Multiresidue Method for Isolation and Liquid Chromatographic Determination of Seven Benzimidazole Anthelmintics in Milk

1989 ◽  
Vol 72 (5) ◽  
pp. 739-741 ◽  
Author(s):  
Austin R Long ◽  
Lily C Hsieh ◽  
Marsha S Malbrough ◽  
Charles R Short ◽  
Steven A Barker
Keyword(s):  
Methylene Chloride ◽  
Correlation Coefficients ◽  
Chromatographic Determination ◽  
Multiresidue Method ◽  
Milk Samples ◽  
Photodiode Array ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Benzimidazole Anthelmintics

Abstract A multiresidue method for the isolation and liquid chromatographic determination of 7 benzimidazole anthelmintics (thiabendazole, oxfendazole, para-hydroxyfenbendazole, fenbendazole sulfone, mebendazole, albendazole, and fenbendazole) in milk is presented. Blank or benzimidazole-spiked milk samples (0.5 mL) were blended with octadecylsilyl (C-18, 18% load, end-capped) derivatized silica packing material. A column made from the C-18/milk matrix was first washed with hexane (8 mL), and then the benzimidazoles were eluted with methylene chloride-ethyl acetate (1 + 2, v/v; 8 mL). The eluate contained benzimidazole analytes which were free from interfering compounds as determined by UV detection (photodiode array, 290 nm). Correlation coefficients of standard curves for individual benzimidazoles isolated from spiked samples were linear (0.989 ± 0.003 to 0.998 ± 0.001) with recoveries ranging from 70 ± 9% to 107 ± 2% for the concentration range (62.5-2000 ng/mL) examined. The inter- assay variabilities ranged from 4 ± 1% to 9 ± 7% with intra-assay variabilities of 3-6%.

Matrix Solid Phase Dispersion Isolation and Liquid Chromatographic Determination of Five Benzimidazole Anthelmintics in Fortified Beef Liver

1990 ◽  
Vol 73 (6) ◽  
pp. 860-863 ◽  
Author(s):  
Austin R Long ◽  
Marsha S Malbrough ◽  
Lily C Hsieh ◽  
Charles R Short ◽  
Steven A Barker
Keyword(s):  
Solid Phase ◽  
Correlation Coefficients ◽  
Chromatographic Determination ◽  
Activated Alumina ◽  
Beef Liver ◽  
Liquid Chromatographic Determination ◽  
Internal Standardization ◽  
Liquid Chromatographic ◽  
Benzimidazole Anthelmintics

Abstract A multlresidue method for Isolation and liquid chromatographic determination of 5 benzimidazole anthelmintics (thiabendazole, oxfendazole, mebendazole, albendazole, and fenbendazole) in beef liver tissue is presented. Blank or benzlmldazole-fortlfled liver samples (0.5 g) were blended with octadecylsilyl derlvatlzed silica packing material (C18, 18% load, endcapped, 2 g). A column made from the C18/ liver matrix was first washed with hexane (8 ml_), following which the benzlmldazoles were eluted with acetonltrile. The acetonltrlle extract was then passed through an activated alumina column. The eluate contained benzimidazole analytes that were free from Interfering compounds as determined by UV detection (photodlode array, 290 nm). Correlation coefficients of standard curves for Individual benzlmldazoles Isolated from fortified samples, using internal standardization, were linear (0.996 ± 0.002 to 0.999 ± 0.001) with average relative percentage recoveries from 62.0 ± 6.7 to 86.8 ± 8.6% for the concentration range (100- 3200 ng/g) examined. The interassay variability was 7.0 ± 4.1 to 12.9 ± 10.2% with an Intra-assay variability from 2.2 to 4.0%.

