Triple Ion Research Articles

Single-Base Methylome Analysis of Sweet Cherry (Prunus avium L.) on Dwarfing Rootstocks Reveals Epigenomic Differences Associated with Scion Dwarfing Conferred by Grafting

Plant grafting using dwarfing rootstocks is one of the important cultivation measures in the sweet cherry (Prunus avium) industry. In this work, we aimed to explore the effects of the dwarfing rootstock “Pd1” (Prunus tomentosa) on sweet cherry ‘Shuguang2’ scions by performing morphological observations using the paraffin slice technique, detecting GA (gibberellin) and IAA (auxin) contents using UPLC-QTRAP-MS (ultra-performance liquid chromatography coupled with a hybrid triple quadrupole-linear ion trap mass spectrometer), and implementing integration analyses of the epigenome and transcriptome using whole-genome bisulfite sequencing and transcriptome sequencing. Anatomical analysis indicated that the cell division ability of the SAM (shoot apical meristem) in dwarfing plants was reduced. Pd1 rootstock significantly decreased the levels of GAs and IAA in sweet cherry scions. Methylome analysis showed that the sweet cherry genome presented 15.2~18.6%, 59.88~61.55%, 28.09~33.78%, and 2.99~5.28% methylation at total C, CG, CHG, and CHH sites, respectively. Shoot tips from dwarfing plants exhibited a hypermethylated pattern mostly due to increased CHH methylation, while leaves exhibited a hypomethylated pattern. According to GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis, DMGs (differentially methylated genes) and DEGs (differentially expressed genes) were enriched in hormone-related GO terms and KEGG pathways. Global correlation analysis between methylation and transcription revealed that mCpG in the gene body region enhanced gene expression and mCHH in the region near the TSS (transcription start site) was positively correlated with gene expression. Next, we found some hormone-related genes and TFs with significant changes in methylation and transcription, including SAURs, ARF, GA2ox, ABS1, bZIP, MYB, and NAC. This study presents a methylome map of the sweet cherry genome, revealed widespread DNA methylation alterations in scions caused by dwarfing rootstock, and obtained abundant genes with methylation and transcription alterations that are potentially involved in rootstock-induced growth changes in sweet cherry scions. Our findings can lay a good basis for further epigenetic studies on sweet cherry dwarfing and provide valuable new insight into understanding rootstock–scion interactions.

Sonocatalytic degradation of furazolidone using a heterogeneous triple ion synergy system of ZnFe2O4@ZIF-67 nanostructures: Physicochemical Characterization and degradation pathway

Heterogeneous sonocatalysis coupled with peroxydisulfate (PDS) activation is considered as a rapid advanced oxidation process for the degradation of emerging pharmaceutical pollutants. ZnFe2O4@ZIF-67 nanostructures (NSs) with commendable features including a high crystallinity, a narrow bandgap, and an outstanding specific surface, showed excellent sonocatalytic performance, PDS activation and stability. A novel triple ion synergistic system was used for the swift degradation of 60 mg/L furazolidone (FZD) from real contaminated water sources. A superior sonocatalytic degradation performance of FZD (94 %) by ZnFe2O4@ZIF-67/PDS/Ultrasound system was achieved under the optimal conditions of 20 mmol/L PDS and 0.4 g/L of the nanocomposite within 60 min. The e-/h+ pairs produced as a result of the sonoluminescence phenomenon in the ZnFe2O4@ZIF-67 NSs, with a bandgap of 1.86 eV, accelerated the redox reduction transform cycle of the Zn2+ /Zn, Fe3+/ Fe2+ and Co3+/ Co2+ pairs by generating a large number of oxidative radicals, leading to the enhanced degradation efficiency. Quenching tests illustrated that SO4•-,1O2, •OH radicals and surface oxidation–reduction reactions played a crucial role during FZD degradation. FZD degradation by-products were put forward using the LC-MS technique, and a plausible degradation pathway was suggested. The mineralization tests and the toxicity of generated intermediates of FZD degradation were also examined. Also, the stability and reusability results underscored the substantial proficiency of the above system to remediate real-pharmaceutical-contaminated-water sources, providing a practical approach for its industrial applications.

