scholarly journals Multiresidue Analytical Method for the Determination of Eight Penicillin Antibiotics in Muscle Tissue by Ion-Pair Reversed-Phase HPLC after Precolumn Derivatization

1999 ◽  
Vol 82 (5) ◽  
pp. 1083-1095 ◽  
Author(s):  
Eric Verdon ◽  
Pierrick Couëdor

Abstract A high-performance liquid chromatographic multiresidue method was developed for the determination of 8 penicillin compounds (benzylpenicillin, phenoxymethylpenicillin, ampicillin, amoxicillin, nafcillin, oxacillin, cloxacillin, and dicloxacillin) at trace levels in muscle tissue. This method involves extraction of the penicillins with phosphate buffer pH 9 followed by cleanup and concentration on a C18 solid¯phase extraction column and reaction with benzoic anhydride at 50°C for 5 min and with 1,2,4-triazole and mercury(II) chloride solution pH 9 at 65°C for 10 min. The derivatized compounds are eluted on a C18 column with a mobile phase containing acetonitrile and phosphate buffer (pH 6; 0.1 mol/L) loaded with sodium thiosulfate and ion-pairing tetrabutylammonium hydrogenosulphate. The method detection limit is approximately 3-11 μg/kg and the limit of determination was evaluated down to 25 μg/kg in line with the criteria of the EU decision No. 93/256/EEC.

2013 ◽  
Vol 96 (6) ◽  
pp. 1302-1307 ◽  
Author(s):  
Karim Michail ◽  
Hoda Daabees ◽  
Youssef Beltagy ◽  
Magdy Abd Elkhalek ◽  
Mona Khamis

Abstract A validated HPLC-UV method is presented for the quantification of urinary memantine hydrochloride, a novel medication approved to treat moderate and advanced cases of Alzheimer's disease. The drug and amantadine hydrochloride, the internal standard, were extracted from human urine using SPE. The extract was then buffered and derivatized at room temperature using o-phthalaldehyde in the presence of N-acetyl-L-cyteine. Chromatographic separation of the formed derivatives was achieved on a C18 column using methanol–water mobile phase adjusted to pH 7 and pumped isocratically at 1 mL/min. The UV detector was set at 340 nm. The chromatographic run time did not exceed 10 min. The LOD and LOQ were 8 and 20 ng/mL, respectively. The RSDs for intraday and interday precisions did not exceed 5.5%. The method was used to monitor memantine hydrochloride in human urine in order to determine an appropriate sampling interval for future noninvasive therapeutic drug monitoring. The assay could also be applied to the determination of amantadine. The described assay showed that a postdosing time interval of 25–75 h seems adequate for sampling and monitoring memantine in urine.


2008 ◽  
Vol 91 (6) ◽  
pp. 1459-1466 ◽  
Author(s):  
Ji-Ye Hu ◽  
Yu-Chao Zhang ◽  
Hai Yan

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.


1996 ◽  
Vol 79 (3) ◽  
pp. 645-651 ◽  
Author(s):  
Christiaan A J Hajee ◽  
Nel Haagsma

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.


1999 ◽  
Vol 82 (6) ◽  
pp. 1345-1352 ◽  
Author(s):  
Lambert K Sørensen ◽  
Heļga Hansen ◽  
Lena Snor

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).


2009 ◽  
Vol 57 (1) ◽  
pp. 99-107 ◽  
Author(s):  
Diana Žele ◽  
Silvestra Kobal ◽  
Gorazd Vengušt ◽  
Andrej Bidovec ◽  
Anton Vengušt ◽  
...  

A sensitive and reliable method for the determination of trace amounts of abamectin in muscles, kidneys and fat tissue of fallow deer is presented. Abamectin was extracted from the tissues with acetonitrile and the extract was cleaned up on a C8 solid-phase extraction cartridge. Abamectin residue was derivatised with trifluoroacetic acid anhydride and 1-methylimidazole, and determined using reversed- phase high-performance liquid chromatography under isocratic conditions and fluorescence detection. The recoveries of the method were high and consistent, ranging from 78% to 90%. The limit of detection of the method was below 1 μg/kg when analysing muscle, kidney and fat tissue. Matrix-matched calibration was used in order to obtain accurate values and to avoid matrix interference.


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