Liquid Chromatography-tandem Quadrupole Mass Spectrometry Research Articles

Research Note: Pharmacokinetics of bromhexine hydrochloride in broilers after single oral and intravenous administration

The current study aimed to investigate the pharmacokinetics of bromhexine hydrochloride in broilers after single intravenous (IV) and oral (PO) administration at 2.5 mg/kg body weight (BW). The trial adopted a randomized, parallel-controlled design, where 20 twelve-wk-old broilers were randomly assigned to either the PO or IV group. Blood samples were collected at predetermined time points, and plasma was further separated for analysis. The bromhexine hydrochloride concentrations in plasma samples were determined using an ultra-performance liquid chromatography-tandem quadrupole mass spectrometry (UPLC-MS/MS) method. Noncompartmental analysis (NCA) using Phoenix software was conducted to analyze the concentration versus time data of bromhexine hydrochloride in every chicken. Subsequently, the main pharmacokinetic parameters between the 2 groups were statistically analyzed using SPSS software. Results from NCA revealed that after oral administration at 2.5 mg/kg BW, bromhexine hydrochloride exhibited slow absorption, reaching an average peak concentration of 32.72 ng/mL at 1.78 h. However, incomplete absorption was observed, with an absolute bioavailability of only 20.06% ± 10.84%. Additionally, bromhexine hydrochloride displayed wide distribution, with a steady-state distribution volume (VSS) of 22.55 ± 13.45 L/kg, and slow elimination, with a clearance (Cl) of 1.52 ± 0.38 L/h/kg. Furthermore, gender effects were assessed on the pharmacokinetics of bromhexine hydrochloride in broilers, revealing better absorption in male broilers compared to females. This disparity may be attributed to the faster blood flow and richer blood volume typically found in male broilers.

Analysis of 15 bile acids in human plasma based on C18 functionalized magnetic organic polymer nanocomposite coupled with liquid chromatography-tandem mass spectrometry

Because of the “enterohepatic circulation” of bile acid, liver damage can be reflected by monitoring the content of bile acid in the serum of the organism. To monitor the concentration of 15 bile acids in plasma samples, a new technique of PRiME (process, ruggedness, improvement, matrix effect, ease of use) pass-through cleanup procedure combined with high performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC-MS/MS) was developed. The sorbent used in the PRiME pass-through cleanup procedure is a new type of magnetic organic resin composite nano-material modified by C18 (C18-PS-DVB-GMA-Fe3O4), which has high cleanup efficiency of plasma samples. It also shows good performance in the separation and analysis of 15 kinds of bile acids. Under the optimal conditions, the results show higher cleanup efficiency of C18-PS-DVB-GMA-Fe3O4 with recoveries in the range of 82.1–115 %. The limit of quantitative (LOQs) of 15 bile acids were in the range of 0.033 µg/L-0.19 µg/L, and the RSD values of 15 bile acids were in the range of 3.00–11.9 %. Validation results on linearity, specificity, accuracy and precision, as well as on the application to analysis of 15 bile acids in 100 human plasma samples demonstrate the applicability to clinical studies.

Mass Spectrometric Methods for Evaluation of Voriconazole Avian Pharmacokinetics and the Inhibition of its Cytochrome P450-induced Metabolism