Characterization and comparison of metabolites in colostrum from yaks, buffaloes, and cows based on UPLC-QTRAP-MS metabolomics

Colostrum from yaks and buffaloes possesses substantial nutritional value, yet the complete array of metabolites within remains insufficiently elucidated. This study scrutinizes the metabolite profiles of yak, buffalo, and cow colostrum utilizing targeted metabolomics paired with ultra-performance liquid chromatography-tandem triple quadrupole linear ion trap mass spectrometry (UPLC-QTRAP-MS). The analysis detected 362 metabolites across all samples. Furthermore, 63, 77, and 46 differential metabolites were selected between yak and buffalo colostrum, yak and cow colostrum, and buffalo and cow colostrum, respectively. Yak colostrum notably contained higher concentrations of inositol, glycine, and carnitine, whereas buffalo colostrum was distinguished by a substantial presence of primary bile acids, which facilitate fat digestion. These findings offer profound insights into yak and buffalo colostrum, providing critical data to propel advancements in the dairy industry.

Understanding of the irradiation response of Cr-based ATF coatings using in-situ TEM

Although CrNb coated zirconium alloy materials are considered as ATF candidates with excellent oxidation resistance and mechanical properties, the irradiation response behavior under harsh and complex service conditions is still unrevealed. Here, we report the evolution of the microstructure of pure Cr and CrNb coatings with different Nb contents under simultaneous irradiation with Cr+-He+-H2+ triple ion beams at 633 K by using an advanced in-situ transmission electron microscope (TEM). The results show that CrNb coatings with high Nb content have better irradiation stability. Under high-temperature irradiation conditions, irradiation-induced oxidation and grain growth or crystallization are observed for both Cr-8 Nb with a nanocrystalline structure and Cr-18 Nb coatings with an almost amorphous structure, whereas Cr-37 Nb coatings maintains relatively intact in the amorphous phase after irradiation at a dose of 10 dpa. Based on the in-situ tracking of the microstructural evolution, it is revealed that the mechanism of irradiation-accelerated oxidation and crystallization of coatings originates from displacement cascades enhancing local atomic diffusion and rearrangement.

The effect of hydrogen co-injection on the microstructure of triple ion irradiated F82H

The reduced activation ferritic/martensitic steel F82H-IEA was studied through a systematic set of dual (Fe2++He2+) and triple (Fe2++He2++H+) ion irradiations to determine the effect of hydrogen co-injection with helium and radiation damage on the irradiated microstructure and in particular, cavity evolution. Irradiations were conducted in four distinct permutations from a set of nominal irradiation parameters of 50 dpa, 1 × 10–3 dpa/s, 500 °C, and 40/10 appm/dpa of H/He or 10 appm/dpa of He. A temperature series of dual and triple ions ranging from 400 to 600 °C was conducted where swelling values of 1.3–2.4x were obtained with the co-injection of hydrogen. A damage level (50 to 150 dpa) and damage rate (2.5 × 10–4 to 2.5 × 10–3 dpa/s) series were also conducted where hydrogen was again observed to cause a ∼1.2–1.8x increase in swelling in triple ion irradiation versus dual ions. The effect of hydrogen was also observed to increase the overall steady state swelling rate from 0.02%/dpa in dual ions to 0.034%/dpa under triple ions at 500 °C by 150 dpa. A final series of triple ion experiments was conducted at 450 °C and 500 °C at 80 appm/dpa of H where swelling was suppressed by 50% compared to the dual ion irradiated case due to over-nucleation of small bubbles. The effect of hydrogen on bubble nucleation was to stabilize higher densities of smaller helium bubbles possibly through increasing nucleation rates and reduction of the stable bubble radius. The effect on swelling was in the promotion of higher densities of larger voids experiencing bias-driven growth. Hydrogen was shown to have a moderate influence on the nucleation and growth of dislocation loops, although these effects appear to be convoluted by the changes in cavity microstructure dominating sink strength across conditions. Hydrogen co-injection was also loosely correlated with enhanced dissolution of M23C6 precipitates across temperature and damage level regimes.

