Wide Range Of Polarities Research Articles

HRMS-Targeted-DIA methodology for quantification of wastewater-borne pollutants in surface water

A robust method was developed for the quantification of popular and highly occurrence contaminants of emerging concern from wastewater treatment plant effluents and is explained in detail. A homemade multi-layered and multi-sorbent solid phase extraction (SPE) cartridge was used to cover the wide range of polarities of the selected contaminants. A non-discriminant elution protocol was also applied. Liquid chromatography coupled to a high-resolution mass spectrometer (HRMS) Q-Exactive Orbitrap system was used for the separation and detection of the contaminants. A targeted data independent acquisition (DIA) mode with an inclusion list with the exact mass, retention time window and collision energy was tried for the first time obtaining good sensitivity, selectivity and high quality MS2 product ions.•116 compounds of a wide-scope of polarities and physic-chemical properties were validated using a surface water pool matrix.•SPE followed by LCHRMS with a targeted DIA was used for the method validation at three concentration levels 5, 50, 500 μg l-1 in extract.•Good recoveries were obtained between 70 and 120% for the majority of the selected contaminants. Matrix effect, precision, and linearity were also evaluated and results proved the suitability for the method application.

Development of SFC-MS Method for Quantification of Eicosanoids Biosynthesized in Primary Human Blood Cells.

Eicosanoids are lipid mediators generated from arachidonic acid with pro- and anti-inflammatory properties. Despite these lipid mediators being known for decades, quantitative determination in biological samples is still challenging due to low abundance, instability, the existence of regio- and stereoisomers, and a wide polarity range that hampers chromatographic separation. In this study, we developed a supercritical fluid chromatography mass spectrometry (SFC-MS) platform for the quantification of relevant eicosanoids. Application of a chiral amylose-based column and modifier combination of 2-propanol/acetonitrile offered separation and sufficient resolution of 11 eicosanoids (5-, 12-, 15-HETE, PGB1, LTB4, t-LTB4, 20-OH-LTB4, PGE2, PGD2, PGF2α, TxB2) with baseline separation of isobaric analytes within 12 min. The method was validated in terms of range (78-2500 ng/mL), linearity, accuracy, precision, and recovery according to EMA guidelines. Finally, we confirmed the method's applicability by quantifying eicosanoid levels in human primary blood cells. In conclusion, we present a validated SFC-MS method for the determination of relevant eicosanoids in biological samples with a wide range of polarity while maintaining baseline separation of isobars, which allows coupling to a single quadrupole mass detector.

An Analytical Specialty Team Enabling Merck′s Pipeline with Pioneering Measurement Science

AbstractThis invited Team Profile was created by the above group. They recently published an article on the introduction of a hybrid separation technique, referred to as Dual‐Gradient Unified Chromatography (DGUC), enabling simultaneous multicomponent analysis of both small and large molecules across a wide polarity range in single experimental runs. DGUC lays the foundation for the next generation of hybrid chromatographic techniques with the deployment of universal elution profiles obtained via multi‐eluent blending beyond traditional separation modes. “Dual‐Gradient Unified Chromatography: A New Paradigm for Versatility in Simultaneous Multicomponent Analysis”, G. L. Losacco, R. Bennett, I. A. Haidar Ahmad, R. C. Barrientos, J. O. DaSilva, Y. Dong, A. W. Schuppe, Z. Wang, S. Aiken, I. Mangion, V. K. Aggarwal, E. L. Regalado, Angew. Chem. Int. Ed. 2022, e202208854; Angew. Chem. 2022, e202208854.

An Analytical Specialty Team Enabling Merck's Pipeline with Pioneering Measurement Science.