Matrix Solid-Phase Dispersion (MSPD) Isolation and Liquid Chromatographic Determination of Oxytetracycline, Tetracycline, and Chlortetracycline in Milk

1990 ◽  
Vol 73 (3) ◽  
pp. 379-384 ◽  
Author(s):  
Austin R Long ◽  
Lily C Hsieh ◽  
Marsha S Malbrouh ◽  
Charles R Short ◽  
Steven A Barker
Keyword(s):  
Solid Phase ◽  
Correlation Coefficients ◽  
Chromatographic Determination ◽  
Average Percentage ◽  
Phase Dispersion ◽  
Fortified Milk ◽  
Photodiode Array ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A multlresldue method for the isolation and liquid chromatographic determination of oxytetracycline (OTC), tetracycline (TC), and chlortetracycllne (CTC) antibiotics In milk Is presented. Blank and tetracycline (OTC, TC, and CTC) fortified milk samples (0.5 mL) were blended with octadecylsllyl (C18, 40 /an, 18% load, endcapped, 2 g) derivatized silica packing material containing 0.05 g each of oxalic acid and dlsodlum ethylenedlamlnetetraacetlc. A column made from the C18/milk matrix was first washed with hexane (8 mL), following which the tetracyclines were eluted with ethyl acetate-acetonltrlle (1 + 3; v/v). The eluate contained tetracycline analytes that were free from Interfering compounds when analyzed by liquid chromatography with UV detection (photodiode array, 365 nm). Correlation coefficients of standards curves for Individual tetracycline isolated from fortified samples were linear (from 0.982 ± 0.009 to 0.996 ± 0.004) with average percentage recoveries from 63.5 to 93.3 for the concentration range (100,200,400,800,1600, and 3200 ng/ mL) examined. The Inter-assay variability ranged from 8.5 ± 2.4% to 20.7 ± 13.0% with an Intra-assay variability of 1.0- 9.3%.

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

scholarly journals Liquid Chromatographic Determination of Five Benzoylurea Insecticides in Fruit and Vegetables

1998 ◽  
Vol 81 (5) ◽  
pp. 1037-1042 ◽  
Author(s):  
Miguel Gamón ◽  
Adolfo Saez ◽  
Rosa Pelegrí ◽  
Inmaculada Peris ◽  
Josá G De La Cuadra ◽  
...  
Keyword(s):  
Solid Phase ◽  
Chromatographic Determination ◽  
Photodiode Array Detection ◽  
Photodiode Array ◽  
Array Detection ◽  
Liquid Chromatographic Determination ◽  
Benzoylurea Insecticides ◽  
Vegetables And Fruits ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method was developed to determine 5 benzoyl ureas—diflubenzuron, hexaflumuron, teflubenzuron, flufenozuron, and lufenuron—in peppers, tomatoes, eggplants, cucumbers, and oranges. Preparation of samples involve extraction with acetone and partitioning into dichloromethane-petroleum ether. A portion of this extract is cleaned up with a solid-phase extraction aminopropyl disposable column. With LC analysis using an RP-8-DB microbore column, acetonitrilewater (70 + 30, v/v) as mobile phase, and photodiode array detection at 254 nm, recovery and repeatability data were collected for the 5 benzoylureas on 4 vegetables and citrus in the range 0.04-2.0 mg/kg. Validated limits of detection and quantitation were 0.01 and 0.04 mg/kg, respectively. The method is reliable for routine analysis of vegetables and fruits

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.

scholarly journals Liquid chromatographic determination of glyphosate and aminomethylphosphonic acid residues in rapeseed with MS/MS detection or derivatization/fluorescence detection

2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Piotr Kaczyński ◽  
Bożena Łozowicka
Keyword(s):  
Liquid Chromatography ◽  
Fluorescence Detection ◽  
Correlation Coefficients ◽  
Chromatographic Determination ◽  
Triple Quadrupole ◽  
Ms Detection ◽  
Aminomethylphosphonic Acid ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

AbstractGlyphosate and AMPA determinations in rapeseed extracts by (a) liquid chromatography with triple quadrupole MS detection (LC-MS/MS), or (b) liquid chromatography with post-column OPA derivatization and fluorescence detection (LC-FLD) were developed. Mean recoveries for glyphosate and AMPA were (a) 88.8–95.0% and 82.1–86.1%, and (b) 70.8–74.1% and 62.4–72.6%. RSD were below (a) 11% and (b) 22%. Correlation coefficients were above 0.997 for both methods. LOD were 0.01 mg kg

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.

