Rapid and simple determination of clenbuterol residues in retina by high-performance liquid chromatography with ultraviolet detection

Magnetic separation of clenbuterol based on competitive immunoassay and evaluation by surface-enhanced Raman spectroscopy

The elimination of β-agonist has attracted considerable interest due to its harmfulness to human health when it existed in pork.

Multiresidue Determination of β2-Agonists Including Phenylethanolamine A in Animal-Derived Food by Ultra-High Performance Liquid Chromatography/Tandem Mass Spectrometry

A comprehensive ultra-high performance liquid chromatography/tandem mass spectrometry (UHPLC/MS/MS) procedure for detection of nine β-agonists in animal-derived food is described. The method was based on enzymatic hydrolysis with β-glucuronidase from Helix pomatia, followed by a liquid-liquid extraction procedure with perchloric acid and a solid-phase extraction scheme using two kinds of cartridges, HLB and MCX. The influence of sample solution pH in the extraction recovery was studied, and pH 4.0 was found to give the best recovery. The analytes were eluted with methanol containing 4% ammonia. A validation procedure for quantitative analysis of β-agonists in animal-derived food was performed. The three kinds of internal standards, d3-salbutamol, d6-ractopamine and d9-clenpenterol, were applied in the sample preparation and detection of UHPLC/MS/MS. The recoveries from spiked samples ranged between 74.9 and 106.9%. The relative standard deviations of detection were at 0.7-9.6%. The limits of detection and quantification were 0.01-0.05 and 0.03-0.20 µg/kg, respectively. The effect of sample matrix in the detection was discussed in detail.

Control of the illegal use of clenbuterol in bovine production

This study is based on a plan of collecting different matrices (hair, eye, muscle, liver and kidney) in order to define a strategy for the control of the illegal use of clenbuterol in bovine production. Of all matrices utilised, hair is recommended for the analytical control of clenbuterol in living animals, due to its being permanently available and easy to collect. The eye, or rather the retina, is the matrix which gives the most trustworthy result, after the animal slaughter, and the one that best helps in the determination of the illegal use of clenbuterol in a perspective of gradual food safety improvement.

Comparative analytical quantitation of clenbuterol in biological matrices using GC-MS and EIA

A simple and sensitive procedure utilizing GC-MS for the identification and quantitation of clenbuterol in biofluids and tissues is described. This improved method utilizes trimethylboroxine for the derivatization of clenbuterol, requires only 1 mL/g of biological sample, and most importantly does not require an extra cleaning step for urine specimens prior to extraction. Linear quantitative response curves have been generated for derivatized clenbuterol over a concentration range of 5-200 ng/mL. The extraction efficiency at four representative points of the standard curve exceeded 90% in both specimen types (plasma and urine). Linear regression analyses of the standard curve in both specimen types exhibited correlation coefficients ranging from 0.997 to 1.000. The Limit of detection (LOD) and Limit of quantitation (LOQ) values for plasma specimens were determined to be 0.5 and 1.5 ng/mL respectively. For urine specimens, LOD and LOQ values were 0.2 and 0.7 ng/microL respectively. Percentage recoveries ranged from 91 to 95% for urine and 89 to 101% for plasma. Precision and accuracy (within-run and between-run) studies reflected a high level of reliability and reproducibility of the method. In addition to its reliability, sensitivity and simplicity, this modified procedure is more efficient and cost effective, requiring less time, only 1 mL of sample, and minimal amounts of extraction solvents. The applicability of the method for the detection and quantitation of clenbuterol in biological tissues of rats treated with the drug was demonstrated successfully. For comparative analysis of clenbuterol in plasma and liver samples, both GC-MS and enzyme immunoassay (EIA) methods are found to be suitable. Due to potential antibody-cross reactivity with EIA, the GC-MS method is the method of choice for most samples because of its specificity. However, the EIA method is considered the method of choice for analysis of clenbuterol found in concentrations below the limits of quantitation by GC-MS due to its sensitivity.

Quantitative determination of clenbuterol enantiomers in human plasma by high-performance liquid chromatography using the macrocyclic antibiotic chiral stationary phase teicoplanin

We report a method for the high-performance liquid chromatographic (HPLC) chiral separation of racemic clenbuterol in human plasma. Human plasma was spiked with stock solutions of clenbuterol hydrochloride and practolol as the internal standard. Following a liquid-liquid extraction procedure with 10% (+/-)-2-butanol/isopropyl ether under alkaline conditions, the dried samples were reconstituted in methanol and chromatographed using a macrocyclic antibiotic chiral stationary phase (CSP) known as Chirobiotic T(trade mark) (teicoplanin). The mobile phase composition was methanol:acetonitrile (70:30, v/v), containing 0.3% (v/v) acetic acid and 0.2% (v/v) triethylamine. The resulting chromatogram achieved baseline separation for the clenbuterol enantiomers. Calibration curves (peak area ratio vs plasma concentration, n = 10) were constructed for the (-)-R-and (+)-S-clenbuterol enantiomers with a plasma concentration range of 0. 25-10 microM. The correlation coefficient (r) range was 0.99988-0. 99999 (mean = 0.99999). The lowest concentration measured was 0.25 microM. Inter- and intra-assay variation was determined for the lowest, medium and highest plasma concentration (0.25, 2 and 10 microM) by calculating the analytical recoveries with a range of 96-104%. The percentage recoveries for the clenbuterol enantiomers were 88.4-102% over the concentration range used. Detailed methodology is presented.