This invited Team Profile was created by the above group. They recently published an article on the introduction of a hybrid separation technique, referred to as Dual-Gradient Unified Chromatography (DGUC), enabling simultaneous multicomponent analysis of both small and large molecules across a wide polarity range in single experimental runs. DGUC lays the foundation for the next generation of hybrid chromatographic techniques with the deployment of universal elution profiles obtained via multi-eluent blending beyond traditional separation modes. "Dual-Gradient Unified Chromatography: A New Paradigm for Versatility in Simultaneous Multicomponent Analysis", G. L. Losacco, R. Bennett, I. A. Haidar Ahmad, R. C. Barrientos, J. O. DaSilva, Y. Dong, A. W. Schuppe, Z. Wang, S. Aiken, I. Mangion, V. K. Aggarwal, E. L. Regalado, Angew. Chem. Int. Ed. 2022, e202208854; Angew. Chem. 2022, e202208854.

Fabrication of a core-shell porphyrin-based magnetic covalent organic framework for effective extraction of PCPs in a wide polarity range

A novel porphyrin-based magnetic covalent organic framework (PCOF) was first reported by using a facile synthetic procedure. The Fe3O4@NH2@PCOF nanospheres were utilized to effectively extract personal care products in a wide polarity range (log Kow values from 1.96 to 7.60). The successful magnetic solid-phase extraction (MSPE) of target analytes could be ascribed to the sufficient oxygen-, nitrogen- and phenyl-containing functional groups of the COF layer, which are demonstrated to be of good compatibility with pollutants exhibiting different polarities by using molecular dynamics simulations, independent gradient model analysis and various characterizations. The MSPE extraction efficiency was enhanced by optimizing key parameters. The findings indicated that the method had a wide linearity range (1–500 ng mL−1 for parabens and UV filters) and low detection limits (0.4–0.9 ng mL−1 for parabens and 0.2–0.6 ng mL−1 for UV filters). The accuracy was reflected by recoveries ranging from 74% to 114%. Satisfactory intra- and inter-day precisions from 3.0% to 9.8% and 0.5%–9.1% were obtained. Overall, the proposed MSPE-HPLC method is accurate and reliable for identifying parabens as well as UV filters in wastewater and swimming pool water. The potential of the method for evaluating human exposure risk was unfolded.

From waste to health: Application of MOF modified walnut biochars for the determination of twenty pesticides in wheat flour by ultra-high performance liquid chromatography-tandem mass spectrometry

In this research, walnut shell along with a Ni-metal organic framework (Ni-MOF) was thermally treated to obtain a highly efficient biochar. A µ-solid phase extraction (µ-SPE) setup containing the optimized walnut modified biochar was implemented for the extraction of 20 wheat specified pesticides with a wide range of polarities. The modified biochars were characterized and the role of Ni-MOF on the porosity of the obtained biochars was investigated. After optimizing the extraction parameters, the 50 %-Ni-MOF-walnut shell biochar was selected. Accordingly, the precision for intra-day (2.4–25 %), inter-day (7–28.3 %) and synthesis procedure (4.1–26.7 %) was calculated. The limits of detection and quantification were in the range of 0.01–12.1 µg/L and 0.03–40.5 µg/L, respectively. This method was applied for the analysis of 29 wheat samples. The risk assessment study demonstrates that the contaminated wheat samples cannot cause non-carcinogenic harm to adults but might have an impact on children.

Dual-Gradient Unified Chromatography: A New Paradigm for Versatility in Simultaneous Multicomponent Analysis.

Generality in analytical chemistry can be manifested in impactful platforms that can streamline modern organic synthesis and biopharmaceutical processes. We herein introduce a hybrid separation technique named Dual-Gradient Unified Chromatography (DGUC), which is built upon an automated dynamic modulation of CO2 , organic modifier, and water blends with various buffers. This concept enables simultaneous multicomponent analysis of both small and large molecules across a wide polarity range in single experimental runs. After a careful investigation of its fundamental aspects, a DGUC-DAD-MS screening workflow that combines multiple orthogonal column and mobile phase choices across a far-reaching universal elution profile is also reported. The power of this framework is demonstrated with new analytical applications guiding academic and industrial laboratories in the development of new (bio)pharmaceutical targets (e.g. synthetic intermediates, nucleosides, cyclic and linear peptides, proteins, antibody drug conjugates).

