scholarly journals Determination of Amoxicillin in Trout by Liquid Chromatography with UV Detection after Derivatization

1999 ◽  
Vol 82 (6) ◽  
pp. 1345-1352 ◽  
Author(s):  
Lambert K Sørensen ◽  
Heļga Hansen ◽  
Lena Snor
Keyword(s):  
Solid Phase Extraction ◽  
Muscle Tissue ◽  
Solid Phase ◽  
Reversed Phase ◽  
Uv Detection ◽  
Phase Extraction ◽  
Phase Gradient ◽  
Repeatability Standard Deviation ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method based on solid-phase extraction was developed for determination of amoxicillin in muscle tissue of rainbow trout. The compound was extracted in an aqueous solution by precipitation of organic material with a mixture of sulfuric acid and sodium tungstate. The extract was processed by solid-phase extraction on an end-capped phenyl sorbent, and concentrated on a divinylbenzene-co-ΛN-vinylpyrrolidone polymeric sorbent. The extract was derivatized and analyzed by reversed-phase gradient LC on a C18 column with UV detection at 323 nm. The method detection limit was 2.9 μg/kg. Mean recovery in muscle was 80.5% (range 10-200 μg/kg). The method was applied to fillets from trout offered feed containing amoxicillin in an aquaculture pilot plant. Amoxicillin was detected in muscle tissue shortly after administration but not 3 weeks later. The relative repeatability standard deviation for incurred residues in muscle tissue was 6.4% (range 11-143 μg/kg).

scholarly journals Determination of Flumorph Residues in Vegetables, Soil, and Natural Water by Solid-Phase Extraction Cleanup and High-Performance Liquid Chromatography with UV Detection

2008 ◽  
Vol 91 (6) ◽  
pp. 1459-1466 ◽  
Author(s):  
Ji-Ye Hu ◽  
Yu-Chao Zhang ◽  
Hai Yan
Keyword(s):  
Solid Phase Extraction ◽  
Natural Water ◽  
High Performance ◽  
Solid Phase ◽  
Residue Analysis ◽  
Reversed Phase ◽  
Uv Detection ◽  
Phase Extraction ◽  
Limit Of Quantification

Abstract A method for high-performance liquid chromatographic (HPLC) determination of flumorph residues in cucumber, tomato, soil, and natural water was developed and validated. Primary secondary amine or octadecylsilyl (C18) solid-phase extraction cartridges were used for sample preparation. Reversed-phase HPLC with UV detection was used for separation and quantification of the pesticide. The combined cleanup and chromatographic method steps were sensitive and reliable for simultaneous determination of residues of the 2 isomers of flumorph in the studied samples. This method is characterized by recovery >97.9, coefficient of variation <6.2, and limit of quantification of 0.01 mg/kg, in agreement with directives for method validation in residue analysis. Flumorph residues in the samples were further confirmed by HPLC/mass spectrometry. The proposed method is fast, easy to perform, and could be used for monitoring of pesticide residues.

Determination of Phenol Sulfone, Phenol Sulfoxide, and Phenol Sulfonic Acid Metabolites of Fenamiphos in Soil by Liquid Chromatography

1995 ◽  
Vol 78 (5) ◽  
pp. 1286-1293
Author(s):  
Gregory C Mattern ◽  
Gilbert D Parker ◽  
Debra L Green ◽  
Gregory L Yeutter
Keyword(s):  
Liquid Chromatography ◽  
Solid Phase Extraction ◽  
Sulfonic Acid ◽  
Solid Phase ◽  
Reversed Phase ◽  
Uv Detection ◽  
Phase Extraction ◽  
Soil Matrix ◽  
Phase Liquid

Abstract An analytical method has been developed to quantitate fenamiphos phenol sulfone, phenol sulfoxide, and phenol sulfonic acid in soil. Both control and analyte-fortified soil samples from Fresno, CA, were extracted with methanol–water (2 + 1) and partitioned with ethyl acetate. Fenamiphos phenol sulfone and phenol sulfoxide were determined by re-versed-phase liquid chromatography (LC) with UV detection at 240 nm after cleanup by silica solid-phase extraction. Fenamiphos phenol sulfonic acid was determined by reversed-phase ion-pairing LC with UV detection at 240 nm after cleanup by amino solid-phase extraction. Recoveries of fenamiphos phenol sulfoxide ranged from 88.2 to 111.0%, with an average of 97.4%. Recoveries of fenamiphos phenol sulfone ranged from 101.6 to 107.0%, with an average of 104.6%. Recoveries of fenamiphos phenol sulfonic acid ranged from 76.0 to 99.9%, with an average of 86.0%. Responses for analysis of analytes in both solvent and soil matrix were linear over the tested range of 10 to 500 ppb. Limits of determination of each analyte in soil were less than 10 ppb.

scholarly journals Mixed-Mode Solid-Phase Extraction and Cleanup Procedures for the Liquid Chromatographic Determination of Thiabendazole and Carbendazim in Fruit Juices

2001 ◽  
Vol 84 (2) ◽  
pp. 556-562 ◽  
Author(s):  
Michael S Young ◽  
Dorothy J Phillips ◽  
Pamela C Iraneta ◽  
Jim Krol
Keyword(s):  
Solid Phase Extraction ◽  
Cation Exchange ◽  
Mixed Mode ◽  
Solid Phase ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Phase Extraction ◽  
Grape Juices ◽  
Liquid Chromatographic