Invasive fungal aspergillosis is a leading cause of morbidity and mortality in many species including avian species such as common ravens (Corvus corax). Methods were developed for mass spectral determination of voriconazole in raven plasma as a means of determining pharmacokinetics of this antifungal agent. Without further development, GC/MS/MS (gas chromatography-tandem quadrupole mass spectrometry) proved to be inferior to LC/MS/MS (liquid chromatography-tandem quadrupole mass spectrometry) for measurement of voriconazole levels in treated raven plasma owing to numerous heat-induced breakdown products despite protection of voriconazole functional groups with trimethylsilyl moieties. LC/MS/MS measurement revealed in multi-dosing experiments that the ravens were capable of rapid or ultrarapid metabolism of voriconazole. This accounted for the animals’ inability to raise the drug into the therapeutic range regardless of dosing regimen unless cytochrome P450 (CYP) inhibitors were included. Strategic selection of CYP inhibitors showed that of four selected compounds including cimetidine, enrofloxacin and omeprazole, only ciprofloxacin (Cipro) was able to maintain voriconazole levels in the therapeutic range until the end of the dosing period. The optimal method of administration involved maintenance doses of voriconazole at 6 mg/kg and ciprofloxacin at 20 mg/kg. Higher doses of voriconazole such as 18 mg/kg were also tenable without apparent induction of toxicity. Although most species employ CYP2C19 to metabolize voriconazole, it was necessary to speculate that voriconazole might be subject to metabolism by CYP1A2 in the ravens to explain the utility of ciprofloxacin, a previously unknown enzymatic route. Finally, despite its widespread catalog of CYP inhibitions including CYP1A2 and CYP2C19, cimetidine may be inadequate at enhancing voriconazole levels owing to its known effects on raising gastric pH, a result that may limit voriconazole solubility.

Pharmacokinetics, Bioavailability, and Tissue Distribution of the Kirsten Rat Sarcoma Inhibitor Adagrasib in Rats Using UPLC-MS/MS.

Adagrasib is a selective and reversible inhibitor of KRAS G12C, which significantly delays the progression of solid tumors. However, the absorption, distribution, metabolism, and excretion of adagrasib in vivo are unclear. This study explores the absorption and distribution of adagrasib in vivo. An ultra-high performance liquid chromatography-tandem quadrupole mass spectrometry (UPLC-MS/MS) method was established for the determination of adagrasib in the rat plasma and tissue. Sprague-Dawley rats were intravenous administrated (5 mg/kg) and oral administrated (30 mg/kg) with adagrasib, and the plasma concentration of adagrasib was determined. After single oral administration of adagrasib (30 mg/kg), the heart, liver, spleen, lung, kidney, intestine, and pancreas were excised. The organs were homogenized with saline solution, and the concentration of adagrasib in tissues was determined. The intra- and inter-day accuracy were from 84.90% to 113.47%, and the precision was within ±15%. The matrix effect and recovery were within ±15%. The maximum plasma concentration (Cmax) of adagrasib was 677.45 ± 58.72 ng/mL. The elimination half-life time (t1/2) was 3.50 ± 0.21 h after oral administration and 2.08 ± 0.54 h after intravenous administration. The oral bioavailability was 50.72%. The highest concentrations of adagrasib in liver was 5047.80 ± 676.48 ng/g at 2 h after administration, and it was still detectable at 24 hours after administration. Adagrasib was slowly absorbed and cleared rapidly, and it was also widely distributed in vivo. This study provides a potential reference for adagrasib in clinical studies.

A Negative Association between Plasma Phylloquinone and All-Cause Mortality in Chinese Adults with Hypertension: A Nested Case-Control Study

BackgroundPrevious studies have revealed that vitamin K is essential for preventing various chronic diseases. Phylloquinone is the primary dietary and circulating form of vitamin K. However, data concerning the association between plasma phylloquinone and all-cause mortality are limited. ObjectivesThis study aimed to evaluate the association between plasma phylloquinone and risk of all-cause mortality and examine some potential confounders. MethodsThis study is a post hoc analysis of the RCT and a nested, case-control design was used. Enrolled participants had to have hypertension at baseline. Study initiation was 19 May, 2008, and the median follow-up was 4.5 y. A total of 604 mortality cases and 604 controls matched for age, sex, treatment group, and study site were included in this study. Odds ratios (OR) and 95% confidence intervals (CIs) of all-cause mortality were calculated using conditional or unconditional logistic regression, without or with adjusting for pertinent covariates, respectively. The concentration of phylloquinone was measured by liquid chromatography–tandem quadrupole mass spectrometry (LC-MS/MS). ResultsThe mean and median phylloquinone levels were 1.62 nmol/L and 0.89 nmol/L, respectively. There was a significant negative association between log-transformed plasma phylloquinone and all-cause mortality after controlling for potential confounders (per 1 unit increase-OR: 0.79; 95% CI: 0.66, 0.95). Furthermore, the association of plasma phylloquinone with risk of all-cause mortality differed by body mass index (BMI) (<25 kg/m2 compared with ≥25 kg/m2, P-interaction = 0.004). A significant trend of decreasing risk with increasing concentration of phylloquinone was observed in participants with higher BMI (per 1 unit increase-OR: 0.71; 95% CI: 0.56, 0.90; P = 0.004). No significant correlation was found between phylloquinone and risk of all-cause mortality in those with BMI <25 kg/m2. ConclusionsIn Chinese patients with hypertension, there was a significant negative association between baseline plasma phylloquinone and all-cause mortality, especially among those with higher BMI.

