Liquid Chromatography-triple Quadrupole Mass Spectrometry Research Articles

Determination of 107 typical pesticides and metabolites in raw water and drinking water by online-solid phase extraction coupled with ultra performance liquid chromatography-triple quadrupole mass spectrometry

In order to monitor the risk of pesticide pollutants in drinking water, an analytical method based on online-solid phase extraction coupled with ultra performance liquid chromatography-triple quadrupole mass spectrometry (online-SPE-UPLC-MS/MS) was established for the simultaneous rapid screening and determination of 107 pesticides and metabolites (organophosphorus, organic nitrogen, organic heterocycle, carbamate, amide, benzoyl urea, neonicotinoid, etc.) in raw water and drinking water. Different injection volumes (5, 10, and 15 mL) were compared. The detection response increased with an increase in the injection volume, but the matrix effect also became more pronounced. Under the premise of ensuring the sensitivity of the method and meeting the detection requirements, the injection volume was selected as 5 mL. Accordingly, the samples were filtered through a 0.22-μm hydrophilic polytetrafluoroethylene filter, and then, 5 mL samples were injected into the online-SPE system by the automatic sampler. After adsorption on an X Bridge C18 online-SPE column, the samples were washed with pure water and eluted by gradient elution using acetonitrile and 0.1% formic acid aqueous solution as the mobile phases, with separation on an ACQUITY HSS T3 column. The samples were detected by multiple reaction monitoring with electrospray ionization in positive and negative ion modes, and quantified by an external standard method. Using raw water and drinking water as the sample matrices, the accuracy and precision of the method were verified. The 107 pesticides and metabolites showed good linear relationships in different ranges with correlation coefficients (r2)>0.995. The limits of detection (LODs, S/N=3) of the method were 0.03-1.5 ng/L, and the limits of quantification (LOQs, S/N=10) were 0.1-5.0 ng/L. The target pesticides were spiked at concentration levels of 1, 20, and 50 ng/L. The spiked recoveries of the 107 targets in raw water and drinking water samples were 60.6%-119.8% and 61.2%-119.0%, respectively. The corresponding relative standard deviations (RSDs, n=6) were 0.3%-18.6% and 0.4%-17.1%. The pesticide residues in raw water and drinking water were determined by this method. Amide herbicides, triazine herbicides, triazole insecticides, carbamate insecticides, and neonicotinoid insecticides had high detection rates. The detected concentrations ranged from 0.1 to 97.1 ng/L in raw water and from 0.1 to 93.6 ng/L in drinking water. The sample consumption of online-SPE method was lower than that in the traditional off-line SPE methods, which greatly improved the convenience of sample collection, storage, and transportation. The samples only need to be filtered before injection and analysis. The method is simple to operate and shows good reproducibility. With this online-SPE method, only 23 min were required from online enrichment to detection completion. The developed method has the advantages of high analytical speed and high sensitivity. The method is suitable for the trace analysis and determination of 107 typical pesticides in raw water and drinking water, which effectively improves the detection efficiency of pesticides in water and has high potential for practical application. It can extend technical support for the pollution-level analysis of typical pesticides and metabolites in drinking water and provide an objective basis for human health risk assessment.

Establishment and application of a screening method for 354 organic toxicants in blood and urine with high-performance liquid chromatography-high-resolution orbitrap mass spectrometry.

A rapid and sensitive high-performance liquid chromatography-high-resolution orbitrap mass spectrometry method was developed for the simultaneous screening of 354 organic poisons and metabolites in blood and urine, including drugs, medications, pesticides, rodenticides, veterinary drugs, alkaloids, and mycotoxins with a multi-toxicant chromatography-mass spectrometry information library. The method and library showed good prospects in clinical poisoning screening and forensic toxicological identification. Blood and urine samples were extracted successively with ethyl acetate in acidic and alkaline conditions; then, the extract was blown to nearly dry by nitrogen gas and redissolved with methanol-aqueous solution (v:v, 50:50), and the dissolved solution was analyzed by LC-MS/MS after filtering. Precursor ions' m/z was set for identification, retention time, fragment ions, and isotopic pattern which were used for confirmation. No interference peaks were found in the blank samples, showing good specificity. The LODs of toxicants in urine and blood were 1.00×10-3-50.0 ng/mL and 2.07×10-3-50.0 ng/mL, respectively, while the LOQs were 3.30×10-3-1.67×102 ng/mL and 6.91×10-3-1.67×102 ng/mL. The intra-day precision and inter-day precision of urine samples were 2.31-9.13% and 4.75-12.3%, respectively, which were 1.92-10.8% and 2.01-12.1% in blood samples. The established method was applied to analyze 9 cases of clinical poisoning patients, and bromadiolone, carbofuran, and amanitins were detected, respectively. A total of 382 biospecimens from drug abusers were analyzed with the proposed method, which indicated that some drugs were detected in 62 cases, mainly including methamphetamine, heroin, and MDMA. The results were consistent with the information from traditional liquid chromatography-triple quadrupole mass spectrometry.