Liquid Chromatographic Determination of Depletion of Bithionol Sulfoxide and Its Two Major Metabolites in Bovine Milk

1987 ◽  
Vol 70 (5) ◽  
pp. 810-812
Author(s):  
Dominique Mourot ◽  
MichÈle Dagorn ◽  
Bernard Delepine
Keyword(s):  
Bovine Milk ◽  
Chromatographic Determination ◽  
Milk Samples ◽  
Lactating Cows ◽  
Holstein Friesian ◽  
Liquid Chromatographic Method ◽  
Reliable Detection ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method is described for determining bithionol sulfoxide and its metabolites, bithionol and bithionol sulfone, in milk. Samples are treated with HC1 to precipitate proteins and to permit extraction of bithionol sulfoxide in nonionized form. Tetrahydrofuran is added to the organic phase to facilitate extraction in diethyl ether; the dried residue is dissolved in chloroform, hexane, and sodium hydroxide and subjected to LC analysis. Residues of bithionol sulfoxide and its 2 metabolites were determined in milk of lactating cows. Holstein-Friesian dairy cows were administered a single oral dose of bithionol sulfoxide (50 mg/kg). Milk samples were analyzed with a reliable detection level of 0.025 pg/mL for each compound. Residues of bithionol sulfoxide and bithionol were detected during 30 and 16 milkings, respectively; bithionol sulfone was never present at detectable levels

scholarly journals Determination of Oxytetracycline, Tetracycline, and Chlortetracycline in Milk by Liquid Chromatography with Postcolumn Derivatization and Fluorescence Detection

1999 ◽  
Vol 82 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Angelina L S Pena ◽  
Celeste M Lino ◽  
Irene N Silveira
Keyword(s):  
Correlation Coefficients ◽  
Chromatographic Determination ◽  
Regulatory Agencies ◽  
Good Precision ◽  
Routine Surveillance ◽  
Surveillance Programs ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Postcolumn Derivatization

Abstract A multiresidue method for isolation and liquid chromatographic determination of oxytetracycline (OTC), tetracycline (TC), and chlortetracycline (CTC) in milk is presented. The sensitivity of the method is adequate to meet the needs of regulatory agencies. The European Community established 100 μg/kg as the maximum residue limit (MRL) in milk for TC, CTC, and OTC. Recoveries exceeded 80% for all tetracyclines at all levels, with good precision. Correlation coefficients of standards curves for individual tetracyclines isolated from fortified samples ranged from 0.991 for CTC to 0.998 for OTC. Other antibiotics that might interfere with analysis did notinterfere with elution times of OTC, TC, andCTC. The procedure is rapid, precise, and quantitative and requires minimal preparation andminimal use of organic solvents. It can beapplied to routine surveillance programs. We canprepare 10 samples for analysis in about 1.45 h.

Gas-Liquid Chromatographic Determination of Captan and Two Metabolites in Milk and Meat

1977 ◽  
Vol 60 (3) ◽  
pp. 679-681
Author(s):  
John H Onley
Keyword(s):  
Ethyl Acetate ◽  
Silica Gel ◽  
Chromatographic Determination ◽  
Gel Chromatography ◽  
Milk Samples ◽  
Liquid Chromatographic Determination ◽  
Meat Samples ◽  
Silica Gel Chromatography ◽  
Liquid Chromatographic

Abstract A gas-liquid chromatographic (GLC) method has been developed for the determination of captan (N-trichloromethylthio-4-cyclohexene-1, 2-dicarboximide) and 2 metabolites, tetrahydrophthalimide (THPI) and tetrahydrophthalamic acid (THPMA), in milk and meat. The sample is extracted with ethyl acetate and is cleaned up by acetonitrile partition and silica gel chromatography where captan, THPI, and THPMA are separated. Captan is directly determined by GLC. THPI and THPMA are separately derivatized in an acetone solution of penta fluorobenzyl bromide. The resultant derivatives are purified separately on an Al2O3, column and quantitated by GLC, using an electron capture detector. Recoveries from milk samples fortified at 0.02–10 ppm ranged from 71 to 102%; recoveries from meat samples fortified at 0.04–10 ppm ranged from 75 to 99%.

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