Quantification of cortisol and its metabolites in human urine by LC-MSn: applications in clinical diagnosis and anti-doping control.

The objective of the current research was to develop a liquid chromatography-MSn (LC-MSn) methodology for the determination of free cortisol and its 15 endogenous metabolites (6ß-hydroxycortisol, 20α-dihydrocortisol, 20α-dihydrocortisone, 20-ß-dihydrocortisol, 20ß-dihydrocortisone, prednisolone, cortisone, α-cortolone, ß-cortolone, allotetrahydrocortisol, 5α-dihydrocortisol, tetrahydrocortisol, allotetrahydrocortisone, 5ß-dihydrocortisol, tetrahydrocortisone) in human urine. Due to its optimal performance, a linear ion trap operating in ESI negative ion mode was chosen for the spectrometric analysis, performing MS3 and MS4 experiments. The method was validated for limit of detection (LOD) and limit of quantification (LOQ) (0.01 ng mL-1 and 0.05 ng mL-1, for all compounds, respectively), intra- and inter-day precision (CV = 1.4-9.2% and CV = 3.6-10.4%, respectively), intra- and inter-day accuracy (95-110%), extraction recovery (65-95%), linearity (R2 > 0.995), and matrix effect that was absent for all molecules. Additionally, for each compound, the percentage of glucuronated conjugates was estimated. The method was successfully applied to the urine (2 mL) of 50 healthy subjects (25 males, 25 females). It was also successfully employed on urine samples of two patients with Cushing syndrome and one with Addison's disease. This analytical approach could be more appropriate than commonly used determination of urinary free cortisol collected in 24-h urine. The possibility of considering the differences and relationship between cortisol and its metabolites allows analytical problems related to quantitative analysis of cortisol alone to be overcome. Furthermore, the developed method has been demonstrated as efficient for antidoping control regarding the potential abuse of corticosteroids, which could interfere with the cortisol metabolism, due to negative feedback on the hypothalamus-hypophysis-adrenal axis. Lastly, this method was found to be suitable for the follow-up of prednisolone that was particularly important considering its pseudo-endogenous origin and correlation with cortisol metabolism.

Target profiling of flavonol glycosides in the extract of Ginkgo biloba leaf and their pharmacokinetics in rat plasma by ultra-high-performance liquid chromatography with tandem mass spectrometry.

The extract of Ginkgo biloba leaf is a popular herbal product or dietary supplement in the world to treat various diseases, and flavonol glycosides are considered as the main bioactive constituents. In this study, 37 flavonol glycosides were rapidly screened out by precursor ion scanning in positive ion mode with production ions at m/z 287.05, 303.05, and 317.06. Subsequently, a reliable and sensitive ultra-high-performance liquid chromatography coupled with triple quadrupole-linear ion trap mass spectrometry approach was established and validated to quantify the 20 prototype flavonol glycosides in rat plasma. Calibration curves showed good linearity (R2 ≥ 0.9894) over the corresponding concentration range. The precision, accuracy, extraction recovery, matrix effect, and stability were also satisfactory. The validated method was successfully applied to a pharmacokinetic study of prototype flavonol glycosides in rat after oral administration of the extract of G. biloba leaf. As a result, the Tmax of flavonol glycosides was short at 0.11-0.60 h. Quercetin-3-O-(2",6″-di-O-rhamnosyl)-glucoside, kaempferol-3-O-(2'',6''-di-O-rhamnosyl)-glucoside, quercetin-3-O-rutinoside, quercetin- 3-O-glucosyl-(1-2)-O-rhamnoside, and kaempferol-3-O-glucoside presented relatively high systemic exposure levels with AUC0-∞  > 500 µg h/L and Cmax  > 100 µg/L. This study would provide the valuable information for further scientific research and clinical application of the extract of G. biloba leaf.

[Determination of lipophilic marine biotoxins in shellfish foods by ultra performance liquid chromatography-hybrid triple quadrupole linear ion trap-mass spectrometry].

