Full Scan Mode Research Articles

A sensitive HPLC–MS method for simultaneous determination of thirteen components in rat plasma and its application to pharmacokinetic study of Tanreqing injection

A rapid, sensitive and selective method based on high-performance liquid chromatography coupled with Q-Exactive mass spectrometry was developed and validated for simultaneous quantification of thirteen components in rat plasma, including chlorogenic acid, 5-caffeoylquinic acid, 4-caffeoylquinic acid, luteoloside, isochlorogenic acid A, B and C, scutellarin, baicalin, wogonin, baicalein, phillyrin and forsythoside A. After precipitating proteins from the plasma samples with methanol, chromatographic separation of the thirteen components was achieved by using an XBridge™ C18 column (2.1mm×150mm, 5μm) with the mobile phase consisting of methanol and 0.1% formic acid in water at a flow rate of 0.3mL/min. High-resolution MS quantification was adopted with detection on a Q-Exactive mass spectrometer in full-scan mode, and the results were obtained using a mass extraction window of 10ppm at a mass resolution of 70, 000. All the calibration curves exhibited good linearity (r2>0.991) over the measured ranges. The lower limit of quantitation (LLOQ) was in the range of 1.05–8.13ng/mL. The intra- and inter-day precision (RSD) was less than 11.70% and the accuracy (RE) ranged from −5.58% to 12.29%. No significant matrix effect was observed and the extraction recoveries of all the analytes were more than 79.36%. The developed method was applied to a pharmacokinetic study of the thirteen ingredients in rats after intravenous administration of Tanreqing at three doses of 3, 6 and 12mL/kg. The results indicated that 8 of the 13 components, isochlorogenic acid A, B and C, chlorogenic acid, baicalin, wogonin, luteoloside and forsythoside A, had linear pharmacokinetic properties in the tested dosage range.

Adsorption of Phenol and Chlorophenol Mixtures on Silicalite-1 Determined by GC-MS Method

A method is presented in which gas chromatography coupled with mass spectrometry (GC-MS) allows quantitative simultaneous detection of mixtures of phenol (Ph), 2-chlorophenol (2-CPh), 3-cholorphenol (3-CPh), and 4-cholorophenol (4-CPh) in aqueous mixtures after being adsorbed on silicalita-1, utilizing selected-ion monitoring (SIM) and full-scan modes mass selective detection. GCMS with SIM at m/z = 64 and m/z = 128 showed good detection selectivity for mixtures of Ph, 2-CPh and 3-CPh (M1), and 2-CPh and 4-CPh (M2). Silicalita-1 was obtained from an amorphous organo-alumino-silicic gel from rice husk, an abundant and low cost agricultural waste residue that is readily available in large quantities. This product was used as a sorbent for solid phase extraction of organic analytes from aqueous solutions. The adsorption of the three chlorophenol isomers, ortho-, meta-, and para-, by silicalite-1 has been studied independently, showing that meta- and para-chlorophenol isomers are adsorbed more than ortho-chlorophenol. However the adsorption behavior of mixtures of these isomers was not reported. In this work, it was found that when the ortho-isomer is mixed either with meta or para-chlorophenol, considerable differences were observed in the adsorption process; in the studied mixture, the ortho-isomer was adsorbed more than the meta-and para-chlorophenol.

Multiresidue Method for the Rapid Determination of Pesticide Residues in Tea Using Ultra Performance Liquid Chromatography Orbitrap High Resolution Mass Spectrometry and In-Syringe Dispersive Solid Phase Extraction.

A method based on in-syringe dispersive solid phase extraction (IS-D-SPE) and ultra performance liquid chromatography Orbitrap high resolution mass spectrometry for the multiresidue analysis of 117 pesticides in tea was developed. Full scan mode was acquired over an m/z range of 100–800 with Orbitrap resolution at 70000, followed by full scan/dd-MS2 mode for confirmation. The identification criteria of retention time and mass accuracy tolerance was ±0.20 min and ±5.0 ppm, respectively. MS/MS fragment ions obtained dd-MS2 were necessary to identify the pesticides with the same molecular mass weight. The IS-D-SPE technique involved a mixture of 200 mg PSA, 100 mg C18, and 15 mg multiwalled carbon nanotubes for the cleanup of tea matrix. Good linearity (R2 > 0.99) for 117 pesticides was obtained. Satisfactory recoveries in the range of 70–120% were obtained for 105 pesticides, while intraday and interday precisions were below 20%. Limits of quantification were generally 10 μg kg–1. Finally, this method was employed to analyze 117 pesticides in 70 tea samples.

