External contamination of bovine hair with beta2-agonist compounds: evaluation of decontamination strategies

Sensitive detection of clenbuterol by hybrid iridium/silicon nanowire-enhanced laser desorption/ionization mass spectrometry

There is increasing demand for anti-doping drug monitoring in sports and food safety checks by developing sensitive and fast analytical methods. Here we report the development of hybrid Ir/SiNW as a new MALDI matrix for the detection of small molecules. This matrix is characterized by sufficient UV absorption, low-noise background, and high efficiency in ionization of small molecules. Sensitive detection of clenbuterol (LOD: 0.18 pmol) and a variety of other small molecules has been achieved using the Ir/SiNW matrix with a reproducible performance. Compared to the individual components separately, the matrix of hybrid Ir/SiNW synthesized via in situ growth can promote the MS signal intensity by up to 10 fold under identical experimental conditions. We provide a unique mechanism for the high performance of the hybrid Ir/SiNW matrix with the characteristic properties of hydrogen atom transfer and enhanced protonation at the interface of the hybrid nanostructures. Our approach of using a hybrid Ir/SiNW matrix enables detection of clenbuterol quantitatively in complicated biological samples and in vivo experiments, promising a useful tool for food security and anti-doping drug monitoring in sports.

Ultratrace LC-MS/MS analysis of segmented calf hair for retrospective assessment of time of clenbuterol administration in Agriforensics

In agriforensics, time of administration is often debated when illegal drug residues, such as clenbuterol, are found in frequently traded cattle. In this proof-of-concept work, the feasibility of obtaining retrospective timeline information from segmented calf tail hair analyses has been studied. First, an ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) hair analysis method was adapted to accommodate smaller sample sizes and in-house validated. Then, longitudinal 1 cm segments of calf tail hair were analyzed to obtain clenbuterol concentration profiles. The profiles found were in good agreement with calculated, theoretical positions of the clenbuterol residues along the hair. Following assessment of the average growth rate of calf tail hair, time of clenbuterol administration could be retrospectively determined from segmented hair analysis data. The data from the initial animal treatment study (n = 2) suggest that time of treatment can be retrospectively estimated with an error of 3-17 days.

Development, validation and application to real samples of a multiresidue LC-MS/MS method for determination of β2 -agonists and anabolic steroids in bovine hair

β(2) -agonists are often abused in cattle breeding because of their effects on animal growth and meat properties. The use of β(2) -agonists as growth promoters is forbidden in the European Union (Council Directive 96/23/EC classifies them into group A of Annex I), due to their toxicity and carcinogenic properties, as for anabolic steroids, which are often administered in combination with β(2) -agonists, to promote the storage of proteins and increase muscle size. A unique confirmatory liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantitative detection of 13 β(2) -agonists and anabolic steroids plus the qualitative identification of other three analytes in bovine hair was developed and validated, according to Decision 2002/657/CE. Hair samples were washed with dichloromethane, digested within a NaOH solution and subjected to liquid-liquid extraction. The analysis was performed by high performance liquid chromatography coupled to a triple quadrupole mass spectrometer operating in the selected reaction monitoring mode. The absence of matrix interferents, together with good repeatability of both retention times and relative abundances of diagnostic transitions, allowed the correct identification of all analytes. The quantitative calibrations obtained from spiked blank hair samples proved linear in the range tested. CCα and CCβ ranged from 0.5 ng/g to 30 ng/g. Intralaboratory reproducibility (CV%) ranged between 5.0 and 17.7 and trueness between 96% ± 7% and 105% ± 8%. The applicability of the method to real positive samples was demonstrated for both β(2) -agonists and anabolic steroids. 17α-boldenone was found in most (70%) hair samples obtained from untreated animals, supporting the hypothesis of endogenous production of this steroid.

Analytical methods for the detection of clenbuterol

Clenbuterol is therapeutically used for the treatment of pulmonary diseases such as bronchial asthma or for tocolytic reasons. In cattle feeding as well as in sports it is illicitly misused due to its anabolic properties to promote muscle growth. Sample preparation procedures and analytical techniques used for the detection of clenbuterol are manifold and vary with the objectives of the investigation. Methods for its detection in biological specimens, drug preparations, the environment, food and feed products are reported. They are mainly based on immunochemical, chromatographic and mass spectrometric techniques, or on capillary electrophoresis. Sample preparation primarily includes liquid-liquid extraction and solid-phase extraction. Depending on the aim of the method clenbuterol can be determined in single- or multi-analyte methods. In biological and environmental samples concentrations are generally low due to the potency of the drug. Thus, highly sensitive procedures are required for expedient analyses.

Hair analysis for veterinary drug monitoring in livestock production

This review summarizes the basic information and applications concerning the use of hair analysis for the detection of misuse of therapeutic and anabolic agents in livestock animals. Hair biology, hair-shaft structure and the mechanisms of drug incorporation are described, considering the different factors which can affect the deposition. Sampling and extraction methods are reviewed with special attention to the particularities of this matrix, while the use of different analytical techniques is discussed, taking into account the concentration and the sensitivity required for drug detection. Advantages, drawbacks, promising prospects and possible applications of this technique in the future are also discussed.

Detection of sulphamethazine residues in cattle and pig hair by HPLC–DAD

An HPLC method with diode array detection (DAD) is proposed for the detection of sulphamethazine (SMZ) residues in pig and cattle hair. Hair samples were extracted under alkaline conditions (NH4OH 0.2M for calf samples and NaOH 0.1M for piglet samples) and purified with a dual solid-phase extraction (SPE) cartridge system (reverse phase/strong-cation exchange). Recovery of SMZ in fortified samples varied from 70 to 85%, with a limit of quantification of 0.155 ng/mg. Residues of SMZ (7.2-59.2 ng/mg) were detected both in calf and piglet hairs after a therapeutic treatment with SMZ, while no interfering peak was observed in samples from untreated animals.