Dual‐Gradient Unified Chromatography: A New Paradigm for Versatility in Simultaneous Multicomponent Analysis

AbstractGenerality in analytical chemistry can be manifested in impactful platforms that can streamline modern organic synthesis and biopharmaceutical processes. We herein introduce a hybrid separation technique named Dual‐Gradient Unified Chromatography (DGUC), which is built upon an automated dynamic modulation of CO2, organic modifier, and water blends with various buffers. This concept enables simultaneous multicomponent analysis of both small and large molecules across a wide polarity range in single experimental runs. After a careful investigation of its fundamental aspects, a DGUC‐DAD‐MS screening workflow that combines multiple orthogonal column and mobile phase choices across a far‐reaching universal elution profile is also reported. The power of this framework is demonstrated with new analytical applications guiding academic and industrial laboratories in the development of new (bio)pharmaceutical targets (e.g. synthetic intermediates, nucleosides, cyclic and linear peptides, proteins, antibody drug conjugates).

Structural Elucidation of Novel Stable and Reactive Metabolites of Green Tea Catechins and Alkyl Gallates by LC-MS/MS.

Synthetic gallic acid derivatives are employed as additives in food, personal care products, and pharmaceutical formulations. Despite their widespread use, little is known about their human exposure, health effects, and metabolism. Green tea catechins are natural antioxidants, known for their health-promoting properties, and are also employed as food additives or in personal care products. The objective of this study was to establish metabolic pathways involved in the biotransformation of green tea catechins and synthetic gallate esters. Liquid chromatography coupled with high-resolution tandem mass spectrometry (LC-HRMS/MS) was used to elucidate oxidative and methylated metabolites, in addition to glutathione conjugates, formed in vitro using human liver microsomal incubations. The developed method was applied to 14 different parent compounds with a wide range of polarities, for the structural elucidation of many known and novel metabolites. These results serve to inform about the wide variety of possible metabolites formed upon exposure to these compounds.

Development of analytical methods to study the salivary metabolome: impact of the sampling.

Advances in metabolomics have allowed the identification and characterization of saliva metabolites that can be used as biomarkers. However, discrepancies can be noted with the content of the same biomarker being increased or decreased for a given disease. Differences in the way saliva is collected, stored, and/or treated could cause these discrepancies. Indeed, there is no standardized method for saliva sampling and analysis. In this work, two chromatographic modes were used, i.e., RP-LC and HILIC both coupled to MS used in positive and negative ionization modes. The analytical conditions were optimized with a mixture of 90 compounds naturally present in saliva, representative of the wide range of molecular mass and polarity of salivary metabolites and being described as having a differential expression in various pathologies. These four methods were applied to the analysis of saliva samples collected by spitting, aspiration, or Salivette® with or without prior rinsing of the mouth. Rinsing had an effect on some metabolite concentrations. As it can induce an additional parameter of variability to the sampling, it seems therefore preferable to use methods without rinsing while effects of these parameters on the metabolites are investigated. Saliva obtained by spitting and aspiration gave statistically equivalent results for 84% of the metabolites studied. Conversely, Salivette® gave different results since the majority of the metabolites chosen for the study were not quantified in the samples. The Salivette® does not seem therefore to be a suitable sampling method for an untargeted analysis of the salivary metabolome, unlike aspiration and spitting.

Fractionation by flash chromatography and molecular characterization of bio-oil by ultra-high-resolution mass spectrometry and NMR spectroscopy

Bio-oils obtained from the pyrolysis of lignocellulosic biomass are highly complex matrices with tens of thousands of organic compounds covering a wide polarity and mass range. Their upgrading into greener fuel or value-added chemicals requires an in-depth knowledge of their molecular composition prior and after valorization treatment, which can be obtained by different analytical techniques. Here, flash chromatography was employed as an efficient way to fractionate a bio-oil vacuum residue into four distinct fractions. This process was repeatable at both gravimetric and chromatographic levels and provided information about the weight contribution of each fraction to bio-oil composition. Achieved fractions were then characterized by ultra-high-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and nuclear magnetic resonance spectroscopy. These two techniques ensured the good repeatability of bio-oil fractionation at the molecular level and also highlighted molecular specificities of each fraction. Thus, flash chromatography provided quantitative information that was complementary to FT-ICR MS results. It also simplifies the bio-oil compositional analysis, making it possible to detect more compounds. Eventually, this fractionation process can also be used to target fraction or compounds of interest for bio-oil upgrading.