OBJECTIVE: An ultra performance liquid chromatography-hybrid triple quadrupole linear ion trap-mass spectrometry(UPLC-QqLIT-MS) was established for determination of lipophilic marine biotoxins in shellfish. And the 12 lipophilic marine biotoxins in shellfish were surveyed. METHODS: The lipophilic marine biotoxins in homogenized shellfish were ultrasonically extracted by methanol in super-sonic instrument, and cleaned up by solid phase extraction of Strata-X column, and eluted with methanol(containing 0.3% ammonia water). The elution was diluted with water, and cleaned by 0.22 µm millipore filter. The filtrate was separated on a Waters ACQUITY UPLC BEH C_(18) column(150 mm×2.1 mm, 1.7 µm)by gradient elution in 12 minutes with acetronitrile-water(containing 0.01%(V/V) ammonia and 2 mmol/L ammonium formate) as mobile phase, and detected by ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS), identified by electrospray ionization(ESI) in simultaneous scanning mode of positive and negative ions using multiple reaction monitoring, and quantified with external standards. Information dependent acquisition scan function(IDA) combined with enhanced production scan(EPI) was used to confirm the 12 lipophilic marine biotoxins. RESULTS: The calibration curves of 12 lipophilic marine biotoxins showed good linearity in the range of 0.5-50 µg/L with correlation coefficients were 0.9984-0.9999.The detection limits of the method were 0.15-0.29 µg/kg. The recoveries of three spiking levels ranged from 80.0% to 116.0%, and the relative standard deviation(RSD) were 0.6%-6.4%(n=7). CONCLUSION: The method for determination of 12 lipophilic marine biotoxins in shellfish by UPLC-QqLIT-MS was of operation convenience, less interference from impurities and good accuracy, which could meet the requirements for the determination of 12 lipophilic marine biotoxins residues in sea foods.

Use of phenyl/tetrazolyl-functionalized magnetic microspheres and stable isotope labeled internal standards for significant reduction of matrix effect in determination of nine fluoroquinolones by liquid chromatography-quadrupole linear ion trap mass spectrometry.

In this study, the strategy of unique adsorbent combined with isotope labeled internal standards was used to significantly reduce the matrix effect for the enrichment and analysis of nine fluoroquinolones in a complex sample by liquid chromatography coupled to quadrupole linear ion trap mass spectrometry (LC-QqQLIT-MS/MS). The adsorbent was prepared conveniently by functionalizing Fe3O4@SiO2 microspheres with phenyl and tetrazolyl groups, which could adsorb fluoroquinolones selectively via hydrophobic, electrostatic, and π-π interactions. The established magnetic solid-phase extraction (MSPE) method as well as using stable isotope labeled internal standards in the next MS/MS detection was able to reduce the matrix effect significantly. In the process of LC-QqQLIT-MS/MS analysis, the precursor and product ions of the analytes were monitored quantitatively and qualitatively on a QTrap system equipped simultaneously with the multiple reaction monitoring (MRM) and enhanced product ion (EPI) scan. Subsequently, the enrichment method combined with LC-QqQLIT-MS/MS demonstrated good analytical features in terms of linearity (7.5-100.0 ng mL-1, r > 0.9960), satisfactory recoveries (88.6%-118.3%) with RSDs < 12.0%, LODs = 0.5 µg kg-1 and LOQs = 1.5 µg kg-1 for all tested analytes. Finally, the developed MSPE-LC-QqQLIT-MS/MS method had been successfully applied to real pork samples for food-safety risk monitoring in Ningxia Province, China. Graphical abstract Mechanism of reducing matrix effect through the as-prepared adsorbent.

Mushroom poisoning of Panaeolus subbalteatus from Ningxia, northwest China, with species identification and tryptamine detection.