Estimation of clinical parameters of chronic kidney disease by exhaled breath full-scan mass spectrometry data and iterative PCA with intensity screening algorithm

Breath mass spectrometry is a useful tool for identifying important compounds associated with health. However, there have been few studies that have explored human exhaled breath by full-scan mass spectrometry as a non-invasive method for medical diagnosis, which may be attributed to the difficulties resulting from multicollinearity and small sample sizes relative to a large number of product ions. In this study, breath samples from 54 chronic kidney disease patients were analyzed by selected ion flow tube mass spectrometry in the full-scan mode. With the signal intensities of product ions, we developed a novel and robust algorithm, iterative PCA with intensity screening (IPS), to build linear models for estimating important clinical parameters of chronic kidney disease. It has been shown that IPS provided good estimations in cross-validated samples, and furthermore the identified product ions could have direct medical relevance to the disease. The study demonstrated the potential of quantitative breath analysis using mass spectrometry for medical diagnosis, and the importance of applying appropriate statistical tools to unveil the rich information in this type of data.

Efficient Detection of α-, β-, and γ-Hexabromocyclododecane Isomers and Their Hydroxylated Metabolites in Poultry Tissues Based on Dispersive Solid Phase Extraction Using an Enhanced Lipid-Removing Material Combined with UPLC-MS/MS

A simple, quick, and efficient method based on dispersive solid phase extraction combined with ultra-high-performance liquid chromatography tandem mass spectrometry has been constructed for the detection of α-, β-, and γ- hexabromocyclododecane isomer and their hydroxylated metabolites in poultry tissues. Four different samples including poultry muscle, heart, fat, and liver were extracted with acetonitrile and cleaned up through dispersive solid phased extraction using enhanced lipid-removing material or the combination of primary secondary amine +C18+Z-sep. By analysis with UPLC mass spectrometry in full scan mode, it was shown that more co-eluting interference was removed by the former material than by the latter in four matrices. For α-, β-, and γ-hexabromocyclododecane isomer in poultry tissues analyzed by constructed method, they were quantitated using internal standards and validated at the fortification levels of 1, 10, and 50 μg kg−1. Satisfied recoveries ranging in 80.2–99.6% were obtained for three isomers with relative standard deviation ranging in 3.1–13.7%. Good recoveries were also obtained for monohydroxyl-hexabromocyclododecane, dihydroxyl-hexabromocyclododecane, monohydroxyl-pentabromocyclododecene, and monohydroxyl-tetrabromocyclododecadiene in spiked poultry liver samples.

Differentiation of Furanocoumarin Isomers with Ratio of Relative Abundance of Characteristic Fragment Ions and Application in Angelicae dahuricae Radix

C-5-substituted and C-8-substituted furanocoumarin isomers, two important kinds of furanocoumarin, are widely documented as the main active constituents in Angelicae dahuricae radix. Due to the similar polarity and mass fragmentation pathways of such isomers, it is difficult to distinguish them using mass spectrometric methods. To address this issue, we developed a strategy employing combined full scan and product ion scan modes on an ultra high performance liquid chromatography–quadrupole time-of-flight tandem mass spectrometry (UHPLC-Q-TOF-MS) platform to differentiate four pairs of furanocoumarin isomer, viz. xanthotoxin and bergapten, imperatorin and isoimperatorin, psoralen and isopsoralen, and impinellin and isoimpinellin. A novel method using the ratio of relative abundance (RRA) of characteristic fragment ions was established to distinguish C-5-substituted and C-8-substituted furanocoumarin isomers, using the formula R = M/N, where M and N represent the ratios of relative abundance of characteristic fragment ions of a pair of furanocoumarin isomers. For R value greater than 1, compound M is substituted at C-5, whereas for R value less than 1, compound M is substituted at C-8. This method with good repeatability was applied to identify five pairs of isomeric furanocoumarins in Angelicae dahuricae radix. This is the first method to distinguish C-5-substituted and C-8-substituted furanocoumarin isomers, and can be used in complex matrix.