Non-target screening of micropollutants and transformation products for assessing AOP-BAC treatment in groundwater

Standard monitoring programs give limited insight into groundwater status, especially transformation products (TPs) formed by natural processes or advanced oxidation processes (AOP), are normally underrepresented. In this study, using suspect and non-target screening, we performed a comprehensive analysis of groundwater before and after AOP by UV/H2O2 and consecutively installed biological activated carbon filters (BAC). By non-target screening, up to 413 compounds were detected in the groundwater, with an average 70% removal by AOP. However, a similar number of compounds were formed during the process, shown in groundwater from three waterworks. The most polar compounds were typically the most stable during the AOP. A subsequent BAC filter showed removal of 95% of the TPs, but only 46% removal of the AOP remaining precursors. The BAC removal for polar compounds was highly dependent on the acidic and basic functional groups of the molecules. 49 compounds of a wide polarity range could be identified by supercritical fluid chromatography (SFC) and liquid chromatography (LC) with high resolution mass spectrometry (HRMS); of these, 29 compounds were already present in the groundwater. To the best of our knowledge, five compounds have never been reported before in groundwater (4-chlorobenzenesulfonic acid, dibutylamine, N-phenlybenzenesulfonamide, 2-(methylthio)benzothiazole and benzothiazole-2-sulfonate). A further five rarely reported compounds are reported for the first time in Danish groundwater (2,4,6-trichlorophenol, 2,5-dichlorobenzenesulfonic acid, trifluormethansulfonic acid, pyrimidinol and benzymethylamine). Twenty of the identified compounds were formed by AOP, of which 10 have never been reported before in groundwater. All detected compounds could be related to agricultural and industrial products as well as artificial sweeteners. Whereas dechlorination was a common AOP degradation pathway for chlorophenols, the (ultra-) short chain PFAs showed no removal in our study. We prioritized 11 compounds as of concern, however, the toxicity for many compounds remains unknown, especially for the TPs.

The separation regularity of the three-phase solvent system of counter-current chromatography based on polarity parameter modeling

The three-phase solvent system of counter-current chromatography can separate compounds with a wide range of polarity, but there is no study of its separation regularity. Therefore, in this work, the separation regularity of the three-phase solvent system was initially investigated from the perspective of solvent polarities and compound polarities. The standard compounds covering a wide polarity range were selected, and three-phase solvent systems, n-hexane/methyl acetate/acetonitrile/water, and n-hexane/methyl tert-butyl ether/acetonitrile/water were used for modeling. The results showed that in the three-phase solvent system, the partition coefficient for the middle and lower phases (lgKM/L) increased with increasing logP values in three intervals logP < 0, 0 < logP < 4, and logP > 4. In addition, the partition coefficient for the upper and middle phases (lgKU/M) between the upper and middle phases of the small polarity compounds increases with increasing logP values. LogP vs lgKM/L of 7 solvent systems were employed for the smoothing spline fit through a predictive model design of the curve fitting toolbox in MATLAB software, and good results were achieved. LogP versus lgKM/L for n-hexane/methyl tert-butyl ether/acetonitrile/water solvent systems were used for the second-order power fit, and satisfactory results were obtained. The relationship between polarity parameters and separation case parameters was explored using a heat map approach. The separation regularity of the three-phase solvent system was preliminarily investigated. This regularity study gives hope of assistance to the chemists studying three-phase solvents and counter-current chromatography.

New insights into the Van Krevelen diagram: Automated molecular formula determination from HRMS for a large chemical profiling of lichen extracts.