Optimized ultra-high-performance liquid chromatography tandem mass spectrometry method for detecting compositional changes in Eucommia ulmoides and Achyranthes bidentata paired decoctions in vitro and in vivo

AbstractRationaleThe bark of Eucommia ulmoides and the roots of Achyranthes bidentata are commonly used in traditional Chinese medicine, and their pairing appears in many traditional Chinese medicine formulas as a recognized compatible unit. However, the changes and interactions of the main components of these two formulas when paired remain unclear, and there is currently no standard or method for their quality control and assessment of pharmacological effects.MethodsAn optimized ultra-high-performance liquid chromatography triple-quadrupole mass spectrometry (UHPLC-MS/MS) method was established for the simultaneous identification of 10 components in E. ulmoides and A. bidentata using in vitro and in vivo models. Tributyltin methacrylate was the internal standard solution, and the blood samples were treated by an organic solvent precipitation method. Gradient elution was conducted on a C18 column at 25 °C with 0.1% formic acid water:acetonitrile as the mobile phase at a flow rate of 0.5 mL min−1. Dynamic multiple response monitoring was performed in negative-ion mode using an Agilent Jet Stream electrospray ionization ion source.ResultsIn negative-ion detection mode, eucommiol exhibited a good response, and the isomers ginsenoside Ro and achyranthoside C could also be well separated. The developed method accurately detected the five components with a low blood content. Compared to controls, the levels of ginsenoside Ro, chikusetsusaponin Ⅳa, and achyranthoside C increased; the contents of geniposidic acid and pinoresinol diglucoside were unchanged; and the levels of eucommiol, geniposide, β-ecdysterone, genipin, and achyranthoside D decreased in vitro. In vivo, the contents of geniposidic acid, geniposide, pinoresinol diglucoside, and β-ecdysterone were reduced; the contents of eucommiol and ginsenoside Ro were unchanged; and those of achyranthoside D, chikusetsusaponin Ⅳa, and achyranthoside C increased compared to the corresponding levels in the internal control.ConclusionsA method for the quality control of the E. ulmoides-A. bidentata drug pair was established for the first time and the main components in 10 drug pairs could be determined simultaneously in vitro and in vivo. These findings show that the E. ulmoides and A. bidentata drug pair cause a compositional change, providing new ideas for the development of this combination to improve clinical efficacy.

PEGylated Strontium Sulfite Nanoparticles with Spontaneously Formed Surface-Embedded Protein Corona Restrict Off-Target Distribution and Accelerate Breast Tumour-Selective Delivery of siRNA.

As transporters of RNAi therapeutics in preclinical and clinical studies, the application of nanoparticles is often hindered by their susceptibility to opsonin-mediated clearance, poor biological stability, ineffectual targeting, and undesirable effects on healthy cells. Prolonging the blood circulation time while minimizing the off-target distribution and associated toxicity is indispensable for the establishment of a clinically viable delivery system for therapeutic small interfering RNAs (siRNAs). Herein, we report a scalable and straightforward approach to fabricate non-toxic and biodegradable pH-responsive strontium sulfite nanoparticles (SSNs) wrapped with a hydrophilic coating material, biotinylated PEG to lessen unforeseen biological interactions. Surface functionalization of SSNs with PEG led to the generation of small and uniformly distributed particles with a significant affinity towards siRNAs and augmented internalization into breast cancer cells. A triple quadrupole liquid chromatography-mass spectrometry (LC-MS) was deployed to identify the proteins entrapped onto the SSNs, with the help of SwissProt.Mus_musculus database. The results demonstrated the reduction of opsonin proteins adsorption owing to the stealth effect of PEG. The distribution of PEGylated SSNs in mice after 4 h and 24 h of intravenous administration in breast tumour-bearing mice was found to be significantly less to the organs of the reticuloendothelial system (RES) and augmented accumulation in the tumour region. The anti-EGFR siRNA-loaded PEG-SSNs exerted a significant inhibitory effect on tumour development in the murine breast cancer model without any significant toxicity to healthy tissues. Therefore, PEGylated SSNs open up a new avenue for tumour-selective efficient delivery of siRNAs in managing breast cancer.