Non-targeted acquisition strategy for screening doping compounds based on GC-EI-hybrid quadrupole-Orbitrap mass spectrometry: A focus on exogenous anabolic steroids.

This is a first look at a non-targeted screening method based on Orbitrap gas chromatography-mass spectrometry (GC-MS) technology for a large number of banned compounds in sports found in urine, including exogenous anabolic steroids, β-agonists, narcotics, stimulants, hormone modulators, and diuretics. A simple sample preparation was processed in four steps: an enzymatic hydrolysis, liquid-liquid extraction, evaporation, and trimethylsilylation. All compounds were able to meet the World Anti-Doping Agency's sensitivity criteria with mass accuracies less than 1ppm and with sufficient points across the peak by running the Orbitrap GC-MS in full-scan mode. In addition, we discuss our initial findings of using a full-scan selected ion monitoring-tandem mass spectrometry (SIM-MS/MS) approach as a way to obtain lower detection limits and reach desirable selectivity for some exogenous anabolic steroids.

Development of a fast and cost-effective gas chromatography-mass spectrometry method for the quantification of short-chain and medium-chain fatty acids in human biofluids.

The quantification of short-chain and medium-chain fatty acids is becoming more and more relevant in fecal and plasma samples due to their biological impact, which has been associated with colon rectal cancer and fiber consumption. For these reasons, a fast, cost-effective, and reproducible analytical method is highly required. In this research, a gas chromatography-mass spectrometry method based on full scan and multiple reaction monitoring (MRM) acquisition modes were optimized and validated for the analysis of short-chain and medium-chain fatty acids in three biological samples: human fecal water, fecal fermentation supernatants, and human plasma. Several extraction solvents (acidified water, diethyl ether, dichloromethane, ethyl acetate, and methyl tert-butyl ether (MTBE) were further evaluated, demonstrating that the latter was clearly the most suitable solvent with recoveries from 75.4 to 124.4% and coefficient of variations lower than 20%. The applicability of the GC-MS method was tested, for instance, acetic acid was quantified by using samples of plasma and feces from healthy donors at mean values of 66.9μM and 24.5mM, respectively. The optimized protocol could successfully find applications within multi-compartment human studies. In parallel, a second pilot experiment on fecal fermentation supernatants indicated that the proposed protocol is suitable to follow the formation of SCFAs during in vitro fermentation by the human gut microbiota. In summary, the present work provided an improved GC-MS method for precise and accurate quantification of SCFAs and MCFAs in human feces and plasma.

Investigation of natural dyes in 15th c. documents seal threads from the Romanian Academy Library, by LC-DAD-MS (triple quadrupole)

Abstract Dyes and biological sources in 40 samples from red seal threads in 38 documents issued by the Chancery of Moldavia between 1460 and 1503 were investigated by liquid chromatography with UV-Vis (DAD) and mass spectrometric (MS) detection. Lac dye ( Kerria lacca Kerr), redwood type ( Caesalpinia spp.) and madder ( Rubia sp.), as individual dyes or in combinations, were responsible for the colour in all the dyed yarns while tannins were present in more than half of the total number of samples. The presence of major dyes, such as alizarin, purpurin, laccaic acid A and soluble redwood — a marker compound for Caesalpinia species were observed by both DAD and MS detectors while minor compounds (rubiadin, anthragallol, xanthopurpurin, munjistin, flavokermesic acid etc.) were only detected by mass spectrometry. Single stage MS detection was used in the Full Scan mode followed by data processing through Ion Extraction according to the molecular ions of compounds in the database. Tandem MS detection (MS 2 ) was also achieved, through using the Product Ion Scan operating mode. Identification of dyes was made according to retention time, UV-Vis and MS data, based on information collected on standards — dyes and dyed fibers. The biological sources detected are discussed as compared with those identified in ecclesiastical embroideries from the same period, ordered by the same Prince, Stephan the Great (1457–1504).