Abstract Solid-phase extraction (SPE) procedures were developed for rapid cleanup and determination of thiabendazole and carbendazim in orange, apple, and grape juices. Samples were prepared by using an SPE cartridge containing a mixed-mode sorbent with both reversed-phase and strong cation-exchange chemistries. Analysis was by liquid chromatography with photodiode-array UV detection. Orange juice was analyzed by mixed-mode cation-exchange extraction with reversed-phase cleanup; the other juices were analyzed by reversed-phase extraction with cation-exchange cleanup. Recoveries >80% for carbendazim and >90% for thiabendazole. Quantitation limits were 20 μg/L for both analytes.

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.

Determination of Ticarcillin and Clavulanic Acid in Serum by Liquid Chromatography

1992 ◽  
Vol 75 (1) ◽  
pp. 30-33 ◽  
Author(s):  
Jennifer C Wright ◽  
Carl N Durham ◽  
Jacob R Dunbar
Keyword(s):  
Liquid Chromatography ◽  
Solid Phase Extraction ◽  
Clavulanic Acid ◽  
Solid Phase ◽  
Reversed Phase ◽  
Phase Extraction ◽  
Liquid Chromatographic ◽  
Reversed Phase Lc ◽  
Ml Detection

Abstract A liquid chromatographic (LC) method using solidphase extraction for the determination of clavulanic acid and ticarcillin in human serum has been developed. Clavulanic acid and ticarcillin were extracted separately from 1 mL serum using C18 solid-phase extraction cartridges. Eluates were analyzed by the same reversed-phase LC system. The overall mean recovery of clavulanic acid from serum was 99.7 ±2.3%; the lowest level validated in serum was 0.5 μg/mL. The overall mean recovery of ticarcillin from serum was 101.5 ±3%; the lowest level validated in serum was 12.5 μg/mL. Detection limits for clavulanic acid and ticarcillin were 0.117 and 0.749 μg/mL, respectively.

scholarly journals Determination of Benzoylurea Insecticides in Apples and Pears by Solid-Phase Extraction Cleanup and Liquid Chromatography with UV Detection

1999 ◽  
Vol 82 (1) ◽  
pp. 213-216 ◽  
Author(s):  
Nicholas G Tsiropoulos ◽  
Pipina G Aplada-Sarlis ◽  
George E Miliadis
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Phase Extraction ◽  
Relative Standard ◽  
Benzoylurea Insecticides ◽  
Preliminary Extraction ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method was developed and statistically validated for simultaneous determination of 5 benzoylurea insecticides (di-flubenzuron, triflumuron, teflubenzuron, flufenoxuron, and lufenuron) in apples and pears. It involves preliminary extraction with ethyl acetate–sodium sulfate and cleanup on silica solid-phase extraction cartridges using dichloromethane–2-propanol (9 + 1) as eluant. The eluate is dried under nitrogen and redissolved in methanol. Benzoylurea insecticides are determined by reversed-phase LC with gradient elution at 42°C and UV diode array detection. Recoveries from samples fortified with the 5 insecticides at 0.02–0.5 mg/kg ranged from 83 to 102% for apples and from 75 to 99% for pears. Relative standard deviations were 0–12%. Limits of detection were 0.01 mg/kg for apples and 0.02 mg/kg for pears.

Optimization, Automation, and Validation of the Solid-Phase Extraction Cleanup and On-Line Liquid Chromatographic Determination of N-Methylcarbamate Pesticides in Fruits and Vegetables

1992 ◽  
Vol 75 (6) ◽  
pp. 1063-1072 ◽  
Author(s):  
André De Kok ◽  
Maurice Hiemstra
Keyword(s):  
Solid Phase Extraction ◽  
Fruits And Vegetables ◽  
Solid Phase ◽  
Food Product ◽  
Reversed Phase ◽  
Routine Analysis ◽  
Phase Extraction ◽  
On Line ◽  
Liquid Chromatographic

Abstract A fully automated liquid chromatographic (LC) method was developed for the determination of 21 N-methylcarbamates and 12 of their metabolites. Our previously developed solid-phase extraction (SPE) cleanup method can now be performed using an automated SPE cleanup apparatus. The cleaned-up extract is injected on-line into the LC carbamate analysis system, which is based on a reversed- phase LC separation, postcolumn hydrolysis of the carbamates on a solid-phase catalyst, reaction of the methylamine formed with ophthalaldehyde reagent, and fluorescence detection of the derivatives. The optimized method was evaluated. Recovery and repeatability data were collected for 13 representative carbamates and 12 metabolites on 12 different food product types. The reliability of the method in routine analysis of fruit and vegetable samples is demonstrated. Registration of the analytical results of control samples in Shewhart charts during a year of routine analysis has demonstrated the excellent performance of this complete method. The limits of determination are in the 5-50 μg/kg (ppb) range. Sample throughput is about 20 per 24 h. Data are presented on real residues of N-methylcarbamates found in fruits and vegetables during 4 years of routinely applying this multiresidue method

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