Simultaneous Determination of Residues of Chloramphenicol, Florfenicol, Florfenicol Amine, and Thiamphenicol in Shrimp Tissue by Gas Chromatography with Electron Capture Detection

Abstract

A gas chromatographic (GC) method is presented for determining residues of chloramphenicol (CAP), florfenicol (FF), florfenicol amine (FFa), and thiamphenicol (TAP) in shrimp tissues, with meta-nitrochloramphenicol (mCAP) as the internal standard. The composited shrimp is extracted with basic ethyl acetate, followed by an acetonitrile–basic ethyl acetate mixture. This extract is centrifuged, filtered, evaporated, and reconstituted in water; the reconstituted extract is acidified, defatted with hexane, and passed through a propylsulfonic acid (PRS) and C18 solid-phase extraction (SPE) system. The C18 SPE column is eluted with methanol, and the PRS SPE column is eluted with basic MeOH plus counter ion. The combined eluates are evaporated, reconstituted in acetonitrile, and derivatized with Sylon BFT. After derivatization, the addition of toluene directly to the sample, followed by the addition of basic water, quenches the derivatization process. After centrifugation, the organic layer is carefully removed, and the analytes are determined by GC with electron capture detection. Shrimp tissues were fortified with fenicols (i.e., CAP, FF, FFa, and TAP) at 5, 10, 20, 40, and 80 ng/mL. Overall recoveries were 88, 101, 91, and 84% with overall interassay (between-day) variabilities (i.e., relative standard deviations) of 5.3, 9.4, 12.8, and 7.4% for CAP, FF, FFa, and TAP, respectively. The method detection limits were calculated as 0.7, 1.4, 2.4, and 1.3 ng/g (ppb) for CAP, FF, FFa, and TAP, respectively, based on a 10 g sample. The quantitation limit as determined empirically by this method is the lower limit of the standard curve, which is about 5 ng/g (ppb) for each analyte.

Spectrophotometric Determination of Chloramphenicol in Pharmaceutical Preparations

“…The most serious and potentially lethal effect of chloramphenicol is a plastic anemia (4). Several methods have been reported for the determination of CAP including titration (5),spectrophotometry (2,(6)(7)(8)biosensor immunoassay (9), gas chromatography (10,11) , liquid chromatography-mass spectrometry (12),liquid chromatography-electrospray ionisation tandem mass spectrometry (13,14),enzyme-liquid immunosorbent assay (15)(16)(17), molecularly imprinted polymer for HPLC (1), chemiluminescences (18), differential-pulse polagraphy (19) and derivative spectrophotometry (20). Among the various methods available for the determination of the drug, spectrophotometry continues to be very popular, because of its simplicity, specificity and low cost.…”

Depletion of florfenicol in lactating dairy cows after intramammary and subcutaneous administration

“…The HPLC procedure used for screening was not amenable to processing the large numbers of samples that had been collected for pharmacokinetic analyses. Hence, a gas-liquid chromatographic (GC) procedure with electron capture detection based on the method described by Pfenning et al (Pfenning et al, 1998(Pfenning et al, , 2000 was used for all subsequent analyses of the plasma samples and the reanalyses of all the milk samples.…”

Quantification and Analysis of Trace Levels of Phenicols in Feed by Liquid Chromatography–Mass Spectrometry

“…Sample preparation is critical to the validity of trace analysis. Previous investigations have set forth various types of pretreatment methods for fenicols in food before chromatographic determination, including liquid-liquid extraction (LLE) [28], solid-phase extraction (SPE) [29] or QuEChERS technique [27]. Conventional methods for extraction of organic analytes from food samples usually consist of a homogenisation step, followed by tedious liquid-liquid extraction procedures with one or more several clean-up steps and purification of the extract to remove co-extractants, before the sample is subjected to chromatographic separation.…”