Evaluation of dried blood spots as an alternative sample matrix for equine antidoping analysis

Advances in SARMs anti-doping analysis

Selective androgen receptor modulators (SARMs) are performance-enhancing drugs (PEDs) that stimulate anabolism, increase muscle mass and strength and promote recovery from exercise. The use of SARMs in sports is considered doping and is strictly prohibited by the World Anti-Doping Agency (WADA) and the International Federation of Horseracing Authorities (IFHA). To monitor the abuse of SARMs in sports, it is essential to develop advanced, selective and sensitive analytical methods that provide reliable results. This review evaluates the advances in this area, with a focus on the identification of target analytes related to SARMs, such as SARMs, their metabolites or markers. The aim is to identify targets that could extend the detection windows of SARMs, provide scientific support for results management and/or offer an indirect biomarker-based approach to doping control. This review also aims to evaluate the current liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) methods developed for the monitoring of SARMs in different biological matrices, including traditional matrices such as urine and serum/plasma samples, as well as alternative matrices such as dried blood spots, hair and nail samples.

Dried Blood Spots technology for veterinary applications and biological investigations: technical aspects, retrospective analysis, ongoing status and future perspectives

Dried Blood Spots (DBS) technology has become a valuable tool in medical studies, however, in veterinary and biological research DBS technology applications are still limited. Up-to-date no review has comprehensively integrated all the evidence existing across the fields, technologies and animal species. In this paper we summarize the current applications of DBS technology in the mentioned areas, and provide a scope of different types of dried sample carriers (cellulose and non-cellulose), sampling devices, applicable methods for analyte extraction and detection. Mammals, birds, insects and other species are represented as the study objects. Besides the blood, the review considers a variety of specimens, such as milk, saliva, tissue samples and others. The main applications of dried samples highlighted in the review include epidemiological surveys and monitoring for infections agents or specific antibodies for disease/vaccination control in households and wildlife. Besides the genetic investigations, the paper describes detection of environmental contaminants, pregnancy diagnosis and many other useful applications of animal dried samples. The paper also analyses dried sample stability and storage conditions for antibodies, viruses and other substances. Finally, recent developments and future research for DBS technology in veterinary medicine and biological sciences are discussed.

Detection and Confirmation of Zilpaterol in Equine Hair Using Liquid Chromatography - Mass Spectrometry

Zilpaterol is a β₂ -adrenergic agonist and a repartitioning agent that has a high potential for abuse in equine performance athletes. Analysis of zilpaterol in hair is an alternative sampling matrix that extends detection time periods beyond those found in urine or blood samples. Our laboratory has been screening for zilpaterol in hair for many years and recently detected and confirmed its presence in official samples. Accordingly, a liquid chromatography - mass spectrometry method was developed and validated to detect and confirm zilpaterol in equine hair. Briefly, equine hair was decontaminated, cut, and pulverized prior to disruption and liquid-liquid extraction in basic conditions. Following extraction, the sample was introduced to an Agilent 1260 HPLC and zilpaterol was separated using a reverse phase gradient with a total run time of 12.5 minutes. Following chromatographic separation, zilpaterol and its corresponding stable isotope labeled internal standard were introduced via positive mode electrospray ionization to a Thermo Q-Exactive Plus mass spectrometer and spectra collected using parallel reaction monitoring. The methodology was validated using in-house criteria including characterization of accuracy, precision, recovery, linear range, matrix effects, limit of detection and limit of quantitation and the method was found to be fit-for-purpose to confirm the presence of zilpaterol in equine hair. This methodology has been used to detect and confirm the presence of zilpaterol from out-of-competition hair samples submitted by regional racing authorities.

Dried blood spots in doping analysis

A series of dried blood spot (DBS) detection methods for doping agents have been developed in the last two decades. The DBS technique minimizes invasiveness and reduces storage and shipping costs. Recently, the World Anti-Doping Agency announced the use of DBS for the 2022 Beijing Winter Olympic Games and Paralympic Games owing to the advantages of the DBS application in routine doping control. Therefore the further development of detection methods for doping agents in DBS is important and urgent. This review summarizes five aspects of DBS application in doping analysis: sample collection, storage conditions, pretreatment, instrumentation and validation according to the Prohibited List issued by the World Anti-Doping Agency, and proposes some suggestions for future studies of DBS in doping analysis.