Mushroom poisoning is a significant contributor to foodborne disease outbreaks in China. This study focuses on two Panaeolus subbalteatus poisoning incidents accompanied by epidemiological investigations, species identification, and toxin detection in Ningxia, northwest China. In these two poisoning incidents, some patients exhibited gastrointestinal or neurological symptoms approximately 0.5 h after ingestion of a large amount of wild mushroom. Specifically, in Case 1, one of the three patients experienced nausea, vomiting, and numbness in the throat and limbs; in Case 2, one patient reported dizziness and an abnormal sense of direction. Through morphological and phylogenetic analyses, mushroom specimens were identified as P. subbalteatus. Psilocybin and psilocin were detected in mushroom samples, and only psilocin was detected in biological samples by liquid chromatography-triple quadrupole-linear ion trap mass spectrometry screening. The average psilocybin and psilocin contents in mushroom samples were 1532.2-1760.7 and 114.5-136.0 mg/kg (n = 3), respectively. Moreover, only psilocin was detected in blood and urine samples, with average concentrations 0.5-1.2 ng/mL (n = 3) and 2.5-3.1 ng/mL (n = 3), respectively. These findings provide technical support for managing similar incidents in the future.

Pseudotargeted Metabolomics Approach Enabling the Classification-Induced Ginsenoside Characterization and Differentiation of Ginseng and Its Compound Formulation Products.

The use of diversified ginseng extracts in health-promoting foods is difficult to differentiate, as they share bioactive ginsenosides among different Panax species (e.g., P. ginseng, P. quinquefolius, P. notoginseng, and P. japonicus) and different parts (e.g., root, leaf, and flower). This work was designed to develop a pseudo-targeted metabolomics approach to discover ginsenoside markers facilitating the precise authentication of ginseng and its use in compound formulation products (CFPs). Versatile mass spectrometry experiments on the QTrap mass spectrometer achieved classified characterization of the neutral, malonyl, and oleanolic acid-type ginsenosides, with 567 components characterized. A pseudo-targeted metabolomics approach by multiple reaction monitoring (MRM) of 262 ion pairs could assist to establish key identification points for 12 ginseng species. The simultaneous detection of 14 markers enabled the identification of ginseng from 15 ginseng-containing CFPs. The pseudo-targeted metabolomics strategy enabled better performance in differentiating among multiple ginseng, compared with the full-scan high-resolution mass spectrometry approach.

Characterization of Mycobacterium tuberculosis Mycolic Acids by Multiple-Stage Linear Ion-Trap Mass Spectrometry.

Mycobacterium tuberculosis (Mtb) cells are known to synthesize very long chain (C60-90) structurally complex mycolic acids with various functional groups. In this study, we applied linear ion-trap (LIT) multiple-stage mass spectrometry (MSn), combined with high-resolution mass spectrometry to study the mechanisms underlying the fragmentation processes of mycolic acid standards desorbed as lithiated adduct ions by ESI. This is followed by structural characterization of a Mtb mycolic acid family (Bovine strain). Using the insight fragmentation processes gained from the study, we are able to achieve a near complete characterization of the whole mycolic acid family, revealing the identity of the α-alkyl chain, the location of the functional groups including methyl, methoxy, and keto groups along the meroaldehyde chain in each lipid species. This study showcased the power of LIT MSn toward structural determination of complex lipids in a mixture, which would be otherwise very difficult to define using other analytical techniques.

[Simultaneous determination of 36 hypotensive drugs in fingerprints by ultra performance liquid chromatography-triple quadrupole composite linear ion trap mass spectrometry].