Analytical Techniques in Exploring the Persistent Global PFAS Problem

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals with unique properties. They are used in a wide range of different industries because they repel water and oil, and they are heat-resistant. However, PFAS contamination has become a widespread global concern because of their ubiquitous occurrence, persistence in the environment and living organisms, and potential health risks. Governments around the world are continuously introducing and updating regulatory limits for PFAS in drinking water, other types of water, biota, and, most recently, food. Analyzing such a wide range of sample types for PFAS requires high sensitivity and selectivity, typically provided by methods based on advanced liquid chromatography–tandem quadrupole mass spectrometry (LC–MS/MS) instrumentation. However, one critical aspect to sampling and analyzing PFAS accurately is to avoid PFAS contamination during these processes. This paper emphasizes the significance of robust and reliable PFAS analysis to support efforts to mitigate the global PFAS crisis. Collaboration, research, and advanced analytical solutions are essential to safeguard food, water, and the environment, thusly reducing the impact of PFAS on public health and the environment.

Assessing floor contamination by antineoplastic agents in a Japanese medical institution specializing in cancer treatment.

This study investigated the extent of contamination with antineoplastic agents on floor surfaces of the ward and the outpatient chemotherapy center of a Japanese cancer center to evaluate healthcare workers' risk of occupational exposure to antineoplastic agents outside of the designated drug preparation areas. In this study conducted at Aichi Cancer Center, the amount of fluorouracil detected on various floor surfaces was measured using liquid chromatography-tandem quadrupole mass spectrometry. Areas around the toilets were cleaned with a surfactant two or three times a day, whereas other floor surfaces were cleaned only with dry and wet mops. Fluorouracil was detected on all surveyed floor surfaces, with particularly high amounts detected around the toilet areas in the ward. Additionally, areas with more human traffic tended to have higher fluorouracil contamination. This survey suggested that antineoplastic agent contamination occurring through patient excretions might spread throughout the hospital with human traffic. Therefore, controlling the spread of antineoplastic agent contamination in hospitals should include the review of measures to mitigate contamination around toilets and to implement effective cleaning methods for floor surfaces.

Development of a specific and sensitive method for the detection of glyphosate pesticide and its metabolite in tea using dummy molecularly imprinted solid-phase extraction coupled with liquid chromatography-tandem quadrupole mass spectrometry

Glyphosate, a widely used herbicide, and its primary metabolite aminomethyl phosphonic acid have been found to cause environmental and ecological issues and threaten human health. The conventional pretreatment method was insufficient for the extraction, concentration, and enrichment of trace substances, resulting in poor specificity. Thus, our objective was to develop a method for glyphosate pesticide detection using dummy molecularly imprinted solid-phase extraction (DMI-SPE) combined with liquid chromatography-tandem quadrupole mass spectrometry (DMI-SPE-LC/MS/MS). The sol-gel method was used to prepare the molecularly imprinted material, using glyphosine as the dummy template molecule, to achieve specific adsorption to glyphosate and reduce costs. The optimized polymerization conditions achieved maximum adsorption of 28.6 µg/mg glyphosate by the molecularly imprinted material. The established DMI-SPE-LC/MS/MS method was used to detect glyphosate and its metabolite (aminomethyl)phosphonic acid in tea. The concentration ranges of glyphosate and (aminomethyl)phosphonic acid (from 0.05 to 4 µg/mL) were linear with correlation coefficients of 0.999 and 0.991, respectively. The recoveries of (aminomethyl)phosphonic acid at three spiked levels ranged from 79.95% to 83.74%, with RSDs between 6.40% and 7.45%, while the recoveries of glyphosate ranged from 98.69% to 106.26%, with RSDs between 0.91% and 1.18%. Our results demonstrate that the developed DMI-SPE-LC/MS/MS method achieves high sensitivity and specific detection of glyphosate and its metabolite (aminomethyl)phosphonic acid in tea matrices.

