In addition to the naturally existing HCT fluctuation in a standard population, these fluctuations in an athlete population are more pronounced. Therefore, additional efforts for anti-doping testing may be required to ensure reliable and quantitative DBS analysis that hold their position in court. A consequent HCT strategy for dried blood should be implemented, as the measurement of HCT in dried blood is not as straightforward as in liquid blood. Solutions for HCT measurement from DBS are available and ready to be implemented. The preferred strategy for HCT assessment should be post-sampling and non-destructive, as it keeps the DBS sampling process as simple as possible. Depending on the DBS sampling device in action, the indirect HCT assessment from the dried matrix can be easier or more difficult to implement. Strategies to rapidly measure the HCT from DBS cards non-destructively have been demonstrated in the past. Up to date, no such application has been introduced for the non-card-based microsampling devices.

https://onlinelibrary.wiley.com/doi/abs/10.1002/dta.2977

The World Anti-Doping Agency (WADA) and the International Testing Agency (ITA) recently announced the development and implementation of dried blood spot (DBS) testing for routine analysis in time for the 2022 Winter Olympic and Paralympic Games in Beijing. Following the introduction of a ban on the use of tramadol in competition in March 2019, the Union Cycliste International (UCI) started a pilot study for the manual analysis of tramadol in DBS for antidoping purposes. In this context, we present a fully automated LC–MS/MS-based method with automated sample preparation using a CAMAG DBS-MS 500 for the analysis of tramadol and its metabolite O-desmethyltramadol in DBS. The presented approach reduces manual handling in the laboratory to an absolute minimum, only requiring the preparation of calibration and quality control DBS cards. The method was developed, optimized, and validated before performing cross-validation with a liquid blood-based analysis method using authentic samples from forensic cases. During the validation process, the method showed an extraction efficiency of 62%, linearity r² > 0.99, accuracy and precision (within ± 15% and ± 20% at the LLOQ) for the determination of tramadol and O-desmethyltramadol. Method comparison in liquid blood with 26 samples showed good agreement (90 ± 19% for tramadol and 94 ± 14% for O-desmethyltramadol). In conclusion, automated analysis of tramadol and O-desmethyltramadol in DBS provides a fast and accurate solution for antidoping screening. It is suited for highthroughput analysis, having a run time of about 4 min per sample. Furthermore, with the automated approach, manual sample extraction becomes obsolete.

https://onlinelibrary.wiley.com/doi/abs/10.1002/dta.2819

In the past decade, dried blood spot (DBS) sampling has been used increasingly for microsampling in various fields. This is predominantly driven by the significant advantages DBS offers regarding simple sample retrieval and shipment, combined with increased analyte stability. However, the manual handling of DBS samples is laborsome and prevents the use of a high-capacity bioanalytical workflow. The recent introduction of robotic DBS extraction systems in combination with liquid chromatography-tandem mass spectrometry (LC-MS/MS) has enabled the full automation of the analytical process. This results in overall higher sample throughput, minimal user interaction, and a significant reduction in consumables. Different instrumental setups are currently available which differ with respect to the extraction process, extract processing strategy, and internal standard application. This review article provides an overview of fully automated DBS analysis for one of these instruments, the DBS-MS 500 autosampler from CAMAG. The automated processes are described in detail and various applications are presented. Emphasis is placed on the advantages that the use of DBS, in combination with automation, brings – such as speed, reliability, and userfriendliness. Discussing DBS solutions for newborn screening, workplace drug testing, forensic screening, direct alcohol marker analysis, antiretroviral drugs, anti-epileptic drugs, and mass drug administration, the versatility and applicability of DBS are demonstrated in detail. In conclusion, this article shows how and why fully automated DBS analysis has penetrated the routine laboratory environment.

https://www.sciencedirect.com/science/article/pii/S0009912019313682?via%3Dihub

At the beginning of 2020, an outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reached pandemic dimensions. Throughout the event, diagnostic tests function as an essential tool for understanding, mitigating, and implement strategies to curb and reduce infections. Here, we present a novel method for the fully automated dried blood spot (DBS) sample handling and extraction for serological testing of human IgG antibodies against SARS-CoV-2 using a commercial enzymelinked immunosorbent assay (ELISA) testing kit. This proof-of-principle pilot study successfully demonstrates the recovery of antibodies in their intact form from DBS using automated, direct sample elution within 100 μl of extraction buffer. The use of minimally invasive DBS sampling provides an alternative to existing analytical procedures such as sampling by venipuncture or nasal swabs. Due to the ease of DBS collection, no third party need be involved, making at-home sampling possible (e.g., during quarantine).

https://onlinelibrary.wiley.com/doi/10.1002/dta.2946

Phosphatidylethanol (PEth) in human blood samples is a marker for alcohol usage. Typically, PEth is detected by reversed-phase liquid chromatography coupled with negative ion tandem mass spectrometry, investigating the fatty acyl anions released from the precursor ion upon collision-induced dissociation (CID). It has been established that in other classes of asymmetric glycerophospholipids the unimolecular fragmentation upon CID is biased depending on the relative position (known as sn-position) of each fatty acyl chain on the glycerol backbone. As such, the use of product ions in selected-reaction-monitoring (SRM) transitions could be prone to variability if more than one regioisomer is present in either the reference materials or the sample. Here, we have investigated the regioisomeric purity of three reference materials supplied by different vendors, labelled as PEth 16:0/18:1. Using CID coupled with ozoneinduced dissociation, the regioisomeric purity (% 16:0 at sn-1) was determined to be 76%, 80% and 99%. The parallel investigation of the negative ion CID mass spectra of standards revealed differences in product ion ratios for both fatty acyl chain product ions and ketene neutral loss product ions. Furthermore, investigation of the product ion abundances in CID spectra of PEth within authentic blood samples appears to indicate a limited natural variation in isomer populations between samples, with the cannonical, PEth 16:0/18:1 (16:0 at sn-1) predominant in all cases. Different reference material isomer distributions led to variation in fully automated quantification of PEth in 56 authentic dried blood spot (DBS) samples when a single quantifier ion was used. Our results suggest caution in ensuring the regioisomeric composition of reference materials are well-matched with the authentic blood samples.

https://academic.oup.com/jat/advance-article-abstract/doi/10.1093/jat/bkaa034/5815966

In this study, we describe the transfer of a new and fully automated workflow for the cost-effective drug screening of large populations based on the dried blood spot (DBS) technology. The method was installed at a routine poison control center and applied for DBS and dried urine spot (DUS) samples. A fast method focusing on the high-interest drugs and an extended screening method were developed on the automated platform. The dried cards were integrated into the automated workflow, in which the cards were checked in a camera recognition system, spiked with deuterated standards via an in-built spraying module and directly extracted. The extract was transferred online to an analytical LC column and then to the electrospray ionization tandem mass spectrometry system. The target compounds were analyzed in positive multiple-reaction monitoring mode. Before each sample batch or analysis day, calibration samples were measured to balance inter-day variations and to avoid false negative samples. An internal standard was integrated prior the sample extraction to allow in process control. A total of 28 target compounds were analyzed and directly extracted within 5 min per sample. This fast screening method was then extended to 20 min, enabling the usage of a Forensic Toxicology Database to screen over 1,200 drugs. The method gives confident positive/negative results for all tested drugs at their individual cut-off concentration. Good precision (±15%, respectively ±20% at limit of quantification) and correlation within the calibration range from 5 to 1,000 ng/mL was obtained. The method was finally applied to real cases from the lab and cross-checked with the existing methodologies.

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