Fingerprints contain important information such as the ingredients ingested by the donor. By analyzing the characteristic components in fingerprints, the donor can be characterized, which would provide insights for investigation of a given case. This approach can also be used in the qualitative monitoring of drug intake. Therefore, the examination of hypotensive drugs in fingerprints has significant value in practical application. This study established a method based on ultra performance liquid chromatography-triple quadrupole composite linear ion trap mass spectrometry (UPLC-Q-TRAP/MS) for the simultaneous determination of 36 hypotensive drugs in fingerprints. The pre-treatment method was based on protein precipitation. A 3×3 cm filter paper was cut into pieces and placed in a 2 mL plastic centrifuge tube after fingerprint collection. Then, 0.50 mL methanol was added, followed by vortex mixing for 1 min and ultrasonic oscillation for 3 min. The filter paper was centrifuged at 12000 r/min for 5 min, and the supernatant was withdrawn for sample analysis. An ACQUITY UPLC® BEH C18 chromatographic column (100 mm×3.0 mm, 1.7 µm) was selected, with 0.01% aqueous formic acid and methanol as mobile phases for gradient elution. MS analysis involved scheduled multiple reaction monitoring-information dependent acquisition-enhanced product ion (SMRM-IDA-EPI) scanning. This method could be used to retrieve library researching during high-sensitivity analysis, which could increase the accuracy of qualitative results. The calibration curves showed good linearity in the range of 0.05-50.00 ng/fingerprint, with correlation coefficients (r) greater than 0.99 for all 36 analytes. The limits of detection and limits of quantification of the 36 hypotensive drugs were 0.001-0.045 ng/fingerprint and 0.002-0.050 ng/fingerprint, respectively. At spiked levels of 0.25, 2.50, 25.00 ng/fingerprint, the matrix effects, recoveries, intra-day precisions, and inter-day precisions of the 36 hypotensive drugs were 79.0%-119.2%, 79.3%-116.2%, 0.2%-18.3%, and 1.6%-19.1%, respectively. This method was used to detect hypotensive drugs in the fingerprints of 87 hypertensive patients, and hypotensive drug intakes were accurately detected in most cases. The established method is operationally simple, with high sensitivity and good selectivity, and it is suitable for screening and testing hypotensive drugs in fingerprints.

Simultaneous screening and analysis of 155 veterinary drugs in livestock foods using ultra-high performance liquid chromatography tandem quadrupole linear-ion-trap mass spectrometry.

Veterinary drugs are widely used to improve the health and growth of livestock. The supervision of these residues is necessary to ensure food safety. A high-throughput method based on Oasis PRiME HLB with solid phase extraction for simultaneous qualitative and quantitative analysis of 155 veterinary drugs in livestock foods was developed by the ultra-high performance liquid chromatography tandem quadrupole linear-ion-trap mass spectrometry (UHPLC-QTRAP-MS). The limits of detection and quantification ranged from 0.5 µg/kg to 5 µg/kg and 2 µg/kg to 20 µg/kg, respectively. For over 85% of the analytes, the recoveries were between 60% and 120%. The positive simulated samples perfectly matched with a purity fit value over 70% from the self-built library. The screening results of UHPLC-QTRAP-MS were almost consistent with UHPLC tandem quadrupole-exactive orbitrap mass spectrometry (UHPLC-Q-Exactive Orbitrap/MS). The evaluated UHPLC-QTRAP-MS method was powerful and reliable for the screening and quantification of veterinary drugs in real samples.

Analytical Methods for Quantification and Identification of Intact Glucosinolates in Arabidopsis Roots Using LC-QqQ(LIT)-MS/MS.

Glucosinolates are biologically active secondary metabolites in Brassicaceae plants that play a critical role in positive and negative interactions between plants and root-associated microbial communities. The aim of this study was to develop a reversed-phase liquid chromatography method to quantify and identify intact glucosinolates in the root of Arabidopsis thaliana (Arabidopsis) grown in non-sterile natural soil by using liquid chromatography-hybrid triple quadruple-linear ion trap (LC-QqQ(LIT)) mass spectrometry. The Synergi Fusion C18-based column was found to be effective for sufficient retention and separation of nine intact glucosinolates without the need for time-consuming desulfation or ion-pairing steps. Method validation results showed satisfactory inter-day and intra-day precision for all glucosinolates except for 4-hydroxyglucobrassicin. Good inter-day and intra-day accuracy and recovery results were observed for glucoiberin, gluconapin, glucobrassicin, 4-methoxyglucobrassicin and neoglucobrassicin. However, for 4-hydroxyglucobrassicin, glucoraphanin and glucoerucin corrections to quantification results might be necessary since the recovery and accuracy results were not optimal. Matrix effects were shown to have a negligible effect on the ionization of all target analytes. The established liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was applied to quantify target intact glucosinolates in Arabidopsis root crude extract of four different wild-type accessions where differences in terms of concentration and composition of intact glucosinolates were observed. Employment of sensitive and selective precursor ion survey scan of m/z 97 in combination with the information-dependent acquisition (IDA) of the enhanced product ion (EPI) dependent scan (Prec97-IDA-EPI) using LC-QqQ(LIT) provided high confidence in structural characterization of diverse intact glucosinolate profiles in complex Arabidopsis root crude extract.