Using broadly targeted plant metabolomics technology combined with network pharmacology to explore the mechanism of action of the Yishen Gushu formula in the treatment of postmenopausal osteoporosis in vivo

Ethnopharmacological relevanceYishen Gushu Formula (YSGSF) is composed of Epimedium, prepared Rehmannia, Drynaria, Eucommia, Dodder, ginseng, Astragalus, Ligusticum wallichii, Aucklandia and Panax notoginseng. It can improve bone mineral density by regulating bone metabolism. However, the mechanism of YSGSF in the treatment of Postmenopausal osteoporosis (PMOP) remains unclear. Aim of the studyThe compounds, targets, and molecular mechanisms of YSGSF in the treatment of PMOP were investigated using broad-spectrum target metabolomics from plants, combined with network pharmacology and animal studies, leading to a discussion on a novel approach to understanding YSGSF's action in PMOP treatment. Materials and methodsUsing ultra-performance liquid chromatography coupled with triple quadrupole-linear ion trap tandem mass spectrometry (UPLC-QTRAP-MS/MS) within a comprehensive targeted metabolomics framework, the active constituents of YSGSF were identified. This, alongside network pharmacology and molecular docking, facilitated the identification of critical signaling pathways and targets pertinent to YSGSF's therapeutic effect on PMOP. Subsequently, an animal model for PMOP was developed. Following intervention grouping, rats' weight changes were recorded; serum bone metabolic factors were assessed via ELISA; bone microstructure was examined using HE staining and Micro-CT; and key signaling pathway proteins and genes were analyzed through immunohistochemistry to validate YSGSF's potential mechanism in PMOP treatment. ResultsA total of 84 main active components of YSGSF were identified. The key signaling pathways affected by YSGSF in the treatment of PMOP were the TNF and IL-7 signaling pathways, closely related to TNF-α, IL-1β, c-jun and other protein targets. The results of animal experiments showed that YSGSF could downregulate the expression of TNF-a, IL-1β and c-Jun proinflammatory factors by regulating the TNF and IL-7 signaling pathways and regulate the inflammatory response, osteocyte differentiation and apoptosis to control the development of PMOP. ConclusionYSGSF activates the TNF-α and IL-7 signaling pathways in PMOP rats, reducing TNF-α and IL-1β levels, the c-Jun inflammatory response, and osteocyte differentiation and apoptosis, thus playing a significant role in treating PMOP.

Study on the Mass Spectrometry Cleavage Pattern of Quinolone Antibiotics.

Quinolone antibiotics are extensively used clinically for human treatment and in agriculture. However, improper and excessive use can lead to the persistence of quinolone residues in animal tissues, potentially accumulating in the human body and posing health risks. Investigating the correlation between mass spectrometry cleavage patterns and molecular structural features enhances the analytical framework for detecting trace or unknown impurities in quinolones. To collect data, we employed triple quadrupole linear ion trap mass spectrometry in electrospray positive ion mode. Primary mass spectrometry scanning was utilized to confirm parent ions, while secondary mass spectrometry scanning enabled the observation of fragment ions. The cleavage characteristics and pathways of the compounds were inferred from accurate mass-to-charge ratios obtained from both primary and secondary mass spectrometry. Under soft ionization conditions, the compounds generally exhibited characteristic fragment ions of [M+H-H2O]+, [M+H-CO]+, and [M+H-H2O-CO]+. Additionally, subtle variations were observed in each compound due to differences in modifying groups. For instance, upon deacidification, the piperazine ring structure underwent breakage and rearrangement, yielding fragment ion peaks devoid of neutral molecules such as C2H5N, C3H7N, or C4H8N. Notably, compounds featuring a cyclopropyl substituent group at the N-1 position typically exhibited characteristic fragments resulting from the loss of the cyclopropyl radical (⋅C3H5). Moreover, substituents at the N-1 and C-8 positions, when linked to form a six-membered carbocyclic ring, were prone to cleavage, releasing the neutral C3H6 molecule. Quinolone antibiotics share structural similarities in their parent nuclei, leading to partially similar cleavage pathways. Nevertheless, distinct cleavage patterns emerge due to variations in functional groups. According to the difference of mass spectrometry cleavage patterns, it can provide an identification basis for the measured detection of antibiotics.

Cation-Binding of Glutamate in Aqueous Solution.