The Changes in Cyanobacterial Concentration of β-Methylamino-L-Alanine during a Bloom Event

β-N-methylamino L-alanine (BMAA) is a neurotoxin linked to high incidences of neurodegenerative disease. The toxin, along with two of its common isomers, 2,4-diaminobuytric acid (2,4-DAB) and N-(2-aminoethyl)glycine (AEG), is produced by multiple genera of cyanobacteria worldwide. Whilst there are many reports of locations and species of cyanobacteria associated with the production of BMAA during a bloom, there is a lack of information tracking changes in concentration across a single bloom event. This study aimed to measure the concentrations of BMAA and its isomers through the progression and end of a cyanobacteria bloom event using liquid chromatography-triple quadrupole-mass spectrometry. BMAA was detected in all samples analysed, with a decreasing trend observed as the bloom progressed. BMAA's isomers were also detected in all samples, however, they did not follow the same decreasing pattern. This study highlights the potential for current sampling protocols that measure a single time point as representative of a bloom's overall toxin content to underestimate BMAA concentration during a bloom event.

Quantification and purification of procyanidin B1 from food byproducts.

The flavan-3-ols of 10 primarily plant food byproducts, including MuscatHamburg grape seed, hawthorn sarcocarp, litchi pericarp, cocoa bean, peanut skin, lotus seedpod, Xinyang Maojian green tea, Cinnamomi cortex, Sargentodoxa cuneata stem, and Cyperus esculentus, leaves were analyzed. Ultrahigh-performance liquid chromatography-triple quadrupole mass spectrometry was used for the analysis. Cyperus esculentus leaves contained a high amount of procyanidin B1 (198.9mg/100g), second only to MuscatHamburg grape seed (292.9mg/100g). Unlike grape seed that contained several procyanidin B isomers with very similar retention times, C. esculentus leaves contained primarily procyanidin B1 with few isomers. Procyanidin B1 was enriched in the ethyl acetate fraction of a 70% methanol extract of C. esculentus leaves and purified at 95% purity by two runs of open column chromatography. Direct chromatography of the plant extract on octadecylsilane and Sephadex LH20 open columns improved the yield of the resultant leaf procyanidin B1 (95% purity) to 0.21‰. The present research demonstrated that the leaves of C. esculentus, byproducts of tigernut, are ideal plant sources for isolating and providing high-purity procyanidin B1. PRACTICAL APPLICATION: Procyanidin B1 has a broad range of health benefits. Cyperus esculentus is cultivated in many countries with nearly 6190 square hectares (hm2 ) in the Spanish Mediterranean region in 2020-2021 and over 16,700 hm2 in China in recent years, primarily for its tubers. The byproducts, the leaves of C. esculentus, contain high levels of procyanidin B1, with few isomers that interfere with its isolation and purification. Thus, the leaves of this plant provide a viable source for preparing high-purity procyanidin B1.

Residue behavior and risk assessment of pyraclostrobin and tebuconazole in peppers under different growing conditions.

This study evaluates the residue behavior and risks of pyraclostrobin and tebuconazole in peppers. An analytical method for the simultaneous determination of the concentration of these fungicides in peppers was developed using ultra-high performance liquid chromatography-triple quadrupole mass spectrometry. Pepper samples were extracted with acetonitrile and cleaned with primary secondary amine and graphitized carbon black. The average recoveries of pyraclostrobin and tebuconazole under three fortification levels were 86.7-101.4% and 81.7-104.4%, with relative standard deviations of 4.0-7.2% and 3.8-10.9%, respectively. The limit of quantification of both fungicides in peppers was 0.01mg/kg. The terminal residue trial of 30% pyraclostrobin and tebuconazole suspension concentrate was investigated for samples cultivated in open fields and greenhouses. The results showed that the terminal residues of pyraclostrobin and tebuconazole in peppers were lower than the maximum residue limits established by GB 2763-2021 (0.5mg/kg for pyraclostrobin and 2mg/kg for tebuconazole). The results of a statistical t-test indicated that there was no significant difference between samples grown in open fields and greenhouses. According to the international estimate of short-term intake (IESTI) calculation model, provided by the Joint FAO/WHO Meeting on Pesticide Residues, the acute dietary exposure risk of both fungicides in peppers was acceptable for the general population, with an IESTI of 0-3% and 0-5% of the acute reference dose for pyraclostrobin and tebuconazole, respectively.