Characterization of the Uncommon Lipid Families in Corynebacterium glutamicum by Mass Spectrometry.

This book chapter provides readers the step-by-step instruction for cell growth, lipid isolation, and lipid analysis to obtain the lipidome of Corynebacterium glutamicum (C. glutamicum) in the genus Corynebacterium, a biotechnologically important bacterium. We separate the lipid families by preparative HPLC with an analytical C-8 column, followed by linear ion-trap multiple stage mass spectrometry (LIT MSn) with high-resolution mass measurement to define the structures of cytidine diphosphate diacylglycerol (CDP-DAG), glucuronosyl diacylglycerol (GlcA-DAG), α-D-mannopyranosyl-(1 â†’ 4)-α-D-glucuronyl diacylglycerol (Man-GlcA-DAG), 1-mycolyl-2-acyl-phosphatidylglycerol (MA-PG), and acyl trehalose monomycolate (acyl-TMM) whose structures have been previously mis-assigned or not defined by mass spectrometric means. We also define the structures of mycolic acid, phosphatidylglycerol, phosphatidylinositol, cardiolipin, trehalose dimycolate lipids in the cell wall. The similarity of the lipidome to that in the Mycobacterium genera is consistent with the notion that Corynebacterium and Mycobacterium are gram-positive bacteria belonging to the suborder Corynebacterineae.

Detection of 4-FMC, 4-MeO-α-PVP, 4-F-α-PVP, and PV8 in blood in a forensic case using liquid chromatography-electrospray ionization linear ion trap mass spectrometry.

We present a case of fatal poisoning by 4-F-methcathinone (4-FMC; also called flephedrone), 4-methoxy-α-pyrrolidinopentiophenone (4-MeO-α-PVP), 4-fluoro-α-pyrrolidinopentiophenone (4-F-α-PVP), and α-pyrrolidinohepatanophenone (PV8). In this study, we compared the mass spectra of 4-FMC, 4-MeO-α-PVP, 4-F-α-PVP, PV8, and α-pyrrolidinohexanophenone between LC-ESI-LIT-MS and GC-EI-MS analyses. Subsequently, we applied LC-ESI-LIT-MS for detection and quantification analyses of 4-FMC, 4-MeO-α-PVP, 4-F-α-PVP, and PV8 in human authentic whole blood samples. More specific mass spectra for the target compounds were obtained with the LC-ESI-LIT-MS qualitative analyses than with the GC-EI-MS analyses, indicating that LC-ESI-LIT-MS was more suitable for the qualitative analysis of cathinones. The LC-ESI-LIT-MS validation data showed moderately good linearity and reproducibility for the compounds in the quantitative analyses at the range of 1-500 ng/mL. The detection limits of four cathinones ranged from 0.1 to 1 ng/mL. The concentrations of 4-FMC, 4-MeO-α-PVP, 4-F-α-PVP, and PV8 in heart whole blood samples were 365, 449, 145, and 218 ng/mL, respectively. Those of the 4 cathinones in femoral vein whole blood samples were 397, 383, 127, and 167 ng/mL, respectively. We can then assume that the cause of death was acute poisoning by a combination of 4-FMC, 4-MeO-α-PVP, 4-F-α-PVP, and PV8. In this article, we present a detailed LC-ESI-LIT-MS procedure for detection and quantification analyses of 4-FMC, 4-MeO-α-PVP, 4-F-α-PVP, and PV8 in authentic human whole blood samples.