Interactions of the cations Li+, Na+, Mg2+, and Ca2+ with L-glutamate (Glu-) in aqueous solution were studied at room temperature with dielectric relaxation spectroscopy in the gigahertz region. Spectra of ∼0.4 M NaGlu with added LiCl, NaCl, MgCl2, or CaCl2 (c(MCln) ≤ 1.5 M) were evaluated and experiments supplemented by density functional theory and 3D reference interaction site model (3D-RISM) calculations. In addition to the modes found for aqueous NaGlu, namely, the reorientation of free Glu- ions (peaking at ∼1.6 GHz), of moderately retarded H2O molecules hydrating the carboxylate moieties of Glu- (∼8.4 GHz), of the cooperative resettling of the H-bond network of bulk water (∼20 GHz), and its preceding fast H-bond flip (∼400 GHz), an additional low-frequency relaxation at ∼0.4 GHz was detected upon the addition of the four salts. In the case of NaGlu + MgCl2(aq) and NaGlu + CaCl2(aq), this mode could be unequivocally assigned to an ion pair formed by the cation and the side-chain carboxylate moiety of Glu-. For NaGlu + LiCl(aq), either this species or a backbone-[Li+-H2O-Cl--Glu-] triple ion is formed. Binding constants increase in the order Li+<Mg2+<Ca2+. For NaGlu + NaCl(aq), an assignment of the ∼0.4 GHz mode to ion pairs or triples was not plausible. Accordingly, its origin remains speculative here.

Borneol acts as an adjuvant agent to enhance the oral absorption of Panax notoginseng saponins in rats: Effect of optical configuration and compatibility ratios

Ethnopharmacological relevancePanax notoginseng saponins (PNS), as the main active component of Panax notoginseng, shows broad pharmacological effects but with low oral bioavailability. Borneol (BO) is commonly used as an adjuvant drug in the field of traditional Chinese medicine, which has been proven to facilitate the absorption of ginsenosides such as Rg1 and Rb1 in vivo. The presence of chiral carbons has resulted in three optical isomers of BO commercially available in the market, all of which are documented by national standards. Aim of the studyThis study aimed to investigate the role of BO in promoting the oral absorption of PNS from the perspective of optical configuration and compatibility ratios. Materials and methodsIn this study, an ultra-performance liquid chromatography coupled with triple quadrupole-linear ion trap tandem mass spectrometry (UPLC-QTRAP-MS/MS) method was validated and applied to determine the concentrations of five main saponins in PNS in rat plasma. The kinetic characteristics of PNS were compared when co-administered with BO based on optical isomerism and different compatibility ratios. ResultsThe results showed that BO promoted the exposure of PNS in rats. Three forms of BO, namely d-borneol (DB), l-borneol (LB), and synthetic borneol (SB), exhibited different promotion strengths. SB elevated PNS exposure in rats more than DB or LB. It is also interesting to note that under different compatibility ratios, SB can exert a strong promoting effect only when PNS and BO were combined in a 1:1 ratio (PNS 75 mg/kg; BO 75 mg/kg). As a pharmacokinetic booster, the dosage of BO is worthy of consideration and should follow the traditional medication principles of Chinese medicine. ConclusionsThis study shed new light on the compatible use of PNS and BO from the perspective of “configuration-dose-influence” of BO. The results provide important basis for the clinical application and selection of BO.

Metabolite identification of salvianolic acid A in rat using post collision-induced dissociation energy-resolved mass spectrometry