Untargeted and targeted mass spectrometry reveal the effects of theanine on the central and peripheral metabolomics of chronic unpredictable mild stress-induced depression in juvenile rats

l-theanine has been shown to have a therapeutic effect on depression. However, whether l-theanine has an excellent preventive effect on depression in children and adolescents and what its mechanism is have not been well explained. Given the complexity of the pathogenesis of depression, this study investigated the preventive effect and mechanism of l-theanine on depression in juvenile rats by combining serum and hippocampal metabolomic strategies. Behavioral tests, hippocampal tissue sections, and serum and hippocampal biochemical indexes were studied, and the results confirmed the preventive effect of l-theanine. Untargeted reversed-phase liquid chromatography-quadrupole-time-of-flight mass spectrometry and targeted hydrophilic interaction liquid chromatography-triple quadrupole mass spectrometry were developed to analyze the metabolism changes in the serum and hippocampus to screen for potential biomarkers related to l-theanine treatment. The results suggested that 28 abnormal metabolites in the serum and hippocampus that were considered as potential biomarkers returned to near-normal levels after l-theanine administration. These biomarkers were involved in various metabolic pathways, mainly including amino acid metabolism and lipid metabolism. The levels of amino acids and neurotransmitters in the phenylalanine, tryptophan, and glutamic acid pathways were significantly reduced after l-theanine administration compared with chronic unpredictable mild stress-induced rats. In summary, l-theanine had a significant preventive effect on depression and achieved its preventive results on depression by regulating various aspects of the body, such as amino acids, lipids, and inflammation. This research systematically analyzed the mechanism of l-theanine in preventing depression and laid the foundation for applying l-theanine to prevent depression in children and adolescents.

Photocatalytic sol-gel/P25 TiO2 coatings for water treatment: Degradation of 7 selected pharmaceuticals

The effect of different water matrices on the photocatalytic degradation of dissolved pharmaceuticals was explored. The focus was on the degradation efficiencies in wastewater effluent from a bioreactor and water effluent from a central wastewater treatment plant and comparing the results with degradation in deionized H2O. The compounds tested included: oxytetracycline, marbofloxacin, ibuprofen, diclofenac, phenytoin, ciprofloxacin, sulfamethoxazole. For the experiments performed in this study, a compact packed-bed photocatalytic reactor was used in which the hybrid TiO2 photocatalyst (sol-gel/P25) was deposited on ∼3 mm glass beads. As expected, the reactions proceed more slowly in wastewater than in deionized water, yet it is shown that removal of the compounds from the water is still possible even when other organic molecules are present. Total organic carbon measurements have shown that complete mineralization takes place albeit at slower rates than the initial degradation of parent compounds. The results show that an acidic pH can increase the reaction rates and the adsorption on the photocatalyst surface. Analyses of the degradation intermediates were performed using tandem liquid chromatography triple-quadrupole mass spectrometry system. Additionally, X-ray absorption spectroscopy was applied to get insight into the local structure of the photocatalyst before and after use. Understanding the effects that different wastewater compositions have on photocatalytic reactions will help to refine the potential applications of the technology.