Design for the transfer of a validated liquid chromatography/tandem mass spectrometry analytical method for the determination of antimicrobial residues in honey from low-resolution to high-resolution mass spectrometry.

This paper investigates the validity of the transfer of a liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the determination of veterinary medicinal products in honey and compares it with an LC/linear ion trap/Orbitrap mass spectrometry method. A descriptive statistical approach was used in order to assess whether such a transfer would succeed or fail. This approach is based on the simultaneous evaluation of the trueness and of the intermediate precision for each compound at a 95% interval of confidence of both analytical techniques. Two grams of honey were placed in a centrifuge tube and diluted with 2.5mL of ultra-pure water and 2.5mL of acidified methanol with hydrochloric acid at 2mol.mL-1 . The extract was purified with 50mg of primary secondary amine and then analyzed using LC/MS/MS in multiple reaction monitoring (MRM) mode and LC/orbitrap high-resolution mass spectrometry in full scan mode. Both analytical techniques were compared by using the descriptive statistical approach for the determination of antimicrobial residues in honey. The transfer of the method showed that the Orbitrap system provides the same accurate analytical results compared with the LC/MS/MS method except for 4-epitetracycline, anhydroerythromycin A, erythromycin A enol ether, and dihydrostreptomycin. Furthermore, the LC/LTQ-Orbitrap system is capable of successfully competing with the LC/MS/MS method by additional provision of high mass resolution and mass accuracy even though it shows less sensitivity compared with the LC/MS/MS instrument. CCα levels for most analytes were 1.3 times higher by LC/MS/MS than those observed by LC/LTQ-Orbitrap. The method was assessed in terms of relative bias through analysis of a reference material provided by FAPAS (Food Analysis Performance and Assessment Scheme) and also through the control of several contaminated honey samples from local Lebanese markets. Satisfactory relative bias was below 22% except for tetracycline found in one sample that showed a higher bias at 29%. The LC/LTQ-Orbitrap method offers adequate performance in comparison with previously validated method on a LC/MS/MS system resulting in acceptance of the transfer of the method from LC/MS/MS to LC/LTQ-Orbitrap. Copyright © 2017 John Wiley & Sons, Ltd.

In vitro discrimination of wound-associated bacteria by volatile compound profiling using selected ion flow tube-mass spectrometry.

To determine if bacterial species responsible for clinically relevant wound infection produce specific volatile profiles that would allow their speciation. Selected ion flow tube-mass spectrometry (SIFT-MS) in full mass scan mode was used to analyse headspace gases produced by wound-associated bacteria grown invitro, so as to enable identification of bacterial volatile product ion profiles in the resulting mass spectra. Applying multivariate statistical analysis (hierarchical clustering and principal component analysis) to the resultant mass spectra enabled clear speciation. Moreover, bacterial volatile product ions could be detected from artificially contaminated wound dressing material, although the pattern of product ions detected was influenced by culture conditions. Using selected product ions from the SIFT-MS mass spectra it is possible to discriminate wound-associated bacterial species grown under specific invitro culture conditions. The results of this study have shown that wound-associated bacteria can be discriminated using volatile analysis invitro and that bacterial volatiles can be detected from wound dressing material. This indicates that volatile analysis of wounds or dressing material to identify infecting microbes has potential and warrants further study.