BackgroundAs one of the most famous natural products, salvianolic acid A (SAA) is undergoing clinical trials for the treatments of angina pectoris and coronary heart disorders. However, the in vivo metabolites of SAA have only been tentatively identified, leading to a barrier for precise therapeutical drug monitoring.MethodsUltra-high performance liquid chromatography coupled with quadrupole time of flight tandem mass spectrometry (UPLC–Qtof-MS/MS) was firstly employed to acquire high-resolution MS1 and MS2 spectra for all metabolites. Through paying special attention onto the features of ester bond dissociation, metabolism sites were restricted at certain regions. To further determine the metabolism site, such as the monomethylated products (M23, M25, and M26), post collision-induced dissociation energy-resolved mass spectrometry (post-CID ER-MS) was proposed through programming progressive exciting energies to the second collision chamber of hybrid triple quadrupole-linear ion trap mass spectrometry (Qtrap-MS) device.ResultsAfter SAA oral administration, 29 metabolites (M1–M29), including five, thirteen, and sixteen ones in rat plasma, urine, and feces, respectively, were detected in rats. The metabolism route was initially determined by applying well-defined mass fragmentation pathways to those HR-m/z values of precursor and fragment ions. Metabolism site was limited to SAF- or DSS-unit based on the fragmentation patterns of ester functional group. Through matching the dissociation trajectories of concerned 1st-generation fragment ions with expected decomposition product anions using post-CID ER-MS strategy, M23 and M25 were unequivocally assigned as 3'-methyl-SAA and 3''-methyl-SAA, and M26 was identified as 2-methyl-SAA or 3-methyl-SAA. Hydrolysis, methylation, glucuronidation, sulfation, and oxidation were the primary metabolism channels being responsible for the metabolites' generation.ConclusionTogether, the metabolism regions and sites of SAA metabolites were sequentially identified based on the ester bond dissociation features and post-CID ER-MS strategy. Importantly, the present study provided a promising way to elevate the structural identification confidence of natural products and metabolites.Graphical abstract

Pseudotargeted metabolomics method and its application in erastin-stimulated gastric adenocarcinoma cells based on liquid chromatography with tandem mass spectrometry

Erastin, a classical ferroptosis inducer, exerts cytotoxicity in several types of cancer cells including gastric cancer cells. However, the mechanism of erastin in regulating metabolic pathways in gastric cancer remains largely unclear. To investigate the gastric cellular response to erastin therapy, a pseudotargeted metabolomics method was achieved on ultra-high performance liquid chromatography-hybrid triple quadrupole linear ion trap mass spectrometry (UHPLC-QTRAP MS), which was used to investigate metabolic changes between erastin-treated MGC-803 cells and the controls at different time points. We found that erastin induced tremendous impact on the metabolome of gastric cells by affecting key metabolic processes, such as cysteine and methionine metabolism, tryptophan metabolism, purine metabolism, glutathione biosynthesis, glycolysis and TCA cycle. Interestingly, S-adenosylmethionine, methionine, serine and cysteine were obviously increasing treads after erastin treatment, while S-adenosylhomocysteine and glutathione were always down-regulated up to 24 h. The results indicated that DNA methylation was activated and glutathione biosynthesis was blocked in erastin-treated MGC-803 gastric cells, highlighting the importance of erastin as a promising drug candidate for in vivo treatment of gastric tumor.

Plasma metabolomics identifies S-adenosylmethionine as a biomarker and potential therapeutic target for vascular aging in older adult males

Brachial-ankle pulse wave velocity (baPWV) is a noninvasive index of vascular aging. However, the metabolic profile underlying vascular aging has not yet been fully elucidated. The current study aimed to identify circulating markers of vascular aging as assessed by baPWV and to elucidate its mechanism from a metabolomic perspective in older adults. A total of 60 and 61 Chinese male participants aged ≥80 years were recruited to the metabolome and validation cohorts, respectively. The baPWV of participants was measured using an automatic waveform analyzer. Plasma metabolic profile was investigated using ultra-performance liquid chromatography coupled with triple quadrupole linear ion trap tandem mass spectrometry. Orthogonal partial least squares (OPLS) regression modeling established the association between metabolic profile and baPWV to determine important metabolites predictive of vascular aging. Additionally, an enzyme-linked immunosorbent assay was employed to validate the metabolites in plasma and culture media of vascular smooth muscle cells in vitro. OPLS modeling identified 14 and 22 metabolites inversely and positively associated with baPWV, respectively. These 36 biomarkers were significantly enriched in seven metabolite sets, especially in cysteine and methionine metabolism (p <0.05). Notably, among metabolites involved in cysteine and methionine metabolism, S-adenosylmethionine (SAM) level was inversely related to baPWV, with a significant correlation coefficient in the OPLS model (p <0.05). Furthermore, the relationship between SAM and vascular aging was reconfirmed in an independent cohort and at the cellular level in vitro. SAM was independently associated with baPWV after adjustments for clinical covariates (β = −0.448, p <0.001) in the validation cohort. In summary, plasma metabolomics identified an inverse correlation between SAM and baPWV in older males. SAM has the potential to be a novel biomarker and therapeutic target for vascular aging.

