 268-274 ◽  
Author(s):  
Jacques Prodolliet ◽  
Milene Bruelhart
Keyword(s):  
Fruit Juice ◽  
Soft Drink ◽  
Food Additives ◽  
Reversed Phase ◽  
Uv Absorbance ◽  
Phase Detection ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method was evaluated for the determination of the intense sweetener acesulfam-K in tabletop sweetener, candy, soft drink, fruit juice, fruit nectar, yogurt, cream, custard, chocolate, and biscuit commercial preparations. Samples are extracted or simply diluted with water and filtered. Complex matrixes need a clarification step with Carrez solutions. An aliquot of the extract is analyzed on a reversed-phase μBondapak C18 column using 0.0125M KH2PO4 (pH 3.5)-acetonitrile (90 + 10) as mobile phase. Detection is performed by UV absorbance at 220 nm. Recoveries ranged from 95.2 to 106.8%. With one exception, all analyzed values were within ±15% of the declared levels. The repeatabilities and the repeatability coefficients of variation were, respectively, 0.37 mg/100 g and 0.98% for products containing less than 40 mg/100 g acesulfam-K and 2.43 mg/100 g and 1.29% for other products. The same procedure also allowed detection of many food additives or natural constituents, such as other intense sweeteners, organic acids, and alkaloids, in a single run without interfering with acesulfam-K. The method is simple, rapid, precise, and sensitive; therefore, it is suitable for routine analyses.

Determination of Aspartame and Its Major Decomposition Products in Foods

1993 ◽  
Vol 76 (2) ◽  
pp. 275-282 ◽  
Author(s):  
Jacques Prodolliet ◽  
Milene Bruelhart
Keyword(s):  
Soft Drink ◽  
Food Additives ◽  
Reversed Phase ◽  
Food Samples ◽  
Phase Detection ◽  
Decomposition Products ◽  
Coefficients Of Variation ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic

Abstract A liquid chromatographic procedure already evaluated in a preceding study for the analysis of acesulfam-K is also suitable for the determination of the intense sweetener aspartame in tabletop sweetener, candy, fruit beverage, fruit pulp, soft drink, yogurt, cream, cheese, and chocolate preparations. The method also allows the determination of aspartame’s major decomposition products: diketopiperazine, aspartylphenylalanine, and phenylalanine. Samples are extracted or diluted with water and filtered. Complex matrixes are centrifuged or clarified with Carrez solutions. An aliquot of the extract is analyzed on a reversed-phase μBondapak C18 column using 0.0125M KH2P04 (pH 3.5)-acetonitrile ([85 + 15] or [98 + 2]) as mobile phase. Detection is performed by UV absorbance at 214 nm. Recoveries ranged from 96.1 to 105.0%. Decomposition of the sweetener was observed in most food samples. However, the total aspartame values (measured aspartame + breakdown products) were within -10% and +5% of the declared levels. The repeatabilities and the repeatability coefficients of variation were, respectively, 1.00 mg/100 g and 1.34% for products containing less than 45 mg/100 g aspartame and 4.11 mg/100 g and 0.91 % for other products. The technique is precise and sensitive. It enables the detection of many food additives or natural constituents, such as other intense sweeteners, organic acids, and alkaloids, in the same run without interfering with aspartame or its decomposition products. The method is consequently suitable for quality control or monitoring.

Sign in / Sign up

Export Citation Format

Share Document