Preparation and application of nano petal-shaped covalent organic frameworks modified polystyrene-divinylbenzene- glycidylmethacrylate microspheres for the extraction of illicit drugs from wastewater

A novel nano petal-shaped covalent organic frameworks modified magnetic polystyrene-divinylbenzene-glycidylmethacrylate (NP-COF@Mag-PS/DVB/GMA) microsphere has been synthesized. It is a perfect combination of high productivity of PS/DVB/GMA microspheres and excellent enrichment efficiency of COF particles, and the excellent properties of NP-COF@Mag-PS/DVB/GMA microspheres are characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) and X-ray photoelectron spectroscopy (XPS). The sorbent can extract illicit drugs via the reverse-phase interactions provided by benzene ring on the polymer backbone and the hydrogen bonding interactions provided by functional group (-NH-) on the COF particles. Based on using NP-COF@Mag-PS/DVB/GMA as sorbents, an easiness-to-handle of magnetic dispersive solid phase extraction (Mag-dSPE) procedure is proposed for the simultaneous preconcentration of 12 illicit drugs from wastewater. The obtained results show high extraction efficiency of NP-COF@Mag-PS/DVB/GMA to illicit drugs with recoveries between 81.6 and 116%. Furthermore, a liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS) method for the determination of 12 illicit drugs from wastewater at sub-ppt levels has been proposed and validated with the pretreatment of samples by Mag-dSPE. The limits of quantification (LOQs) for the 12 illicit drugs are between 0.40 and 4.90 ng/L. Validation results on linearity, specificity, trueness and precision, as well as on application to the analysis of 12 illicit drugs in ten real samples demonstrate the applicability to environment monitoring analysis.

Enhanced therapeutic effect on colitis with powder formulations of Painong San associated with the promotion of intestinal adhesion and absorption

Ethnopharmacological relevancePainong San is a prescription composed of traditional Chinese medicine, which has been used to treat colitis. The Painong San's usage recorded in “Jingui Yaolve” by Zhongjing Zhang in the Later Han Dynasty is powder. However, the decoction is often used in reality. It's unclear which dosage form of Painong San is more suitable for colitis treatment and why? Aim of the studyThis study aims to evaluate the different therapeutic effects of Painong San (a powder of Painong San) and Painong Decoction (a decoction of Painong San) on a dextran sulfate sodium salt-induced colitis model and the possible reasons of these different effects. Materials and methodsThe contents of paeoniflorin, naringin, heperidin and neohesperidin in Painong San and Painong decoction were determined by an ultra-performance liquid chromatography system. The therapeutic effect on colitis was evaluated by intragastric administration of Painong San or Painong Decoction in dextran sulfate sodium salt-induced mouse model. The accumulated release rate of Painong San in vitro was analyzed with artificial gastric juice, artificial intestinal juice, and artificial colon juice. The concentrations of four compounds in the blood, intestinal contents, and intestinal fluids were detected by an-ultra performance liquid chromatography-tandem quadrupole mass spectrometry system. In situ intestinal perfusion experiments were used to observe the adhesion of Painong San to the intestine's surface. The expression of Mucin-2 and Trefoil Factor 3 in the colon was studied by immunohistochemistry. ResultsThere was no significant difference in the contents of the four compounds in Painong San and Painong Decoction. In vivo, Painong San has a better therapeutic effect than Painong Decoction in the treatment of colitis. Painong San could be released slowly in the simulated human digestion environment in vitro, and more Painong San particles were released on the intestinal surface in the colitis state in the healthy state. Painong San could increase the bioavailability of hesperidin and neohesperidin, and their concentrations in local intestinal tissue, intestinal fluid and intestinal contents. The expression of trefoil Factor 3 protein on the surface of the colon tended to be in the intestinal cavity and overlapped with the expression of mucin-2. Trefoil Factor 3 accumulates in the intestinal cavity of the colon in the state of colitis, which may increase the adhesion of Painong San particles. ConclusionIn conclusion, this experiment proved that Painong San is a more suitable dosage form for the treatment of dextran sulfate sodium salt-induced colitis than Painong Decoction, which may be related to the enhancement of Painong San particle adhesion to the intestine in colitis. This study provides a reference for the selection of clinical dosage forms for traditional Chinese medicine.