The impact of stoichiometry on the initial steps of crystal formation: Stability and lifetime of charged triple-ion complexes.

Minerals form in natural systems from solutions with varying ratios of their lattice ions, yet non-stoichiometric conditions have generally been overlooked in investigations of new formation (nucleation) of ionic crystals. Here, we investigated the influence of cation:anion ratio in the solution on the initial steps of nucleation by studying positively and negatively charged triple ion complexes and subsequent particle size evolution. Our model systems are carbonates and sulfates of calcium and barium, as it was recently shown that solution stoichiometry affects the timing and rate of their nucleation. Molecular dynamics (MD) simulations and dynamic light scattering (DLS) flow experiments show that nucleation correlates with the stability and lifetime of the initial complexes, which were significantly impacted by the cation:anion stoichiometry and ion type. Specifically, was found to have higher association constants and its lifetime was twofold longer than . Similar trends were observed for and . Contrastingly, for , was found to have lower association constants and its lifetime was shorter than . These trends in stability and lifetime follow the same asymmetrical behaviour as observed experimentally for particle formation using techniques like DLS. This suggests a causal relationship between the stability and lifetime of the initial charged complexes and the nucleation under non-stoichiometric conditions.

Breakdown Characteristics of GaN DMISFETs Fabricated via Mg, Si and N Triple Ion Implantation.

Mg-ion-implanted layers in a GaN substrate after annealing were investigated. Implanted Mg atoms precipitated along the edges of crystal defects were observed using 3D-APT. The breakdown characteristics of a GaN double-diffused vertical MISFET (DMISFET) fabricated via triple ion implantation are presented. A DMISFET with Si-ion-implanted source regions was formed in Mg-ion-implanted p-base regions, which were isolated from adjacent devices by N-ion-implanted edge termination regions. A threshold voltage of -0.5 V was obtained at a drain voltage of 0.5 V for the fabricated vertical MISFET with an estimated Mg surface concentration of 5 × 1018 cm-3. The maximum drain current and maximum transconductance in a saturation region of Vds = 100 V were 2.8 mA/mm and 0.5 mS/mm at a gate voltage of 15 V, respectively. The breakdown voltage in the off-state was 417 V. The breakdown points were determined by the boundary regions between the N- and Mg-implanted regions. By improving heat annealing methods, ion-implanted GaN DMISFETs can be a promising candidate for future high-voltage and high-power applications.

Dimethyl Ether Carbonylation on H-MOR Zeolite, Modified Cu, Co, Mg

Mordenite and ferrierite (Zeolyst International, H-form, SiO2/Al2O3 ≈ 20) were used to study the adsorption, thermally programmed desorption, and carbonylation of dimethyl ether (DME). The behavior of mordenite with Cu, Co, and Mg cations introduced by ion exchange has also been studied. DME carbonylation was carried out at 200°C, pressure 3 MPa, space velocity 8000 ml g–1 h–1 in a mixture, vol. %: ⁓2.2 DME, 92.8–95.5 CO, rest. N2. After the induction period, the methyl acetate content is about 4–5 times higher for mordenite compared to ferrierite. The formation of water, methanol and hydrocarbons was observed in small quantities. The introduction of Cu, Co, Mg cations into mordenite by ion exchange (single ion exchange, cation/Al ratio no more than 35%) not only increased the stability, but also increased the activity in the DME carbonylation reaction. It was found that an increase in the content of copper (from 1.19 to 2.23 wt %) and Mg (from 0.62 to 1.8 wt %) differently affects the activity. In the case of copper, an increase in activity was observed, while in the case of magnesium, the activity decreased. Preliminary reduction of copper-exchange mordenite leads to a decrease in activity and the appearance of metallic copper particles on the surface of mordenite crystallites. According to in situ diffuse reflectance infrared spectroscopy, the introduction of magnesium cations by triple ion exchange leads to a noticeable decrease in the number of Brønsted acid sites (BACs) in both the 12-MR and 8-MR channels of mordenite. The catalytic characteristics of ferrierite practically do not change when copper and magnesium are introduced by ion exchange.