In recent years, LC-MS has become the golden standard for metabolomic studies. Indeed, LC is relatively easy to couple with the soft electrospray ionization. As a consequence, many tools have been developed for the structural annotation of tandem mass spectra. However, it is sometimes difficult to do data-dependent acquisition (DDA), especially when developing new methods that stray from the classical LC-MS workflow. An old tool from petroleomics that has recently gained popularity in metabolomics, the Van Krevelen diagram, is adapted for an overview of the molecular diversity profile in lichens through high-resolution mass spectrometry (HRMS). A new method is benchmarked against the state-of-the-art classification tool ClassyFire using a database containing most known lichen metabolites (n ≈2,000). Four lichens known for their contrasted chemical composition were selected, and extractions with apolar, aprotic polar, and protic polar solvents were performed to cover a wide range of polarities. Extracts were analyzed with direct infusion electrospray ionization mass spectrometry (DI-ESI-MS) and atmospheric solids analysis probe mass spectrometry (ASAP-MS) techniques to be compared with the chemical composition described in the literature. The most common lichen metabolites were efficiently classified, with more than 90% of the molecules in some classes being matched with ClassyFire. Results from this method are consistent with the various extraction protocols in the present case study. This approach is a rapid and efficient tool to gain structural insight regarding lichen metabolites analyzed by HRMS without relying on DDA by LC-MS/MS analysis. It may notably be of use during the development phase of novel MS-based metabolomic approaches.

Pairing patterns in polarized unitary Fermi gases above the superfluid transition

We nonperturbatively study pairing in the high-temperature regime of polarized unitary two-component Fermi gases by extracting the pair-momentum distribution and shot-noise correlations. Whereas the pair-momentum distribution allows us to analyze the propagation of pairs composed of one spin-up and one spin-down fermion, shot-noise correlations provide us with a tomographic insight into pairing correlations around the Fermi surfaces associated with the two species. Assuming that the dominant pairing patterns right above the superfluid transition also govern the formation of condensates in the low-temperature regime, our analysis suggests that the superfluid ground state is homogeneous and of the Bardeen-Cooper-Schrieffer type over a wide range of polarizations.

Dissecting Solvent Effects on Hydrogen Bonding

AbstractThe experimental isolation of H‐bond energetics from the typically dominant influence of the solvent remains challenging. Here we use synthetic molecular balances to quantify amine/amide H‐bonds in competitive solvents. Over 200 conformational free energy differences were determined using 24 H‐bonding balances in 9 solvents spanning a wide polarity range. The correlations between experimental interaction energies and gas‐phase computed energies exhibited wild solvent‐dependent variation. However, excellent correlations were found between the same computed energies and the experimental data following empirical dissection of solvent effects using Hunter's α/β solvation model. In addition to facilitating the direct comparison of experimental and computational data, changes in the fitted donor and acceptor constants reveal the energetics of secondary local interactions such as competing H‐bonds.

Dissecting Solvent Effects on Hydrogen Bonding.

The experimental isolation of H‐bond energetics from the typically dominant influence of the solvent remains challenging. Here we use synthetic molecular balances to quantify amine/amide H‐bonds in competitive solvents. Over 200 conformational free energy differences were determined using 24 H‐bonding balances in 9 solvents spanning a wide polarity range. The correlations between experimental interaction energies and gas‐phase computed energies exhibited wild solvent‐dependent variation. However, excellent correlations were found between the same computed energies and the experimental data following empirical dissection of solvent effects using Hunter's α/β solvation model. In addition to facilitating the direct comparison of experimental and computational data, changes in the fitted donor and acceptor constants reveal the energetics of secondary local interactions such as competing H‐bonds.

Naphthalimide-Carbazole Compact Electron Donor-Acceptor Dyads: Effect of Molecular Geometry and Electron-Donating Capacity on the Spin-Orbit Charge Transfer Intersystem Crossing.

