Supramolecular solvents for making comprehensive liquid-liquid microextraction in multiclass screening methods for drugs of abuse in urine based on liquid chromatography-high resolution mass spectrometry.

Multiclass screening methods involving hundreds of structurally unrelated compounds are becoming essential in many control labs and research areas. Accurate mass screening of a theoretically unlimited number of chemicals can be undertaken using liquid chromatography coupled to high resolution mass spectrometry (LCHRMS), but the lack of comprehensive sample treatments hinders this unlimited potential. In this research, the capability of supramolecular solvents (SUPRAS) for making comprehensive liquid-liquid microextraction (LLME) in multiclass screening methods based on LCHRMS was firstly explored. For this purpose, a SUPRAS made up of 1,2-hexanediol, sodium sulphate and water was synthesized directly in the urine and applied to compound extraction and interference removal in the screening of eighty prohibited substances in sports by LC-electrospray ionization-time of flight mass spectrometry. Selected substances included a wide range of polarities (log P from -2.4 to 9.2) and functionalities (e.g. alcohol, amine, amide, carboxyl, ether, ester, ketone, sulfonyl, etc.). No interfering peaks were observed for any of the 80 substances investigated. Around 84-93% of drugs were efficiently extracted (recoveries 70-120%) and 83-94% of the analytes did not show matrix effects (±20%) in the ten tested urines. Method detection limits for the drugs were in the interval 0.002-12.9 ng mL-1, which are in accordance with the Minimum Required Performance Levels values established by the World Anti-Doping Agency. The applicability of the method was evaluated by the screening of thirty-six blinded and anonymized urine samples, previously analyzed by gas or liquid chromatography-triple quadrupole. Seven of the samples lead to an adverse analytical finding in line with the results obtained by the conventional methods. This research proves that LLME based on SUPRAS constitutes an efficient, economic, and simple sample treatment in multiclass screening methods, an application that is unaffordable for conventional organic solvents.

Green nanostructured liquids for the analysis of urine in drug-facilitated sexual assault cases.

In this work, we optimize and validate a simple, time-saving, and environmentally friendly sample preparation method based on supramolecular solvents (SUPRAS), green nanostructured liquids, for the extraction of selected drug-facilitated sexual assault (DFSA) substances from human urine. The methodology was fast and simple (stirring, centrifugation, and dilution). Cubosomic SUPRAS were formed by the addition of 1,2-hexanediol (200 µL) to 1.0 mL of human urine containing 1 M Na2SO4. SUPRAS extracts were analyzed by LC-MS/MS. The method was fully validated for 23 DFSA compounds including 10 benzodiazepines, 1 z-hypnotic drug, 5 amphetamine derivatives, 3 cocaine metabolites, and 4 miscellaneous compounds. Extraction efficiency varied between 79 and 119%, and matrix effects were acceptable (-14.3/+21.5) for 87% of the compounds. Method detection and quantification limits ranged from 0.003 to 0.75 ng/mL and from 0.01 to 2.50 ng/mL, respectively. These values were low enough for the established minimum required performance limits (MRPL) of these substances. This simple and green method has a great potential to be implemented for the monitoring of illegal drugs involved in DFSA cases by forensic laboratories.

Cubosomic Supramolecular Solvents: Synthesis, Characterization, and Potential for High-Throughput Multiclass Testing of Banned Substances in Urine.