Ultraviolet photodissociation and collision-induced dissociation for qualitative/quantitative analysis of low molecular weight compounds by liquid chromatography-mass spectrometry

Collision-induced dissociation (CID) is the most wildly used fragmentation technique for qualitative and quantitative determination of low molecular weight compounds (LMWC). Ultraviolet photodissociation (UVPD) has been mainly investigated for the analysis of peptides and lipids while only in a limited way for LMWC. A triple quadrupole linear ion trap instrument has been modified to allow ultraviolet photodissociation (UVPD) in the end of the q2 region enabling various workflows with and without data-dependent acquisition (DDA) combining CID and UVPD in the same LC–MS analysis. The performance of UVPD, with a 266-nm laser, is compared to CID for a mix of 90 molecules from different classes of LMWC including peptides, pesticides, pharmaceuticals, metabolites, and drugs of abuse. These two activation methods offer complementary fragments as well as common fragments with similar sensitivities for most analytes investigated. The versatility of UVPD and CID is also demonstrated for quantitative analysis in human plasma of bosentan and its desmethyl metabolite, used as model analytes. Different background signals are observed for both fragmentation methods as well as unique fragments which opens the possibility of developing a selective quantitative assay with improved sample throughput, in particular for analytes present in different matrices.Graphical

Floating plastics as integrative samplers of organic contaminants of legacy and emerging concern from Western Mediterranean coastal areas

This study investigates the role of floating plastics as integrative samplers of organic contaminants. To this end, plastics items were collected in two Western Mediterranean coastal areas: the Mar Menor lagoon, and the last transect of Ebro river. Floating plastics were identified and characterized by attenuated total reflection Fourier-transform infrared spectrometry. Then, organic contaminants were extracted from plastic items by ultrasonic extraction with methanol, and the concentrations of 168 regulated and emerging contaminants were analysed. These compounds were analysed by stir bar sorptive extraction coupled to gas chromatography–mass spectrometry (GC–MS), except for bisphenol analogues, which were analysed with a ultraperformance liquid chromatography pump coupled to a triple quadrupole mass spectrometer (UHPLC-MS/MS), and pharmaceutical compounds, determined by UPLC coupled to hybrid triple quadrupole-linear ion trap mass spectrometer (UPLC-MS/MS). All the contaminants groups considered were detected in the samples, being particularly relevant the contribution of plastic additives. The most frequently detected contaminants were UV-filters, PAHs, pharmaceuticals and synthetic musks. Apart from plasticizers, the individual contaminants octocrylene, homosalate, galaxolide, salycilic acid and ketoprofen were frequently detected in plastics items. The results pointed out to urban and touristic activities as the main sources of pollution in the coastal areas investigated. The utility of floating plastics as integrative samplers for the detection of organic contaminants in aquatic ecosystems has been demonstrated.

Quality evaluation of Lysimachiae Herba from different habitats based on simultaneous determination of multiple bioactive constituents combined with multivariate statistical analysis

A method based on ultra-high performance liquid chromatography coupled with triple quadrupole linear ion trap-tandem mass spectrometry(UHPLC-QTRAP-MS/MS) was developed for the simultaneous determination of 41 bioactive constituents of flavonoids, organic acids, nucleosides, and amino acids in Lysimachiae Herba. The content of multiple bioactive constituents was compared among the samples from different habitats. The chromatographic separation was performed in a Waters XBridge®C_(18) column(4.6 mm×100 mm, 3.5 μm) at 30 ℃. The gradient elution was performed with 0.4% methanol(A)-formic acid water(B) as the mobile phase at a flow rate of 0.8 mL·min~(-1), and the multiple-reaction monitoring(MRM) mode was adopted. According to the content of 41 constituents, hierarchical cluster analysis(HCA), orthogonal partial least squares discriminant analysis(OPLS-DA), and gray relational analysis(GRA) were perfomed to comprehensively evaluate the samples from different habitats. The results showed that the 41 constituents exhibited good linear relationship within the tested concentration ranges, with the correlation coefficients(r) greater than 0.999 4. The method featured good precision, repeatability, and stability with the relative standard deviations(RSDs) less than 5.0%. The average recoveries of the 41 constituents ranged from 98.06% to 101.9%, with the RSDs of 0.62%-4.6%. HCA and OPLS-DA separated 48 batches of Lysimachiae Herba samples from different habitats into three categories: the producing areas in Sichuan and Chongqing, the producing areas in Jiangsu, Zhejiang, and Jiangxi, and the producing areas in Guizhou. The content of 41 constituents varied among the Lysimachiae Herba samples from different habitats. The GRA results revealed that the Lysimachiae Herba sample from Nanchong City, Sichuan Province had the best comprehensive quality. The method developed in this study was accurate and reliable and thus can be used for comprehensive evaluation of Lysimachiae Herba quality and provide basic information for the selection of habitats.