Residue levels and risk assessment of pesticides in litchi and longan of China

A total of 57 pesticide residues were analyzed in 155 litchis and 153 longan samples collected from the three main producing provinces of China. They were studied by the QuEChERS extraction method based on analysis using ultra performance liquid chromatography–triple quadrupole mass spectrometry (UPLC–MS/MS) and gas chromatography (GC) techniques. Health risks from litchis and longans for humans were evaluated by hazard quotient (HQ) and hazard index (HI). Sixteen different pesticides were detected in litchi samples. In longan samples, 19 different pesticides were detected. A total of 72% litchi samples and 52% longan samples contained at least one pesticide residue. Carbendazim, chlorbenzuron and diflubenzuron were found in 25.2%, 28.4%, and 34.8% of the litchi samples, respectively, and 21.6%, 11.8%, and 21.6% of the longan samples, respectively. The banned pesticides carbofuran and omethoate were detected in two litchi samples and one longan sample, respectively. Residue concentrations did not exceed the maximum residue levels (MRLs) in all litchi and longan samples except for carbofuran. Dietary risk assessment results showed that the chronic and acute dietary risks (HQc and HQa) of individual pesticides and the cumulative chronic dietary risks (HIc) of all pesticide residues for adults and children were all less than 100%. However, the cumulative acute dietary risk (HIa) of all pesticide residues from litchi samples for children was 99.85%, which was close to the unacceptable level and should be given more attention. The contributions of insecticide to HIc and HIa were 89.3% and 87.3% in litchi samples and 91.7% and 55.0% in longan samples.

Development and validation of an LC-MS/MS methodology for the quantification of thyroid hormones in dko MCT8/OATP1C1 mouse brain

The Allan-Herndon Dudley Syndrome (AHDS) is a rare disease caused by the progressive loss of monocarboxylate transporter 8 (MCT8). In patients with AHDS, the absence of MCT8 impairs transport of thyroid hormones (TH) through the blood brain barrier, leading to a central state of TH deficiency. In mice, the AHDS is mimicked by simultaneous deletion of the TH transporters MCT8 and the solute carrier organic anion transporter family member 1c1 (OATP1C1). To support preclinical mouse studies, an analytical methodology was developed and successfully applied for quantifying selected thyroid hormones in mouse whole brain and in specific regions using liquid chromatography tandem mass-spectrometry (LC-MS/MS). An important requirement for the methodology was its high sensitivity since a very low concentration of THs was expected in MCT8/OATP1C1 double-knockout (dko) mouse brain. Seven THs were targeted: L-thyroxine (T4), 3,3´,5‐triiodo‐L‐thyronine-thyronine (T3), 3,3´,5´‐triiodo‐L‐thyronine-thyronine (rT3), 3,3´‐diiodo‐L‐thyronine (3,3´‐T2, T2), 3,5-diiodo-L-thyronine (rT2, 3,5-T2), 3-iodo-L-thyronine (T1), 3-iodothyronamine (T1AM). Isotope dilution liquid chromatography triple-quadrupole mass spectrometry methodology was applied for detection and quantification. The method was validated in wild-type animals for mouse whole brain and for five different brain regions (hypothalamus, hippocampus, prefrontal cortex, brainstem and cortex). Instrumental calibration curves ranged from 0.35 to 150 pg/µL with good linearity (r2 >0.996). The limit of quantification was from 0.08 to 0.6 pg/mg, with an intra- and inter-day precision of 4.2–14.02% and 0.4–17.9% respectively, and accuracies between 84.9% and 114.8% when the methodology was validated for the whole brain. In smaller, distinct brain regions, intra- and inter-day precision were 0.6–20.7% and 2.5–15.6% respectively, and accuracies were 80.2–128.6%. The new methodology was highly sensitive and allowed for the following quantification in wild-type mice: (i) for the first time, four distinct thyroid hormones (T4, T3, rT3 and 3,3´‐T2) in only approximately 100 mg of mouse brain were detected; (ii) the quantification of T4 and T3 for the first time in distinct mouse brain regions were reported. Further, application of our method to MCT8/OATP1C1 dko mice revealed the expected, relative lack of T3 and T4 uptake into the brain, and confirmed the utility of our analytical method to study TH transport across the blood brain barrier in a preclinical model of central TH deficiency.

Waste coal cinder catalyst enhanced electrocatalytic oxidation and persulfate advanced oxidation for the degradation of sulfadiazine.

Waste coal cinder, a kind of waste cinder discharged from coal combustion of thermal power plants, industrial and civil boilers, and other equipment, was rich in metal oxides with catalytic activity. In this work, waste coal cinder was used to enhance electrochemical coupling peroxymonosulfate (PMS) advanced oxidation degradation of sulfadiazine (SD). The surface morphology, elemental composition, and electrocatalytic activity of waste coal cinder were characterized by various characterization instruments. The results show that compared with simple electrocatalytic oxidation, electrocatalytic oxidation+waste coal cinder and electrocatalytic coupled persulfate oxidation, electrocatalytic oxidation+PMS advanced oxidation+waste coal cinder has the largest removal efficiency (99.95%) and mineralization rates (90.16%) of SD in 90min, indicating that the introduction of waste coal cinder greatly increases the degradation efficiency. •OH and SO4-• were detected during the process of degradation. The optimal degradation process parameters were explored through different voltage, pH, plate spacing, aeration flow rate, potassium peroxymonosulfate sulfate complex salt dose, and Na2SO4 dosage. Cycling experiments show waste coal cinder has good structural stability. Through the analysis of triple quadrupole liquid chromatography-mass spectrometry (LC-MS), we put forward three possible ways of SD degradation. This research will provide a novel vision for water treatment.