Analysis of Alkaline and Neutral Volatile Metabolites in Feces by Gas Chromatography-Tandem Mass Spectrometry

Abstract A rapid gas chromatography-tandem mass spectrometric (GC-MS) method was developed for the analysis of alkaline and neutral volatile metabolites of feces from human and rats. Feces were extracted by 75% methanol solution (V/V). After addition of ammonia solution (pH 10, final concentration of 1%), the supernatant was subjected to GC-MS analysis. The interesting compounds were separated on a CP-Sil 5 (25 m × 0.25 mm × 0.12 μm) capillary column. Helium was employed as a carrier gas at a constant flow rate of 1 mL min−1. Oven temperature was programmed as follows: the initial temperature was set at 50 °C and held for 1 min, then increased at 25 °C min−1 to 150 °C, sustained for 1 min; increased at 20 °C min−1 to 200 °C, held for 2 min; and finally increased at 10 °C min−1 to 270 °C, maintained for 5 min. The MS was operated in the electron impact ionization mode at −70 eV. The injector, ion source and transfer line temperatures were maintained at 220 °C, 230 °C and 280 °C, respectively. Mass data were acquired in full scan mode of m/z 10–600. The solvent delay time was set 3 min. A total of eleven volatile components were identified in the feces samples from human and seven in the feces samples from rats by retrieving the NIST library, comparing with the standards and analyzing the MS data. The method was simple and sensitive, and could be used to detect alkaline and neutral volatile metabolites of feces from human and rats.

Metabolic Profiling of Hoodia, Chamomile, Terminalia Species and Evaluation of Commercial Preparations Using Ultrahigh-Performance Liquid Chromatography Quadrupole-Time-of-Flight Mass Spectrometry.

Ultrahigh-performance liquid chromatography quadrupole-time-of-flight mass spectrometry (UHPLC-QToF-MS) profiling was used for the identification of marker compounds and generation of metabolic patterns that could be interrogated using chemometric modeling software. UHPLC-QToF-MS was used to generate comprehensive fingerprints of three botanicals (Hoodia, Terminalia, and chamomile), each having different classes of compounds. Detection of a broad range of ions was carried out in full scan mode in both positive and negative modes over the range m/z 100-1700 using high-resolution mass spectrometry. Multivariate statistical analysis was used to extract relevant chemical information from the data to easily differentiate between Terminalia species, chamomile varieties, and quality control of Hoodia products. Using nontargeted analysis, identification of 37 compounds contributed to the differences between Terminalia species, 26 flavonoids were identified to show the differences between German and Roman chamomile, and 43 pregnane glycosides were identified from Hoodia gordonii samples. The UHPLC-QToF-MS-based chemical fingerprinting with principal component analysis was able to correctly distinguish botanicals and their commercial products. This work can be used as a basis to assure the quality of botanicals and commercial products.

A new method for macrolide antibiotics determination in wastewater from three different wastewater treatment plants

Abstract An effective and practical method for the determination of macrolide antibiotics azithromycin, clarithromycin, erythromycin and roxithromycin in wastewater samples has been developed. The analytical method combines solid phase extraction followed by a chromatographic separation by hydrophilic interaction liquid chromatography (HILIC) coupled with an ion trap mass spectrometer utilizing the electrospray ionization technique. Detection of positively charged ions was performed in full scan mode from 500 to 900 m/z. The method detection limits and method quantification limits obtained were in the range of 2.03-7.59 ng L-1 and 6.08-23.84 ng L-1, respectively. Recoveries of solid phase extraction were obtained using SupelTM-Select HLB cartridges ranging from 85.76 % to 92.54 %. All target antibiotics were detected in 100 % of the collected raw influent samples with concentrations varying from 15 ng L-1 to 1849 ng L-1. Azithromycin, clarithromycin and erythromycin were also detected in 100 % of the treated water samples and roxithromycin was present in 96 % of the samples. The highest determined concentration in the treated water samples was 1404 ng L-1 of azithromycin. Based on the determined macrolide concentrations, removal efficiencies of individual wastewater treatment plants were calculated to range from 13 % to 100 %.