Method Validation for Simultaneous Quantification of Some High-risk Pesticides in Surface Water Samples by SPE-LC-MS/MS

ABSTRACT In this paper, a solid phase extraction procedure was developed for the simultaneous extraction of 22 multiclass high-risk pesticides, containing a variety of chemical groups (organophosphate, neonicotinoid, sulfonylurea, strobilurin, triazole, triazine, and acetanilide), from surface water samples. The target analytes extracted on the HLB SPE cartridge, and then eluted with acetonitrile with 5% (v/v) formic acid. The final sample solution was analysed by high-performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC–MS/MS) system. Under optimum conditions, good linearity was obtained for the target pesticides with correlation coefficient greater than 0.99. The limit of quantitation (LOQ) for the 22 pesticides was 0.1 ng/mL. The absolute recoveries of the pesticides from spiked water samples ranged from 70.0% to 121.5%. Relative standard deviations (RSD) for five replicate determinations were below 14.7%. The proposed method has been successfully applied to detect the presence of multiclass pesticides in environmental water samples.

A Forward-Thinking Approach to Addressing the New Synthetic Opioid 2-Benzylbenzimidazole Nitazene Analogs by Liquid Chromatography-Tandem Quadrupole Mass Spectrometry (LC-QQQ-MS).

Novel psychoactive substances (NPS) continue to represent a threat to public health and safety. The number of new drugs in the latest emergent synthetic opioid class—the 2-benzylbenzimidazole analogs—also called the nitazenes—has begun to dominate the current new synthetic opioid (NSO) subclass of NPS. We describe a liquid chromatography–tandem quadrupole mass spectrometry method for the quantification of nine analogs and/or metabolites of drugs in this series: isotonitazene, metonitazene, protonitazene, etonitazene, clonitazene, flunitazene, N-desethyl isotonitazene, 5-amino isotonitazene and 4ʹ-hydroxy nitazene in human whole blood, urine, and tissue. Samples were prepared for analysis using a basic liquid–liquid extraction. Chromatographic separation was achieved using a C-18 analytical column. Multiple reaction monitoring mode was used for detection. The calibration range for the analytes was 0.5–50 ng/mL (except for 5-amino isotonitazene, which was 1.0–50 ng/mL). The limit of detection was 0.1 ng/mL, and the limit of quantitation was 0.5 ng/mL. The method had no carryover or interferences. Ionization enhancement was observed but did not affect quantitation. All analytes passed the method validation assessment. Authentic human samples suspected of containing NSOs were obtained from a medical examiner and coroner offices, as well as partnering forensic toxicology laboratories. Isotonitazene was confirmed in 92 blood samples, and its metabolites were confirmed across various matrices. Metonitazene (n = 35), flunitazene (n = 5), protonitazene (n = 3), etodesnitazene (n = 2) and butonitazene (n = 1) were also detected in cases. These newly emerging 2-benzylbenzimidazole analogs were commonly found in combination with NPS benzodiazepines and opioids (e.g., flualprazolam, fentanyl). Nitazene analogs are potent esoteric drugs that may not be identified during routine toxicological screening, and specialized assays based on sensitive instrumentation are needed to accurately characterize these NSOs.