Unveiling the biodiversity of lipid species in Corynebacteria- characterization of the uncommon lipid families in C. glutamicum and pathogen C. striatum by mass spectrometry.

Uncommon lipids in biotechnologically important Corynebacterium glutamicum and pathogen Corynebacterium striatum in genus Corynebacterium are isolated and identified by linear ion-trap multiple stage mass spectrometry (LIT MSn) with high resolution mass measurement. We redefined several lipid structures that were previously mis-assigned or not defined, including cytidine diphosphate diacylglycerol (CDP-DAG), glucuronosyl diacylglycerol (GlcA-DAG), (α-d-mannopyranosyl)-(1 â†’ 4)-(α-D-glucuronyl diacyglycerol (Man-GlcA-DAG), 1-mycolyl-2-acyl-phosphatidylglycerol (MA-PG), acyl trehalose monomycolate (acyl-TMM). We also report the structures of mycolic acid, phosphatidylglycerol, phosphatidylinositol, cardiolipin, trehalose dimycolate lipids in which many isomeric structures are present. The LIT MSn approaches afford identification of the functional group, the fatty acid substituents and their regiospecificity in the molecules, revealing the biodiversities of the lipid species in two Corynebacterium strains that have played very different and important roles in human nutrition and health.

[Simultaneous rapid determination of 84 toxic plant constituents in plasma and urine by ultra-performance liquid chromatography- triple quadrupole/linear ion trap mass spectrometry].

An ultra-performance liquid chromatography-triple quadrupole/linear ion trap mass spectrometry (UPLC-Qtrap MS) method was developed for the determination of 84 toxic plant constiuents in plasma and urine. Plasma was precipitated by acetonitrile to remove proteins and then passed through a Prime HLB SPE column to remove phospholipids, while urine was diluted with methanol. Chromatographic separation of the analytes was achieved on an Acquity BEH C18 column (100 mm×2.1 mm, 1.7 µm) by gradient elution using the mobile phase of 0.1% (v/v) formic acid and 2 mmol/L ammonium formate both in 97% (v/v) acetonitrile aqueous solution and water. Electrospray ionization mass spectrometry was carried out in the positive ion mode with multiple reaction monitoring-information dependent acquisition-enhanced product ion scan mode (MRM-IDA-EPI). The 84 analytes were quantified by the matrix working standard curve internal standard method, and a good linear relationship was observed, with correlation coefficients of ≥ 0.9911. The limits of detection (LODs) in plasma and urine were 0.01-1 µg/L and 0.03-2 µg/L, respectively. The intra- and inter-day precisions of these analytes were 0.7%-18.4% and 1.1%-18.5%, and the accuracy of all analytes ranged from 70.6% to 124.5%. This method is simple, sensitive, and accurate for the measurement of these analytes in plasma and urine for both clinical and forensic applications.

Differentiation of AB-FUBINACA and its five positional isomers using liquid chromatography-electrospray ionization-linear ion trap mass spectrometry and triple quadrupole mass spectrometry.

PURPOSE: Positional isomer differentiation is crucial for forensic analysis. The aim of this study was to differentiate AB-FUBINACA positional isomers using liquid chromatography (LC)-electrospray ionization (ESI)-linear ion trap mass spectrometry (LIT-MS) and LC-ESI-triple quadrupole mass spectrometry (QqQ-MS). METHODS: AB-FUBINACA, its two fluorine positional isomers on the phenyl ring, and three methyl positional isomers in the carboxamide side chain were analyzed by LC-ESI-LIT-MS and LC-ESI-QqQ-MS. RESULTS: Four of the positional isomers, excluding AB-FUBINACA and its 3-fluorobenzyl isomer, were chromatographically separated on an ODS column in isocratic mode. ESI-LIT-MS could discriminate only three isomers, i.e., the 2-fluorobenzyl isomer, the N-(1-amino-2-methyl-1-oxobutan-2-yl) isomer, and the N-(1-amino-1-oxobutan-2-yl)-N-methyl isomer, based on their characteristic product ions observed at the MS3 stage in negative mode. ESI-QqQ-MS differentiated all six isomers in terms of the relative abundances of the product ions that contained the isomeric moieties involved in collision-induced dissociation reactions. The six isomers were more clearly and significantly differentiated upon comparison of the logarithmic values of the product ion abundance ratios as a function of collision energy. CONCLUSIONS: The present LC-MS methodologies were useful for the differentiation of a series of AB-FUBINACA positional isomers.