Application of Mass Spectrometry for Determining the Geographic Production Area of Wagyu Beef.

Japanese Black cattle (Japanese Wagyu) beef is attracting attention for its aroma and marbling, and its handling is increasing worldwide. Here, we focused on the origin discrimination of Wagyu beef and analyzed the nutritional components of Japanese Wagyu (produced in multiple prefectures of Japan), Hybrid Wagyu (a cross between Angus and Wagyu cattle born in Australia and transported to Japan), and Australian Wagyu beef using mass spectrometry (MS). Triple-quadrupole liquid chromatography–MS was used to clarify the molecular species of lipids in Wagyu beef. Fourteen classes of lipids were separated, and 128 different triacylglycerides (TGs) were detected. A simple comparative analysis of these TGs using high-performance liquid chromatography revealed significantly higher levels of triolein (C18:1/C18:1/C18:1; abbreviated OOO) and C18:1/C18:1/C16:1 (OOPo) in Japanese Wagyu. Wagyu elements beef were comprehensively analyzed using inductively coupled plasma (ICP)–MS and ICP–optical emission spectrometry. We found significant differences in the rubidium, cesium, and lithium levels of Japanese and Australian Wagyu beef. On comparing metabolites using gas chromatography–MS, we identified significant differences in the levels of amino acids and other components of the Japanese and Australian Wagyu beef. These results suggest the possibility of determining the origin of Wagyu cattle breeds using MS and genetic discrimination.

Serum lipidomics profiles reveal potential lipid markers for prediabetes and type 2 diabetes in patients from multiple communities.

Dyslipidemia is a hallmark of diabetes mellitus (DM). However, specific lipid molecules closely associated with the initiation and progression of diabetes remain unclear. We used a pseudotargeted lipidomics approach to evaluate the complex lipid changes that occurred long before the diagnosis of type 2 diabetes mellitus (T2DM) and to identify novel lipid markers for screening prediabetes mellitus (PreDM) and T2DM in patients from multiple communities. Four hundred and eighty-one subjects consisting of T2DM, three subtypes of PreDM, and normal controls (NC) were enrolled as discovery cohort. Serum lipidomic profiles of 481 subjects were analyzed using an ultrahigh performance liquid chromatography-triple quadrupole mass spectrometry (UHPLC-QqQ-MS)-based pseudotargeted lipidomics method. The differential lipid molecules were further validated in an independent case-control study consisting of 150 PreDM, 234 T2DM and 94 NC. Multivariate discriminative analyses show that lipidomics data have considerable potential for identifying lipidome differences among T2DM, subtypes of PreDM and NC. Statistical associations of lipid (sub)species display significant variations in 11 lipid (sub)species levels for T2DM and distinctive differences in 8 lipid (sub)species levels between prediabetic and normoglycemic individuals, with further differences in 8 lipid (sub)species levels among subtypes of PreDM. Adjusted for sex, age and BMI, only two lipid (sub)species of fatty acid (FA) and phosphatidylcholine (PC) were associated at p< 0.05 for PreDM (all) and subtypes of PreDM. The defined lipid markers not only significantly improve the diagnostic accuracy of PreDM and T2DM but also effectively evaluating the risk of developing into each subtype of PreDM and T2DM when addition of age, sex, BMI, and FPG, respectively. Our findings improve insights into the lipid metabolic complexity and interindividual variations among subtypes of PreDM and T2DM, beyond the well-known differences in dyslipidemia in clinic.

Pharmacokinetics and metabolites of glycosides and lignans of the stem bark of Magnolia officinalis in functional dyspepsia and normal rats using liquid chromatography-tandem mass spectrometry.