Ultratrace analysis of per- and polyfluoroalkyl substances in drinking water using ice concentration linked with extractive stirrer and high performance liquid chromatography – tandem mass spectrometry

Detection of drinking water contaminants is vital to the protection of human health. One group of contaminants that have recently generated serious concerns over health risks are per- and polyfluoroalkyl substances (PFAS). These compounds are very bio-persistent, leading to their detection in all types of water sources, including drinking water. While analysis of drinking water for PFAS is important, it is currently arduous to detect ultratrace levels of these contaminants. Specifically, current ultratrace PFAS analysis methods are difficult, costly, require large sample volumes, and consume relatively large volumes of organic solvent. In the present work, an analytical method using Ice Concentration Linked with Extractive Stirrer (ICECLES) and high performance liquid chromatography—tandem quadrupole mass spectrometry (HPLC-MS/MS), was developed and validated to provide simple and ultratrace analysis of drinking water for 14 PFAS. The method featured a relatively low sample volume requirement (10 mL), automated extraction, minimal matrix effects, and minimal organic solvent use (i.e., the method requires only 50 µL of methanol per sample). The method produced a wide linear range of 0.5 to 500 ng/L, ultratrace limits of detection (0.05 to 0.3 ng/L), and good accuracy and precision (i.e., 87 to 108% accuracy and ≤19% relative standard deviation as a measure of precision). This method was tested on drinking water samples from across the United States and detected at least one PFAS compound in 52 of the 53 drinking water samples tested. Perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), and perfluoroheptanoic acid (PFHpA) were detected in 89, 96, and 77% of the samples tested with maximum concentrations of 268 ng/L for PFHxA, 213 ng/L for PFOA, and 75.7 ng/L for PFHpA. Additionally, perfluorononanoic acid, perfluorodecanoic acid, and perfluoroheptanoic acid were each detected in at least one drinking water sample at concentrations > 20 ng/L. The availability of the method presented here allows ultratrace detection of PFAS while circumventing many of the disadvantages of current methods.

Pharmacokinetics of 10-Hydroxy Mesaconitine in Rat Plasma by Ultra-Performance Liquid Chromatography-Tandem Quadrupole Mass Spectrometry.

Mesaconitine is the predominant active ingredient in Aconitum carmichaelii Debx. The compound 10-hydroxy mesaconitine is one known metabolite of mesaconitine and is toxic. In order to better understand its pharmacokinetics, UPLC-MS/MS was used in this paper to measure the concentration of 10-hydroxy mesaconitine in the plasma of rats after oral (5 mg/kg) and intravenous (0.1 mg/kg) administration of 10-hydroxy mesaconitine. The concentrations of 10-hydroxy mesaconitine in rat plasma measured in the standard curve covered the range of 0.3–60 ng/mL. The intraday and interday precisions of the samples of 10-hydroxy mesaconitine in rat plasma were lower than 15%. In addition, the accuracies ranged between 96.0% and 109.3%, the matrix effects ranged between 88.9% and 98.1%, and the recoveries were all higher than 79.1%. The AUC(0 − t) values were 23.6 ± 5.9 and 207.6 ± 72.9 ng/mL·h for intravenous and oral administration, respectively, and the bioavailability of 10-hydroxy mesaconitine was 17.6%. Lastly, t1/2 was 1.3 ± 0.6 h and 3.1 ± 0.4 h for intravenous and oral administration, respectively.

Targeted Metabolomics Identifies Differential Serum and Liver Amino Acids Biomarkers in Rats with Alcoholic Liver Disease.

To investigate changes in serum and hepatic levels of amino acids in ALD and to provide novel evidence and approaches for the prevention and treatment of ALD. Twenty specific pathogen-free SD male rats were devided into two groups, ten for the control group, and ten for the model group. Serum biochemical markers, including alanine aminotransferase, aspartate aminotransferase, laminin and hyaluronidase were measured. Histological analysis of liver tissues was performed. Serum and liver amino acids levels were quantitatively determined by ultra-high-performance liquid chromatography-tandem quadrupole mass spectrometry (UPLC-TQMS)-based targeted metabolomics. Compared with the normal group, ALD rats showed an obvious increase in the levels of β-alanine, alanine, serine, ornithine, tyrosine and the tyrosine ratio, while there was a decrease in arginine levels, the BTR ratio and Fischer's ratio in serum. Additionally, ALD rats exhibited a significant increase in the levels of cysteine and putrescine, while there was a decrease in sarcosine, β-alanine, serine, proline, valine, threonine, ornithine, lysine, histidine, tyrosine, symmetric dimethylarginine, methionine, isoleucine and methionine-sulfoxide levels in liver tissues compared with the normal group. The serum and liver amino acids showed significant changes in ALD rats and can be considered as potential specific diagnostic biomarkers for ALD.