We prepared a series of naphthalimide (NI)-carbazole (Cz) compact electron donor-acceptor dyads showing different substitution positions, C-N/C-C linkers, and conformation restriction magnitudes to study the spin-orbit charge transfer intersystem crossing (SOCT-ISC). The varied conformation restrictions lead to different dihedral angles between the donor and acceptor (37°-81°) and electronic coupling magnitude (matrix elements V: 1290-3070 cm-1). Based on the comparison between the dyads containing C-N and C-C linkers, we found that a large dihedral angle between the donor and acceptor is favorable to efficient SOCT-ISC. For one dyad, the singlet oxygen quantum yield (ΦΔ) is up to 84.4% (in dichloromethane), which is much higher than that of the previously reported NI-phenothiazine (PTZ) analogue dyad (ΦΔ = 16.0% in n-hexane). The intrinsic triplet state lifetime (τT) is 270 μs, longer than that accessed by the heavy atom effect (75.2 μs). As compared with the NI-PTZ analogue dyad, the Cz unit in the current dyads is a weaker electron donor than PTZ. Thus, a higher CT state energy in NI-Cz dyads was observed, which makes the SOCT-ISC efficient in solvents with a wide range of polarities. Meanwhile, the localized triplet state (3LE) becomes the lowest-lying state in the NI-Cz dyads, which is different from the triplet charge transfer (3CT) state observed in the analogue NI-PTZ dyad. Moreover, the large energy gap between the CT and 3LE states inhibits the reverse ISC; as a result, no thermally activated delayed fluorescence was observed for the current NI-Cz dyads.

Screening of orange peel waste on valuable compounds by gradient multiple development diode-array high-performance thin-layer chromatography

High-performance thin-layer chromatography (HPTLC), as the modern form of TLC (thin-layer chromatography), is suitable for detecting pharmaceutically active compounds over a wide polarity range using the gradient multiple development (GMD) technique. Diode-array detection (DAD) in conjunction with HPTLC can simultaneously acquire ultraviolet‒visible (UV‒VIS) and fluorescence spectra directly from the plate. Visualization as a contour plot helps to identify separated zones. An orange peel extract is used as an example to show how GMD‒DAD‒HPTLC in seven different developments with seven different solvents can provide an overview of the entire sample. More than 50 compounds in the extract can be separated on a 6-cm HPTLC plate. Such separations take place in the biologically inert stationary phase of HPTLC, making it a suitable method for effect-directed analysis (EDA). HPTLC‒EDA can even be performed with living organism, as confirmed by the use of Aliivibrio fischeri bacteria to detect bioluminescence as a measure of toxicity. The combining of gradient multiple development planar chromatography with diode-array detection and effect-directed analysis (GMD‒DAD‒HPTLC‒EDA) in conjunction with specific staining methods and time-of-flight mass spectrometry (TOF‒MS) will be the method of choice to find new chemical structures from plant extracts that can serve as the basic structure for new pharmaceutically active compounds.

Phytochemical screening and proximate analysis of the leaf extracts of Vitex doniana

The method of cold maceration was used in the extraction by serial exhaustive extraction method which involves successive extraction with solvents of increasing polarity from a nonpolar (hexane) to a more polar solvent (methanol) to ensure that a wide polarity range of compound could be extracted. The phytochemical screening of the crude extract of Vitex doniana showed that flavonoids, steroids, phlobatannins, alkaloids, saponins were found to be present. Alkaloids were detected in the methanol, n-Hexane, acetone and ethyl acetate extracts when Wagner`s reagent was used. Flavonoids were detected in the methanol, hexane and acetone extracts when treated with NaOH and was present in all extracts with the exception of methanol extract when treated with lead acetate. Acetone extract indicated the presence of phlobatannins, but phlobatannins was absent in the hexane, ethyl acetate, and methanol extracts. Proximate analysis for the leaves of Vitex doniana revealed moisture content (7.04%), crude fibre (8.12%), crude protein (51.80%), ash (5.5%) fat (16.33%) and carbohydrate (11.21%) indicating high nutritional value.