Performance Liquid Chromatography-ion Trap Research Articles

Pharmacokinetics and distribution of cathine and cathinone in rats

Khat is a stimulant plant that contains stimulant chemicals such as cathine and cathinone, which abuses to induce euphoria, alertness, and motor activity. This study was carried out to determine the pharmacokinetic and distributions of cathine and cathinone following a single dosage of khat extract in rats. Practically, a total of 24 adult male Wistar albino rats aged between 8 and 12 weeks (250‐300 g weight) were randomly selected and divided into six groups 4 rats each. After a single dosage (2000 mg/kg body weight) administered by oral gavage, each group was sacrifice at specific time that schedules to be 0.5, 1, 2.5, 5, 12, and 24 hours for group number 1, 2, 3, 4, 5, and 6, respectively. Specimens were obtained as tissues and separated serum for consequences analysis. The mass spectra profiles of the interested analytes were detected by using two different types of liquid chromatography mass spectrometry; (i) Ultra‐performance liquid chromatography in coupled with with quadrupole time‐of‐flight mass spectrometry (UPLC‐QTOF/MS) system, (ii) High performance liquid chromatography ion trap mass spectrometry (HPLC‐IT/MS) system. Cathine and cathinone were qualified and quantified in serum, brain, lung, heart, liver and kidney following a single khat administration dosage. The highest tissue levels were reach within 0.5 hour in the lung, liver, and heart for cathine and within 0.5 hour in the heart for cathinone. Interestingly, more than 60% of the serum content of cathine and cathinone reached the peak in the brain within 2.5 hours with mean residence time (MRT last) 2.31 – 3.31 hours. Moreover, at the level of the neurotransmitters such as epinephrine, dopamine, norepinephrine and serotonin, their presence were detected in a delayed, prolonged and organ specific manner. This findings provided further basis for experimental, clinical, and forensic studies.

Tapping into the realm of underutilised green leafy vegetables: Using LC-IT-Tof-MS based methods to explore phytochemical richness of Sonchus oleraceus (L.) L.

Sonchus oleraceus (L.) L. (sow thistle) is an underutilised functional leafy vegetable with both high nutritional and pharmacological values. In the current study, high performance liquid chromatography ion trap time-of flight mass spectrometry (HPLC-IT-Tof-MS)-based metabolomics in combination with principal component analysis (PCA) were used to provide an overall phytochemical composition of different tissues (leaf, stem and roots) of this underutilised plant. A total of 32 phytochemicals, comprising hydroxycinnamic acids, flavonoids and terpene classes were identified across the three different tissues of S. oleraceus. The study used the new approach of colour coded PCA models to info-graphically depict the metabolic profiles across different parts of the plant. The results of the current study indicate S. oleraceus as a potential source of metabolites with highly claimed nutraceutical properties. As such, the results herein can be used as a template reference for further biological studies aimed at the evaluation of nutraceutical properties of the S. oleraceus plant.

Yew (Taxus) intoxication in free-ranging cervids.

Wild ruminants, including deer species (cervids) have incorrectly been regarded as refractory to yew (Taxus) intoxication. This assumption has been based upon anecdotal observations of individual deer browsing on yew over time without apparent adverse effect. A single case of yew intoxication was reported in a free-ranging Norwegian moose (Alces alces) in 2008. The current report describes five additional cases of yew toxicosis in moose, seven in roe deer (Capreolus capreolus) and two in reindeer (Rangifer tarandus tarandus), all in Norway. The animals were found dead during the winter, close to or within gardens containing yew plants showing signs of browsing. Gross findings included lung congestion and edema, thoracic and pericardial effusion, bilateral heart dilatation, epi- and endocardial hemorrhage, and enlarged (congested) spleen. Yew plant remnants were detected in the rumen of all animals with the exception of a single moose. Histology revealed multifocal acute myocardial degeneration and necrosis with hemorrhage in roe deer, but not in the two other species. A qualitative high performance liquid chromatography–ion trap mass spectrometry analysis was used to tentatively identify five major Taxus alkaloids (taxines) in crude yew extracts and in heart and liver samples from the moose cases. All five major taxines were detected with good signal/noise ratio in tissue samples from the four moose with visible ruminal yew content, whereas lower levels of taxines were detected in the moose without visible ruminal yew content. Possible differences in interspecies tolerance to taxines and role of individual protective adaptation are discussed.