Novel sulphur-containing imatinib metabolites found by untargeted LC-HRMS analysis

Untargeted metabolite profiling using high-resolution mass spectrometry coupled with liquid chromatography (LC-HRMS), followed by data analysis with the Compound Discoverer 2.0™ software, was used to study the metabolism of imatinib in humans with chronic myeloid leukemia. Plasma samples from control (drug-free) and patient (treated with imatinib) groups were analyzed in full-scan mode and the unknown ions occurring only in the patient group were then, as potential imatinib metabolites, subjected to multi-stage fragmentation in order to elucidate their structure. The application of an untargeted approach, as described in this study, enabled the detection of 24 novel structurally unexpected metabolites. Several sulphur-containing compounds, probably originating after the reaction of reactive intermediates of imatinib with endogenous glutathione, were found and annotated as cysteine and cystine adducts. In the proposed mechanism, the cysteine adducts were formed after the rearrangement of piperazine moiety to imidazoline. On the contrary, in vivo S-N exchange occurred in the case of the cystine adducts. In addition, N-O exchange was observed in the collision cell in the course of the fragmentation of the cystine adducts. The presence of sulphur in the cysteine and cystine conjugates was proved by means of ultra-high resolution measurements using Orbitrap Elite. The detection of metabolites derived from glutathione might improve knowledge about the disposition of imatinib towards bioactivation and help to improve understanding of the mechanism of its hepatotoxicity or nephrotoxicity in humans.

High-throughput screening for drugs of abuse and pharmaceutical drugs in hair by liquid-chromatography-high resolution mass spectrometry (LC-HRMS)

A liquid chromatography–high resolution mass spectrometry (LC-HRMS) method for the simultaneous screening in hair samples of drugs of abuse and medicaments was developed. Target analytes screened using a single extraction and analytical run were opiates, cocaine, amphetamines and amphetamine-like substances, ketamine and analogues, cannabinoids, both natural and synthetic, cathinones, piperazines, ephedrines and others new psychoactive substances not pertaining to these classes; pharmaceutical drugs such as antipsychotics, antiepileptics, antidepressants, benzodiazepines and analogues, anorectics, stimulants, drugs for the erectile dysfunction.The multiresidual method involved methanolic incubation of 30mg of decontaminated hair and analysis of the extract in HPLC using a C18 column. The mass detector, a benchtop Orbitrap Exactive, with nominal resolving power of 100,000, operated in full scan mode in positive ESI. Analytes were identified by exact mass, correspondence of isotopic cluster and retention times using a home-made database. The database contained the protonated exact masses of each monoisotopic compound, the retention time and the molecular formula of each studied analyte. At the moment the database contains 177 analytes. The screening method was validated for selectivity, limit of detection (LOD), matrix effect and carryover. The limits of detection obtained varied from 2 to 30pg/mg, and the matrix effect was negligible.This method was then applied to three hundred authentic samples, resulting in the identification of various drugs of abuse and therapeutic drugs. The analyte identity was subsequently confirmed by in-source fragmentation. Thanks to the scan acquisition, this method also enables retrospective re-analysis of the acquired datafile in case a further analyte needs to be screened.

Distribution of trans-resveratrol and its metabolites after acute or sustained administration in mouse heart, brain, and liver.

Trans-resveratrol is widely studied for its potentially beneficial effects on numerous disorders. It is rapidly metabolized and its metabolites can exhibit biological activity. The present study aimed to investigate whether acute or sustained trans-resveratrol administration impacted on the distribution of trans-resveratrol and its metabolites in brain, heart, and liver. We used ultra-HPLC quadrupole-TOF (UHPLC-Q-TOF) in a full-scan mode to identify and assess large numbers of resveratrol metabolites. For acute intake, mice were overfed with a single dose of trans-resveratrol (150 mg/kg) and organs were collected after 30 and 60 min. For sustained intake, trans-resveratrol was given in the chow (0.04% w/w corresponding to 40 mg/kg/day), and plasma and the organs were collected after 3 months of this resveratrol diet. We found that trans-resveratrol-3-O-glucuronide and resveratrol-3-sulfate were the main metabolites found after acute intake, and free trans-resveratrol (in the brain and heart) and dihydroresveratrol derivatives were found after sustained administration CONCLUSIONS: Our results show notable differences between acute and sustained administration of trans-resveratrol and distribution of trans-resveratrol and its metabolites in mouse heart, brain, and liver. The results suggest a strategy for development of galenic forms of resveratrol.