The plasma lipidome in acute myeloid leukemia at diagnosis in relation to clinical disease features.

BACKGROUND: Early studies established that certain lipids were lower in acute myeloid leukemia (AML) cells than normal leukocytes. Because lipids are now known to play an important role in cell signaling and regulation of homeostasis, and are often perturbed in malignancies, we undertook a comprehensive lipidomic survey of plasma from AML patients at time of diagnosis and also healthy blood donors. METHODS: Plasma lipid profiles were measured using three mass spectrometry platforms in 20 AML patients and 20 healthy blood donors. Data were collected on total cholesterol and fatty acids, fatty acid amides, glycerolipids, phospholipids, sphingolipids, cholesterol esters, coenzyme Q10 and eicosanoids. RESULTS: We observed a depletion of plasma total fatty acids and cholesterol, but an increase in certain free fatty acids with the observed decline in sphingolipids, phosphocholines, triglycerides and cholesterol esters probably driven by enhanced fatty acid oxidation in AML cells. Arachidonic acid and precursors were elevated in AML, particularly in patients with high bone marrow (BM) or peripheral blasts and unfavorable prognostic risk. PGF2α was also elevated, in patients with low BM or peripheral blasts and with a favorable prognostic risk. A broad panoply of lipid classes is altered in AML plasma, pointing to disturbances of several lipid metabolic interconversions, in particular in relation to blast cell counts and prognostic risk. CONCLUSIONS: These data indicate potential roles played by lipids in AML heterogeneity and disease outcome. GENERAL SIGNIFICANCE: Enhanced catabolism of several lipid classes increases prognostic risk while plasma PGF2α may be a marker for reduced prognostic risk in AML.

Improved sensitivity of ochratoxin A analysis in coffee using high-performance liquid chromatography with hybrid triple quadrupole-linear ion trap mass spectrometry (LC-QqQLIT-MS/MS).

A novel and sensitive method utilising high-performance liquid chromatography coupled to triple quadrupole-linear ion trap mass spectrometry (LC-QqQLIT-MS/MS) was developed in order to analyse the content of ochratoxin A (OTA) in coffee samples. The introduction of the triple-stage MS scanning mode (MS(3)) has been shown to increase greatly sensitivity and selectivity by eliminating the high chromatographic baseline caused by interference of complex coffee matrices. The analysis included the sample preparation procedure involving extraction of OTA using a methanol-water mixture and clean-up by immunoaffinity columns and detection using the MS(3) scanning mode of LC-QqQLIT-MS/MS. The proposed method offered a good linear correlation (r(2) > 0.998), excellent precision (RSD < 2.9%) and recovery (94%). The limit of quantification (LOQ) for coffee beans and espresso beverages was 0.010 and 0.003 µg kg(-1), respectively. The developed procedure was compared with traditional methods employing liquid chromatography coupled to fluorescent and tandem quadrupole detectors in conjunction with QuEChERS and solid-phase extraction. The proposed method was successfully applied to the determination of OTA in 15 samples of coffee beans and in 15 samples of espresso coffee beverages obtained from the Latvian market. OTA was found in 10 samples of coffee beans and in two samples of espresso in the ranges of 0.018-1.80 µg kg(-1) and 0.020-0.440 µg l(-1), respectively. No samples exceeded the maximum permitted level of OTA in the European Union (5.0 µg kg(-1)).