Qualitative Identification of Fentanyl Analogs and Other Opioids in Postmortem Cases by UHPLC-Ion Trap-MSn.

Since 2013, the Miami-Dade County Medical Examiner Department has experienced an increase in the number of opioid-related deaths. The majority of cases coincided with the introduction of fentanyl into the local heroin supply. From 2014 to 2015, Miami-Dade County experienced a near 600% increase in fentanyl-related deaths, followed by an additional 200% increase in 2016. In 2015, two novel fentanyl analogs were identified in medical examiner cases: beta-hydroxythiofentanyl and acetyl fentanyl. In 2016, four additional fentanyl analogs emerged: para-fluoroisobutyryl fentanyl, butyryl fentanyl, furanyl fentanyl and carfentanil, as well as the synthetic opioid U-47700. In order to address this epidemic, a method was developed and validated to identify 44 opioid-related and analgesic compounds in postmortem samples using ultra high performance liquid chromatography ion trap mass spectrometry with MSn capabilities. The limit of detection for all compounds ranged from 0.1 to 5 ng/mL, with a majority having MS3 spectral fragmentation. Blood, urine, liver or brain specimens from ~500 postmortem cases were submitted for analysis based on case history and/or initial screening results. Of those cases, 375 were positive for illicit fentanyl and/or one or more fentanyl analogs. Due to the potency of these compounds, they were almost always included in the cause of death. Worth emphasizing and extremely alarming is the detection of carfentanil in 134 cases, 104 of which were initially missed by gas chromatography mass spectrometry. By incorporating this sensitive, highly specific, and evolving screening procedure into the workflow, the toxicology laboratory continues to effectively assist the medical examiners in determining the cause and manner of death of decedents in Miami-Dade County.

Aerobic Biodegradation of 2-Picolinic Acid by a Comamonas sp.

A strain was able to use 2-picolinic acid (2-PA) as a sole source of carbon, nitrogen and energy under aerobic conditions was isolated in this paper. Based on 16S rRNA gene sequence analysis, this strain was identified as Comamonas sp. and named as ZD3. The effects of pH and initial concentrations of 2-PA on the degrading capacity of ZD3 were investigated. It was found that ZD3 degraded 2-PA effectively under a pH range of 5.0 to 9.0, in which 7.0 was proved to be the optimal value. When the initial concentration of 2-PA was 100, 200, 400, 600 and 800 mg/L, ZD3 completely degraded 2-PA within 10, 18, 22, 78 and 114 h, respectively. Zero order kinetic model expressed the degradation behavior of 2-PA by ZD3 well. It was observed that under the concentration range of 100 to 400 mg/L, the degradation rate constant increased with the increase in concentration and reached the maximum at 400 mg/L. However, under the concentration range of 600 to 800 mg/L, the degradation rate constant began to decrease, indicating an inhibitory effect. Moreover, ultraviolet scanning and high performance liquid chromatography ion trap timeof- flight mass spectrometry showed that during the degradation of 2-PA the first reaction was α hydroxylation so that 6-hydroxy picolinic acid (6-HPA) was produced.

The simultaneous determination of vitamins A, E and β-carotene in bovine milk by high performance liquid chromatography–ion trap mass spectrometry (HPLC–MSn)

Bovine milk is considered to be a good dietary source of vitamins A, E and β-carotene. This paper describes a robust method for the simultaneous determination of these compounds using high performance liquid chromatography–ion trap mass spectrometry (HPLC–MSn) as the determinative step. The compounds were separated with a 5 μm Polaris 2.1 × 150 mm C18-A column and an aqueous-methanol mobile phase and the levels determined using the MS2 fragments (vitamin A, m/z 213 and m/z 199, vitamin E m/z 165 and β-carotene m/z 413). The HPLC–MSn was operated in the positive ion APCI mode. The method was validated using repeatability studies, duplicate analyses, recovery experiments, proficiency study data and comparison with previously validated high performance liquid chromatographic ultraviolet/visible (HPLC–UV/Vis) and fluorescence (HPLC–Fl) procedures used in our laboratory. Expanded measurement uncertainties were similar for HPLC–MSn, HPLC–UV/Vis and HPLC–Fl, e.g. vitamin A 45 μg/100 ml, HPLC–MSn ±8%, HPLC–UV ±9%; vitamin E 150 μg/100 ml, HPLC–MSn ±11%, HPLC–Fl ±9%; β-carotene 12 μg/100 ml, HPLC–MSn ±18%, HPLC–Vis ±21%.