This paper was intended to efficiently extract multiclass prohibited substances in human sport drug testing by using supramolecular solvents (SUPRASs) made up of cubosomes. These SUPRASs, here first reported, are synthesized by the salt-induced coacervation of 1,2-hexanediol in urine. The formation of square and rounded cubosomes with a size range of 140-240 nm was confirmed by electron microscopy. These nanostructures consisted of 1,2-hexanediol, salt, and a high water content (36-61%, w/w). Their applicability in multiclass determinations was investigated by the extraction of 92 prohibited substances (log P from 2.4 to 9.2) belonging to the 10 categories of the World Anti-Doping Agency's (WADA) list. Variables influencing both recoveries and matrix effects were optimized. Cubosomic SUPRASs showed high extraction efficiency and interference removal capability, which was attributed to their large hydrophilicity and surface area. Both features were superior to those of the other 11 SUPRASs that were based on sponge droplets and inverted hexagonal aggregates and to those of conventional organic solvents. A sport drug-testing method based on cubosomic SUPRAS-LC-ESI-MS/MS was proposed and validated. Around 82-95% of drugs were efficiently extracted (recoveries 70-120%) in urine samples, and 81-92% did not present matrix effects. The method detection limits (0.001-4.2 ng mL-1) were all far below WADA's limits. The proposed SUPRAS-based sample treatment is as simple as QuEChERS, but the distinctive features of cubosomes confer them high capability in multiclass determinations.

A comprehensive study on the performance of different retention mechanisms in sport drug testing by liquid chromatography tandem mass spectrometry.

Anti-doping substances listed by the World Anti-Doping Agency (WADA) include hundreds of compounds of very different physico-chemical properties. Anti-doping control laboratories need to screen all these substances in the so-called Initial Testing Procedures (ITPs) what is very challenging from an analytical point of view. ITPs are mostly based on reversed-phase (RP) liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) using C18 columns, which feature poor retention and peak tailing for polar and basic compounds, respectively. While studies on this field dealing with the comparison of stationary phases are focused on certain chemical classes, this research provides a wide multi-target approach. For this purpose, a representative group of 93 anti-doping agents (log P from -2.4 to 9.2) included in ten different classes of prohibited substances was selected. A comprehensive study on the performance of six columns and four eluents on different separation parameters (retention factors, asymmetry factors, co-elutions, total run times) and matrix effects (signal enhancement or suppression) was performed for LC-MS/MS-based ITPs. Columns working in both RP [C18, C8, phenyl hexyl (PH), pentafluorophenyl (PFP) and mixed-mode hydrophilic/RP (HILIC-RP)) and hydrophilic (HILIC)] modes were investigated. Eluents contained methanol or acetonitrile as organic modifiers, with or without the addition of ammonium acetate. The best column-mobile phase binomial for ITPs was PFP using water-methanol (0.1% formic acid) as eluent, while HILIC was the best option for highly polar non-aromatic anti-doping agents, which were poorly addressed by PFP. Excellent good peak shapes and relative acceptable matrix interferences were obtained for HILIC-RP, which was tested for the first time for the analysis of anti-doping agents, although the number of compounds eluting too fast was too high. On the whole, the alkyl phase C18 showed the worst performance and although C8 and PH were better, their performance did not surpass that of PFP. Possible retention mechanisms underlying separation in the different stationary phases were discussed. This research provides valuable information to anti-doping control labs for improving LC-MS/MS-based ITPs and it proposes PFP as a suitable alternative to the already established C18.

A review on contaminants of emerging concern in European raptors (2002-2020).

Raptors (birds of prey and owls) have been widely used as suitable bioindicators of environmental pollution. They occupy the highest trophic positions in their food chains and are documented to bioaccumulate high concentrations of persistent pollutants such as toxic metals and legacy persistent organic pollutants (POPs).Whereas raptors played a critical role in developing awareness of and policy for chemical pollution, they have thus far played a much smaller role in current research on contaminants of emerging concern (CECs). Given the critical knowledge obtained from monitoring 'legacy contaminants' in raptors, more information on the levels and effects of CECs on raptors is urgently needed. This study critically reviews studies on raptors from Europe reporting the occurrence of CECs with focus on the investigated species, the sampled matrices, and the bioanalytical methods applied. Based on this, we aimed to identify future needs for monitoring CECs in Europe. Perfluoroalkyl substances (PFASs), novel flame retardants (NFRs), and to a lesser extent UV-filters, neonicotinoids, chlorinated paraffins, parabens and bisphenols have been reported in European raptors. White-tailed Eagle (Haliaeetus albicilla), Peregrine falcon (Falco peregrinus) and Northern goshawk (Accipiter gentilis) were the most frequently studied raptor species. Among matrices, eggs, feathers and plasma were the most widely employed, although the potential role of the preen gland as an excretory organ for CECs has recently been proposed. This review highlights the following research priorities for pollution research on raptors in Europe: 1) studies covering all the main classes of CECs; 2) research in other European regions (mainly East Europe); 3) identification of the most suitable matrices and species for the analysis of different CECs; and 4) the application of alternative sample treatment strategies (e.g. QuEChERS or pressurized liquid extraction) is still limited and conventional solvent-extraction is the preferred choice.