Liquid chromatography-high resolution-tandem mass spectrometry using Orbitrap technology for comprehensive screening to detect drugs and their metabolites in blood plasma

Orbitrap technology was successfully applied for broad metabolite-based LC-high resolution (HR)-MS screening of drugs in clinical and forensic toxicology. This paper aims to elucidate whether this technology can also be used for a corresponding blood plasma screening after simple precipitation without or with consecutive on-line extraction using turbulent flow chromatography (TurboFlow). The analytes were separated within 10 min and detected by a Q-Exactive mass spectrometer in full scan mode after positive/negative switching. In one single run, a target screening for about 700 relevant compounds was developed in parallel with data-dependent acquisition for unknowns. A compound was positively identified when the corresponding accurate mass precursor ion and the five most intense fragment ions were detected and the MS/MS spectrum fits well with the corresponding full HR-MS/MS reference library currently containing over 2000 parent drugs and 2500 metabolites. All over all run times were 17 min for precipitation and 21 min for TurboFlow after precipitation. Method validation was successfully performed for representative drugs and metabolites concerning recovery, matrix effect, process efficiency, and limits of detection and identification. Process efficiency data ranged for most analytes from 3 to 138% with coefficients of variation (CV) ≤ 20% for precipitation and from 1 to 156% with CV ≤ 20% for TurboFlow. Applicability studies showed that the developed method provided fast, simple, and robust screening and identification of a broad range of drugs within therapeutic ranges.

Effect of alprazolam on rat serum metabolic profiles.

We developed a serum metabolomic method by gas chromatography-mass spectrometry (GC-MS) to evaluate the effect of alprazolam in rats. The GC-MS with HP-5MS (0.25 μm × 30 m × 0.25 mm) mass was conducted in electron impact ionization (EI) mode with electron energy of 70 eV, and full-scan mode with m/z 50-550. The rats were randomly divided to four groups, three alprazolam-treated groups and a control group. The alprazolam-treated rats were given 5, 10 or 20 mg/kg (low, medium, high) of alprazolam by intragastric administration each day for 14 days. The serum samples were corrected on the seventh and fourteenth days for metabolomic study. The blood was collected for biochemical tests. Then liver and brain were rapidly isolated and immersed for pathological study. Compared with the control group, on the seventh and fourteen days, the levels of d-glucose, 9,12-octadecadienoic acid, butanoic acid, l-proline, d-mannose and malic acid had changed, indicating that alprazolam induced energy metabolism, fatty acid metabolism and amino acid metabolism perturbations in rats. There was no significant difference for alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, urea and uric acid between controls and alprazolam groups. According to the pathological results, alprazolam is not hepatotoxic. Metabolomics could distinguish different alprazolam doses in rats.

Tentative Characterization of Polyphenolic Compounds in the Male Flowers of Phoenix dactylifera by Liquid Chromatography Coupled with Mass Spectrometry and DFT.

Phoenix dacylifera is an ancient palm species rich in (poly)phenols. These phenolic compounds were tentatively identified by using liquid chromatography coupled with ion spray mass spectrometry in tandem mode (LC/MS/MS) with negative ion detection. Negative identification of the compounds was based on their retention times and mass spectra in full scan mode (MS), and in different MS/MS modes. For the first time, complete hypothesis, and routs for both p-coumaroylshikimic acids (CoSA) and caffeoylshikimic acids (CSA) were suggested and confirmed by Density Fonctional Theory (DFT) study. Notably, of the 53 compounds characterized, 19 hydroxycinnamates derivatives were tentativelycharacterized in male flowers of date palm and 15 of them were recorded for the first time. In addition, five organic acids, six B-type proanthocyanidins, two anthocyanidin and 21 flavonoid derivatives have been tentatively characterized. Identification of B-type proanthocyanidins were based on the diagnostic ions resulting from heterocyclic ring fission (HRF) and retro-Diels-Alder (RDA) reaction of flavan-3-ol provided information on the hydroxylation pattern and the type of inter-flavan bond proanthocyanidins. The sequence of proanthocyanidins was detected through ions extracted from quinone methide (QM) cleavage of the inter-flavan bond.