Preparation of sheet-like covalent organic frameworks and their application for efficient preconcentration of 4-(tert-octyl)-phenol and 4-nonylphenol in textiles

In the design of highly ordered (covalent organic frameworks) COFs with “ordered domains size and orientation” construction in a well-defined arrangement, the molecular monomers are the key factors. Here, the effect of molecular monomers on the construction of COFs has been studied, and two kinds of molecular monomers, i.e., ethanediamine (flexible amine ligand) and 4,4′-diaminobiphenyl (rigid amine ligand) have been used for developing sheet-like COFs-I and sheet-like COFs-II, respectively. Furthermore, they have been evaluated in the dispersive solid phase extraction (dSPE) procedure for textiles prior to the analysis of alkylphenol by liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS). The results showed that, the optimal usage amount of sheet-like COFs-II used in the dSPE procedure was less than that of sheet-like COFs-I, which may be explained by much higher adsorption capacity of sheet-like COFs via hydrogen-bonding and π-π stacking interactions. Rectilinear calibration graphs were obtained for 4-(tert-octyl)-phenol (4-tOP) and 4-nonylphenol (4-NP) in the range 0.2-20 µg/kg with determination coefficient (r2) higher than 0.9990, and the limits of detection (LODs) of 4-tOP and 4-NP were 0.039 µg/kg and 0.048 µg/kg, respectively. The developed method has been successfully applied to analysis of 50 textile samples, in which 4-tOP and 4-NP were found in six samples with concentrations in the range of 1.6 μg/kg-20.9 μg/kg.

Magnetic porous carbon derived from Zn/Co metal-organic framework as an adsorbent for extraction and determination of carbamates.

A novel magnetic porous carbon with a high specific surface and magnetization saturation, derived from a Zn/Co-MOF-5, was fabricated by direct carbonization of Zn/Co-MOF-5 without the need of additional carbon precursors under optimum pyrolysis temperature. The material was employed as an adsorbent for magnetic solid-phase extraction of four carbamates from water and tomato samples prior to high-performance liquid chromatography-tandem quadrupole mass spectrometry analysis. Under optimum conditions, the method displayed good linearity (r > 0.9987) within the concentration range 0.05-20ngmL-1 for water samples and 0.1-40ngg-1 for tomato samples. The limits of detection (S/N = 3) for the four carbamate pesticides were in the range 0.0006-0.013ngmL-1 for water samples and 0.001-0.01ngg-1 for tomato samples and satisfactory spiked recoveries in the range 86.1 to 109.1% were obtainedwith the relative standard deviation values from 2.1 to 14.0%. Graphical abstract.

Transcriptome analyses revealed the ultraviolet B irradiation and phytohormone gibberellins coordinately promoted the accumulation of artemisinin in Artemisia annua L.