Plasma metabolomic signatures of breast cancer.

Breast cancer is a common malignant tumor. A large number of medical evidence shows that breast cancer screening can improve the early diagnosis rate and reduce the mortality rate of breast cancer. In the present study, a wide range of targeted metabolomics profiling was conducted to investigate the plasma signatures of breast cancer. A total of 86 patients with benign breast abnormalities (L group) and 143 patients with breast cancer (E group) were recruited. We collected their plasma samples and clinical information. Metabolomic analysis, based on the coverage of a wide range of targeted metabolomics was conducted with ultraperformance liquid chromatography- triple quadrupole-linear ion trap mass spectrometer (UPLC-QTRAP-MS). We identified 716 metabolites through widely-targeted metabolomics. Serotonergic synapse was the main different metabolic pathway. The fold change of 14 metabolites was considered significantly different (fold change <0.67 or fold change >2; p < 0.05). By combining all the 14 metabolites, we achieved differentiation of L group vs. E group (AUC = 0.792, 95%Cl: 0.662-0.809). This study provided new insights into plasma biomarkers for differential diagnosis of benign abnormalities and breast cancer.

LC-MS/MS-MS3 for the Determination and Quantification of Δ9-Tetrahydrocannabinol and Metabolites in Blood Samples.

Due to the high prevalence of cannabinoids in forensic toxicology analysis, it is crucial to have an efficient method that allows the use of a small sample amount and that requires a minimal sample preparation, for the determination and quantification of low concentrations. A simple, highly selective and high throughput liquid chromatography tandem mass spectrometry methodology (LC-MS/MS-MS3) was developed for the determination and quantification of ∆9-tetrahydrocannabinol (THC), 11-hydroxy-∆9- tetrahydrocannabinol (THC-OH) and 11-nor-9-carboxy-∆9-tetrahydrocannabinol (THC-COOH), in blood samples. Chromatographic analysis of THC, THC-OH, and THC-COOH and their deuterated internal standards was preceded by protein precipitation (PPT) of 0.1 mL of blood samples with acetonitrile. Chromatographic separation was achieved by use of an Acquity UPLC® HHS T3 (100 mm x 2.1mm i.d., 1.8 μm) reversed-phase column, using a gradient elution of 2 mM aqueous ammonium formate, 0.1% formic acid, and methanol at a flow rate of 0.4 mL/min, with a run time of 10 minutes. For the MS/MS-MS3 analysis, a SCIEX QTRAP® 6500+ triple quadrupole linear ion trap mass spectrometer was used via electrospray ionization (ESI), operated in multiple reaction monitoring (MRM) and linear ion trap mode (MS3). The method was validated in accordance with internationally accepted criteria and guidelines, and proved to be selective and linear between 0.5-100 ng/mL (r2>0.995). The lower limits of quantification (LLOQ) corresponded to the lowest concentrations used for the calibration curves. The coefficients of variation obtained for accuracy and precision were <15%. The mean recoveries were between 88.0-117.2%, for the studied concentration levels (1 ng/mL, 5 ng/mL and 50 ng/mL). No significant interfering compounds, matrix effects or carryover were observed. The validated method provides a sensitive, efficient and robust procedure for the quantification of cannabinoids in blood, using LC-MS/MS-MS3 and a sample volume of 0.1 mL. This work is also a proof of concept for using LC-MS3 technique to determine drugs in biological samples.