LC–MS characterization of metoclopramide photolysis products

The aim of this study was to investigate the photodegradation of the antiemetic drug metoclopramide. Metoclopramide aqueous solutions were photoirradiated at 254 nm under argon atmosphere. Irradiated metoclopramide solutions were analyzed by high performance liquid chromatography–ion trap mass spectrometry in order to characterize photolysis products. Rapid decrease in metoclopramide purity, following first-order kinetic, was observed following irradiation. The structures of 18 photolysis products were tentatively identified based on their mass spectra and fragmentation. The main degradation mechanism was scission of the chlorine which could be followed by polymerization of the resulting products since dimeric and trimeric products were observed.

Identification and characterization of supercritical fluid extracts of Rhizoma Chuanxiong by high performance liquid chromatography ion trap mass spectrometry

The main constituents, senkyunolide A, Z-ligustilide, neocnidilide, 3-butylphthalide, and ligustilide dimers, in supercritical CO2 fluid extracts of Rhizoma Chuanxiong, a popular Chinese traditional medicine, have been identified and characterized by high performance liquid chromatography tandem mass spectrometry. Separations were carried out on an Agilent (ECLIPSE XDB) C18 analytical column by gradient elution with 0.25% acetic acid and methanol (containing 0.25% acetic acid). An Agilent 1100 series LC/MSD XCT system was operated under positive ESI and auto MS/MS modes for mass spectrometric analysis. Collision-induced dissociation (CID) fragmentations of these phthalides have been investigated and elucidated. Phthalides have primarily undergone two ESI CID pathways: side-chain cleavage with losses of alkenes and ring-opening with eliminations of H2O followed by losses of CO. Direct neutral loss of CO has not been observed. Sodium adduct ions have demonstrated completely different CID pathways.

Pharmacokinetics and metabolism of 3,4-dichlorophenyl-propenoyl-sec.-butylamine in rats by high performance liquid chromatography–ion trap mass spectrometry

The pharmacokinetics (PK) and metabolism of 3,4-dichlorophenyl-propenoyl-sec.-butylamine (3,4-DCPB), a novel antiepileptic drug, were investigated after its oral administration to rats (100 mg/kg) by HPLC. The absorption and elimination of 3,4-DCPB were rapid. 3,4-DCPB was found to undergo extensive metabolism as the major route of elimination. Structures of the metabolites present in rat plasma were identified with liquid chromatography–electrospray ionization-mass spectrometry (LC–ESI-MS/MS). It was concluded that 3,4-DCPB was involved in the multiple metabolic pathways (hydrolysis, dealkylation and oxidation) and the hydrolysis product, 3,4-dichloro-cinnamic acid (M1) appeared to be the major metabolite.

Direct-injection high performance liquid chromatography ion trap mass spectrometry for the quantitative determination of olanzapine, clozapine and N-desmethylclozapine in human plasma.

A specific and sensitive direct-injection high performance liquid chromatography electrospray ionization tandem mass spectrometry (HPLC/ESI-MS/MS) method has been developed for the rapid identification and quantitative determination of olanzapine, clozapine, and N-desmethylclozapine in human plasma. After the addition of the internal standard dibenzepin and dilution with 0.1% formic acid, plasma samples were injected into the LC/MS/MS system. Proteins and other large biomolecules were removed during an online sample cleanup using an extraction column (1 x 50 mm i.d., 30 microm) with a 100% aqueous mobile phase at a flow rate of 4 mL/min. The extraction column was subsequently brought inline with the analytical column by automatic valve switching. Analytes were separated on a 5 microm Symmetry C18 (Waters) analytical column (3.0 x 150 mm) with a mobile phase of acetonitrile/0.1% formic acid (20:80, v/v) at a flow rate of 0.5 mL/min. The total analysis time was 6 min per sample. The inter- and intra-assay coefficients of variation for all compounds were <11%. By eliminating the need for extensive sample preparation, the proposed method offers very large savings in total analysis time.