The stem bark of Magnolia officinalis is a traditional Chinese medicine for the treatment of abdominal distention and functional dyspepsia. The pharmacokinetics of three glycosides (magnoloside A, magnoloside B, and syringin) and two lignans (honokiol and magnolol) in both normal and functional dyspepsia rats were firstly investigated by ultra-performance liquid chromatography-triple quadrupole mass spectrometry method and the influences of the coexisting compounds on the pharmacokinetic parameters of honokiol and magnolol were also studied. It was found that all of the five target compounds were quickly absorbed and eliminated in both normal and functional dyspepsia rats, while, their residence time was significantly decreased in pathological states except magnoloside A. The coexisting compounds in the stem bark of M. officinalis significantly reduced absorption and increased elimination of honokiol in vivo. It's worth noticing that the volume of distribution of lignan was quite lower than that of a glycoside. Moreover, the metabolic profiling of magnoloside A, honokiol, and magnolol in vivo was analyzed by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry method, from which three prototypes were identified and 35 metabolites were putatively characterized, and 18 unknown metabolites were reasonably characterized for the first time. The results indicated that sulfation and glucuronidation were the main metabolic pathways of honokiol and magnolol.

Peroxymonosulfate activation by bimetallic modified syderolite pellets catalyst for degradation of brominobenzonitrile

In this study, syderolite (Sd) pellets loaded with bimetallic oxides (Sd-Ni-Co) catalyst was prepared for the first time, which was used to activate peroxymonosulfate (PMS) for the degradation of Brominobenzonitrile (BMN). The effects of the Sd-Ni-Co dose, PMS dose, pH value, BMN concentration, and different anions on the degradation experiment were explored. The optimal reaction conditions for the degradation of 50 mg/L BMN were 100 g/L Sd-Ni-Co and 0.2 g/L of PMS, and the degradation was complete at room temperature within 40 min. The ten continuous cycle test shows the perfect structural stability of Sd-Ni-Co. Sd-Ni-Co/PMS system not only shows a good degradation performance on BMN but also on other organics, indicating that the method has a good universality. The radical quenching experiments (ethanol and tert-butanol) show that both •OH and SO4-·play an important role in this reaction system, and further confirmed the result by electron paramagnetic resonance (EPR) spectra. The Sd-Ni-Co was characterized by SEM, XRD, XPS, and BET. The degradation process was analyzed by triple quadrupole liquid chromatography-mass spectrometry (LC-MS), and the possible degradation pathway and mechanism were proposed.

Simultaneous quantification of multiple amino acid adducts from sulfur mustard-modified human serum albumin in plasma at trace exposure levels by ultra-high performance liquid chromatography–triple quadrupole mass spectrometry after propionyl derivatization

Sulfur mustard (HD) is a highly toxic vesicant and is prohibited by the Organisation for the Prohibition of Chemical Weapons (OPCW). HD can modify human serum albumin (HSA) to generate hydroxyethylthioethyl (HETE) adducts, which could be utilized as biomarkers for verifying HD exposure in forensic analysis. Here, five amino acid adducts generated from pronase digestion of HD-exposed human serum albumin (HD–HSA) in plasma were selected as biomarkers to retrospectively detect HD exposure. HD–HSA was precipitated from plasma with acetone, digested by pronase, derivatized with propionic anhydride (PA), and analysed with ultra-high performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC–TQ MS). The limits of detection (LODs) and limits of quantification (LOQs) of the HD exposure concentrations were evaluated as 1.00 ng/mL at S/N≥3 and 3.00 ng/mL at S/N≥10, respectively, which are approximately 60 times lower than those of the reported method. The approach shows good linearity (R2≥0.997) from 3.00 ng/mL to 10.0 µg/mL of HD-exposed human plasma with satisfactory precision and accuracy. The developed approach was applied to analysing samples from the 6th OPCW Biomedical Proficiency Test (BioPT). The study showed that the developed approach was also suitable for analysing human plasma samples that were exposed to six of HD analogues, which were common impurities in sulfur mustard mixtures. Moreover, the method was successfully applied to plasma from other species, including rabbits, rats and cattle. This study provides a reliable and sensitive tool for the retrospective detection of vesicants exposure based on multiple biomarkers.

Development of a Quantitative Method for Detection of Multiclass Veterinary Drugs in Feed Using Modified QuPPe Extraction and LC-MS/MS.