Bioaccumulation potential of bisphenols and benzophenone UV filters: A multiresidue approach in raptor tissues.

Environmental exposure to bisphenols and benzophenone UV filters has received considerable attention due to the ubiquitous occurrence of these contaminants in the environment and their potential adverse health effects. The occurrence of bisphenols and benzophenone UV filters is well established in human populations, but data is scarce for wildlife, and especially for raptors (birds of prey, falcons and owls). In this study, concentrations of eight bisphenols and five benzophenone UV filters were determined in six raptor tissues, including muscle, kidney, liver, brain, preen gland (uropygial gland) and adipose. The tissue samples (n = 44) were taken from dead raptor species (1997-2011), including Eurasian sparrowhawks (Accipiter nisus, n = 2) and long-eared owls (Asio otus, n = 2), both from France, and white-tailed eagles (Haliaeetus albicilla, n = 16) from Greenland. Overall, six bisphenols and four benzophenone UV filters were found in the samples. Bisphenol A (BPA), bisphenol F (BPF), benzophenone-8 (BzP-8) and 4-hydroxybenzophenone (4-OH-BzP) were the most abundant contaminants, accounting for median concentrations of 67.5, 3.01, 27.1 and 9.70 ng/g wet weight (w.w.), respectively. The potential role of the preen gland as a major excretory organ for bisphenols and benzophenone UV filters was suggested since the median sum concentration of the two contaminant classes in the white-tailed eagle tissues showed higher bioaccumulation potential in the preen gland (5.86 ng/g w.w.) than the liver (2.92) and kidney (0.71). The concentrations of these contaminants in the tissues of the three raptor species indicated a pattern of increasing detection rates and median concentrations with an increase of the species size and their expected trophic position. To the best of our knowledge, this is the first peer-reviewed study to document multiresidues of both contaminant classes in raptor tissues.

A high thermally stable oligomer-based supramolecular solvent for universal headspace Gas Chromatography: Proof-of-principle determination of residual solvents in drugs.

Supramolecular solvent (SUPRAS) extraction is gaining attraction as a sample treatment technique because of its great performance in terms of effectiveness, versatility, sample clean-up, quickness, cost and sustainability. However, the nature of SUPRASs, being formed by amphiphile molecules, results in poor compatibility with Gas Chromatography (GC). Here, we show the hitherto unexplored development of a SUPRAS with high thermal stability (HTS) suitable for subsequent direct analysis by Headspace (HS)-GC. This novel HTS-SUPRAS, based on poly-undecylenic acid -an oligomeric surfactant-, tetraglyme -a polar aprotic solvent with excellent chemical and thermal stability- and water, was fully characterized in terms of composition and physical properties such as thermal stability. Subsequently, the HTS-SUPRAS developed was further successfully applied, as a proof-of-principle, to the extraction and determination of residual solvents in pharmaceutical drugs, including several solvents (class 2C) whose analysis by HS-GC has been shown to be highly complex. Analytical performance was demonstrated as mandated by the International Council for Harmonisation of technical requirements for pharmaceuticals for human use (ICH). Furthermore, excellent recoveries (70-120%) and high precisions (<20%, expressed as relative standard deviations) were obtained for the analysis of several different drug formulations spiked with the analyzed 37 residual solvents at their respective maximum residue levels.