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

Supramolecular solvents: a gateway to all-in-one extractions in chemical exposomics

The characterization of the human chemical exposome through daily estimated intakes or biomonitoring has become paramount to understand the causal pathways leading to common diseases. The paradigm shift that has taken place in looking at health has moved research from the classical biomedical model based on "one exposure, one disease" to a more comprehensive approach based on multiple chemicals and low dose effects. For this purpose, untargeted and/or suspect analysis of chemicals based on liquid chromatography and high-resolution mass spectrometry (LC-HRMS) has been proposed as the most relevant strategy for sequencing the exposome. A key aspect in this respect is the development of unbiased sample preparation methods that efficiently concentrate the wide range of untargeted/suspected chemicals while minimizing interference from sample matrices. Here, we aim to critically discuss the potential of tailored supramolecular solvents (SUPRAS) for achieving all-in-one extractions in chemical exposomics, as an alternative to overcome the limitations of the current sample treatment strategies, on the basis of their intrinsic properties and the applications reported so far.

Development of a supramolecular solvent-based extraction method for application to quantitative analyses of a wide range of organic contaminants in indoor dust

This study investigates the efficacy of supramolecular solvent (SUPRAS) in extracting a diverse spectrum of organic contaminants from indoor dust. Initially, seven distinct SUPRAS were assessed across nine categories of contaminants to identify the most effective one. A SUPRAS comprising Milli-Q water, tetrahydrofuran, and hexanol in a 70:20:10 ratio, respectively, demonstrated the best extraction performance and was employed for testing a wider array of organic contaminants. Furthermore, we applied the selected SUPRAS for the extraction of organic compounds from the NIST Standard Reference Material (SRM) 2585. In parallel, we performed the extraction of NIST SRM 2585 with conventional extraction methods using hexane:acetone (1:1) for non-polar contaminants and methanol (100%) extraction for polar contaminants. Analysis from two independent laboratories (in Norway and the Czech Republic) demonstrated the viability of SUPRAS for the simultaneous extraction of twelve groups of organic contaminants with a broad range of physico-chemical properties including plastic additives, pesticides, and combustion by-products. However, caution is advised when employing SUPRAS for highly polar contaminants like current-use pesticides or volatile substances like naphthalene.

Tailoring supramolecular solvents with phosphoryl groups for highly efficient extraction of chlorophenols in natural waters

BACKGROUND

Chlorophenols are routinely determined in aquatic systems to check compliance with the restrictive international legislations set for protection of human and aquatic life. Their control requires affordable analytical methods, particularly in labs at low- and medium-income countries. Liquid chromatography-UV detection is a convenient technique for this purpose, but the availability of suitable sample processing remains pending. Organic solvents are inefficient for extracting the whole range of chlorophenols whereas solid-phase extractions are expensive and labour-intensive. So, an efficient, fast and cheap extraction of chlorophenols, amenable to any lab, would help to cope with their worldwide analytical control in natural waters.

RESULTS

A supramolecular solvent (SUPRAS) was tailored for providing mixed interaction mechanisms aimed at the efficient extraction of chlorophenols prior to LC-UV. The SUPRAS was synthesized from the self-assembly of hexylphosphonic acid under acidic conditions and consisted of sponge-like nanostructures made up of amphiphile and water. The phosphoryl (PO) group was selected as the major driver of the extraction because of its ability to act as halogen and hydrogen bond acceptor for chlorophenols. Additional interactions were hydrogen bonds from O-H amphiphilic groups and the surrounding water, and dispersion and CH-π interactions in the hydrocarbon chains. The number of binding sites in the SUPRAS could be modulated by addition of salt. The SUPRAS formed in situ in the sample, the extraction took 5 min, the concentration factor was around 220, quantification limits (0.1-0.3 μg L-1) were below the EU standards, and the method worked for natural waters.

SIGNIFICANCE

A fast, low-cost, and organic solvent-free sample processing only requiring conventional lab equipment (stirrers and centrifuges) provided SUPRAS extracts that could be directly analyzed by LC-UV. SUPRAS synthesis occurred spontaneously in the water sample under addition of hexylphosphonic acid and the whole process required low skills. The method meets the analytical and operational performances for the analytical control of chlorophenols in natural waters and it is within the reach of any lab.

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.

Annual banned-substance review-Analytical approaches in human sports drug testing 2021/2022

Also in 2021/2022, considerable efforts were invested into advancing human sports drug testing programs, recognizing and taking into account existing as well as emerging challenges in anti-doping, especially with regard to substances and methods of doping specified in the World Anti-Doping Agency's 2022 Prohibited List. In this edition of the annual banned-substance review, literature on recent developments published between October 2021 and September 2022 is summarized and discussed. Focus is put particularly on enhanced analytical approaches and complementary testing options in human doping controls, appreciating the exigence and mission in anti-doping and, equally, the contemporary "new normal" considering, for example, the athlete's exposome versus analytical sensitivity and applicable anti-doping regulations for result interpretation and management.

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.