BackgroundArtemisinin-based combination therapy has become the preferred approach for treating malaria and has successfully reduced malaria-related mortality. Currently, the main source of artemisinin is Artemisia annua L., and thus, it is of strategic importance to enhance artemisinin contents in A. annua plants. Phytohormones and illumination are known to be important external environmental factor that can have notable effects on the production of secondary metabolite. The activities of different hormones can be influenced to varying degrees by light, and thus light and hormones may jointly regulate various processes in plants. Here, we performed transcriptome and metabolome analyses revealed that ultraviolet B irradiation and phytohormone gibberellins coordinately promoted the accumulation of artemisinin in Artemisia annua.MethodsArtemisinin analysis was performed by ultra-high performance liquid chromatography-tandem quadrupole mass spectrometry (UPLC-ESI-QqQ-MS/MS). RNA sequencing, GO and KEGG enrichment analysis were applied to analyzing the differentially expressed genes (DEGs) under ultraviolet B irradiation and gibberellins treatments. Weighted gene co-expression network (WGCNA) analyzed the genes in artemisinin‑related modules and identified candidate hub genes in these modules.ResultsIn this study, we found that cross-talk between UV-B and GA induced processes leading to modifications in artemisinin accumulation. A total of 14,762 genes differentially expressed (DEGs) among different treatments were identified by transcriptome analysis. UV-B and GA treatments enhanced the accumulation of artemisinin by up-regulating the expression of the key artemisinin biosynthesis genes ADS and CYP71AV1. According to the high degree value and high expression level, a total of 84 co-expressed transcription factors were identified. Among them, MYB and NAC TFs mainly involved in regulating the biosynthesis of artemisinin. Weighted gene co-expression network analysis revealed that GA + UV in blue modules was positively correlated with artemisinin synthesis, suggesting that the candidate hub genes in these modules should be up-regulated to enhance artemisinin synthesis in response to GA + UV treatment.ConclusionOur study demonstrated the co-regulation of artemisinin biosynthetic pathway genes under ultraviolet B irradiation and phytohormone gibberellins treatment. The co-expression was analysis revealed that the selected MYB and NAC TFs might have regulated the artemisinin biosynthesis gene expression with ADS and CYP71AV1 genes. Weighted gene co-expression network analysis revealed that GA + UV treatment in blue modules was positively correlated with artemisinin synthesis. We established the network to distinguish candidate hub genes in blue modules might be up-regulated to enhance artemisinin synthesis in response to GA + UV treatment.

Extraction Optimization of Six Alkaloids and Four Lignans in Zanthoxylum armatum by Orthogonal Design and Ultra-fast Liquid Chromatography–tandem Quadrupole Mass Spectrometry

Alkaloids and lignans in Zanthoxylum armatum display important biological activities, but the quanitification method of alkaloids has not been reported. In this study, an effective extraction method was developed through an orthogonal design, and ten compounds in roots, stems, branches and leaves of Zanthoxylum armatum were simultaneously quantified by ultra-fast liquid chromatography–tandem quadrupole mass spectrometry (UFLC–MS/MS). The roots, stems, branches and leaves of Z. armatum were ultrasonically extracted with methanol (solvent–to–sample ratio 100 : 1, v/w) for 10 min. An UFLC–MS/MS method was developed with a gradient UFLC mobile phase and triple quadruple tandem mass spectrometry with electrospray ionization in the positive ion mode. The method was validated for linearity, precision, repeatability and accuracy. The limits of detection and quantification were within 0.01–7.5 and 0.04–30 ng/mL, respectively. The root samples collected from Tian’e County were abundant in N-methylanhydrotetrahydroberberrubine A, escholidine perchlorate and pinoresinol monomethyl ether, eudesminthe.

Ultrasound-assisted synthesis of clover-shaped nano-titania functionalized covalent organic frameworks for the dispersive solid phase extraction of N-nitrosamines in drinking water

In this study, three batches of nano-titania functionalized covalent organic frameworks were acquired depending on different solvothermal reaction stages (24 h, 48 h and 72 h), which were named as single roll-up shaped nano-titania functionalized COFs (SSTF-COFs), double roll-up shaped nano-titania functionalized COFs (DSTF-COFs) and clover-shaped nano-titania functionalized covalent organic framework (CSTF-COFs), respectively. After comparing their extraction performances, the more efficient and stable CSTF-COFs were selected as sorbent for the dispersive solid phase extraction (dSPE) of eight target N-nitrosamines in drinking water, followed by the determination with liquid chromatography-tandem quadrupole mass spectrometry (LC–MS/MS). Owing to the introduction of hydroxy groups, CSTF-COFs showed high extraction efficiency for N-nitrosamines with a wide range of polarities through hydrogen bonding interaction, hydrophobic interaction and hydrophilic interaction. Under optimum conditions, the developed method provided relatively low limits of detection (0.13–2.45 ng/L) and satisfactory recoveries (88.6–105.5%), with relative standard deviations (RSDs) less than 8.3%. Therefore, with the assistance of CSTF-COFs, trace levels of N-nitrosamines were quantitatively and sensitively determined in 31 out of 460 bottled drinking water samples in a sensitive and convenient way.