A method was developed for the rapid and quantitative analysis of 30 veterinary drugs belonging to 17 classes (amphenicols (1), anthelmintics (1), cephalosporins (4), coccidiostats (1), lincosamides (1), macrolide (1), nitroimidazole (1), penicillins (3), phenylhydrazines (1), polypeptides (1), pyrethrins (1), quinolones (5), sulfonamides (3), tetracycline (3), neuroleptic agents (1), triazene trypanocidal agents (1), other. (1)) in feeds. The proposed method with a modified Quick Polar Pesticides (QuPPe) sample preparation was validated for the determination of 30 veterinary drugs in feed samples by liquid chromatography triple-quadrupole mass spectrometry (LC–MS/MS). The sample was extracted with methanol containing 1% acetic acid and purified by dispersive solid-phase extraction (d-SPE) with C18. Good linearity (r2 ≥ 0.98) was observed, and the LOQ values ranged from 10 to 200 µg/kg. Average recoveries ranged from 70.8 to 118.4%, and the relative standard deviation was ≤ 18.7%. This validated method was used in the determination of 30 veterinary drugs in 142 feed samples obtained from South Korea. The results show that lincomycin was present in only one of the tested feed samples, although it was detected at a value lower than the LOQ. In conclusion, this multi-residue method can be used for screening through the detection and quantitation of residual multiclass veterinary drugs in feed samples.

Polyacylated Anthocyanins Derived from Red Radishes Protect Vascular Endothelial Cells Against Palmitic Acid-Induced Apoptosis via the p38 MAPK Pathway

Palmitic acid (PA), a widely consumed saturated fat, is known to induce the apoptosis of vascular endothelial cells. This study examined the protective effect of anthocyanin from red radish (ARR), which has been shown to protect the cardiovascular system and is rich in polyacylated pelargonidin (P) glycosides, on PA-treated SV 40 transfected aortic rat endothelial cells (SVAREC). In all, 22 distinct anthocyanins were identified in the ARR via ultra-high-performance liquid chromatography-triple quadrupole mass spectrometry, the most abundant of which were pelargonidin-3-(p-coumaroyl)diglucoside-5-glucoside (31.60%), pelargonidin-3-(feruloyl)diglucoside-5-(malonyl)glucoside (22.98%), pelargonidin-3-(p-coumaroyl)diglucoside-5-(malonyl)glucoside (8.02%), and pelargonidin-3-(feruloyl)diglucoside-5-glucoside (6.25%). P displayed the highest serum level (93.72%) in the ARR-treated mice, while polyacylated P glucosides were also absorbed intact. Furthermore, ARR treatment effectively increased cellular activity and reduced the ratio of Bcl-2-associated X protein : B cell lymphoma-2, while simultaneously alleviating the excessive production of reactive oxygen species in PA-treated SVAREC. Transcriptome and further verification analyses confirmed that the ARR-inhibiting PA-induced apoptosis of SVAREC was related to the p38 mitogen-activated protein kinase signaling pathway. Our results are the first to demonstrate that ARR may be a promising phytochemical in the prevention of PA-induced endothelial dysfunction.

Characterization of phenolic profile in dried grape skin of Vitis vinifera L. cv. Pinot Blanc with UHPLC-MS/MS and its development during ripening

Comprehensive phenolic composition of dried grape skin from cv. Pinot Blanc and its development during ripening is reported, with particular emphasis on flavonol glycosides profile. Extraction procedure and reversed-phase ultra-high-performance liquid chromatography-triple quadrupole mass spectrometry (UHPLC-QqQ-MS/MS) method were optimized and validated for the determination of 39 phenolic compounds belonging to different groups (flavonols, dihydroflavonols, benzoic and hydroxycinnamic acids, flavan-3-ols). Beside selected reaction monitoring (SRM) for analytes available as standards, flavonols and dihydroflavonols profile was furtherly explored performing precursor ion scan (PIS) with neutral loss (NL) for unavailable compounds. Quercetin-3-O-rutinoside occurred as major flavonol component, and rutinosides for kaempferol- and isorhamnetin- structures were also quantitable. Presence of different myricetin derivatives was unveiled, with myricetin-3-O-glucoside being quantifiable at all ripening time points. Besides high levels of astilbin, dihydroquercetins profile resulted highly complex. Moreover, ratio between caftaric and coutaric acid and between isomers of coutaric acid at harvest was uncommon if compared to other white cultivars.