Simultaneous qualitative and quantitative analysis of 21 mycotoxins in Radix Paeoniae Alba by ultra-high performance liquid chromatography quadrupole linear ion trap mass spectrometry and QuEChERS for sample preparation.

A high-throughput method for simultaneous qualitative and quantitative analysis of 21 mycotoxins in Radix Paeoniae Alba (RPA) was developed by coupling the modified QuEChERS method with ultra-high performance liquid chromatography quadrupole linear ion trap mass spectrometry (UHPLC-QqLIT-MS). The 21 mycotoxins were extracted and cleaned up using QuEChERS-based procedure, then further separated on a C18 column and detected by a hybrid triple quadrupole linear ion trap mass spectrometer equipped with electrospray ionization source in the multiple reaction monitoring-information dependent acquisition-enhanced product ion (MRM-IDA-EPI) mode. Under this technique, 13 mycotoxins were detected using acetonitrile and water containing 0.1% formic acid as the mobile phase in positive mode while the other 8 mycotoxins were detected using acetonitrile and water containing 0.1% ammonia as the mobile phase in negative mode. The calibration curves of all analytes showed good linearity (r(2)>0.995) within test ranges. The limits of detection and quantification ranged from 0.031 to 5.4µg/kg and 0.20 to 22µg/kg, respectively. Additionally, recoveries were all above 75.3% with relative standard deviations within 15%. The method proposed herein with significant advantages including simple pretreatment, rapid determination as well as high sensitivity, accuracy and throughput would be a preferred candidate for the determination and quantification of multi-class mycotoxin contaminants in real samples.

An integrated strategy to quantitatively differentiate chemome between Cistanche deserticola and C. tubulosa using high performance liquid chromatography-hybrid triple quadrupole-linear ion trap mass spectrometry.

It is important to conduct large-scale detection, identification, and quantitation of metabolites in a given sample. Herein, a practical strategy was proposed to quantitatively compare the chemome between Cistanche deserticola (CD) and C. tubulosa (CT), which have been widely believed as the ideal edible and medicinal plants for conquering the deserts. The entire workflow was implemented on high performance liquid chromatography-hybrid triple quadrupole-linear ion trap mass spectrometer and consisted of three primary steps: (1) component detection and identification, various mass spectrometric approaches were applied to globally screen the chemical constituents, and structural elucidation was achieved by comparing with authentic compounds, analyzing MS(2) spectra, and referring to the literature along with accessible databases; (2) comprehensive relative quantitation, scheduled multiple reaction monitoring algorithm was introduced for relative quantitation of all detected ingredients; and (3) chemome comparison, the quantitative dataset was subjected for multivariate statistical analysis to carry out comparative study. A total of 513 metabolites were detected and relatively quantitated, and 379 ones were annotated. Betaine, Krebs cycle intermediates, phenylethanoid glycosides, and iridoids were picked out as the chemical markers being responsible for the discrimination of the chemical profiles between CD and CT. Above all, the quantitative chemome of CD and CT were exhaustively characterized and compared, which could advance their values concerning drug development, economics, and desertification control. The proposed strategy is expected as a reliable choice for widely targeted metabolomics of plants.

Molecular formula analysis of fragment ions by isotope-selective collision-induced dissociation tandem mass spectrometry of pharmacologically active compounds.

The purpose of this work is to explore the mass fragment characterization of commonly used drugs through a novel approach, which involves isotope-selective tandem mass spectrometry (MS/MS). Collision-induced dissociation (CID) was performed with a low-resolution linear ion trap mass spectrometer in positive electrospray ionization. Three pharmacologically active ingredients, i.e. omeprazole, meloxicam and brinzolamide, selected as model compounds in their own formulation, were investigated as a sodiated adduct [C17 H19 N3 O3 S + Na](+) (omeprazole) and as protonated adducts, [C14 H13 N3 O4 S2 + H](+) and [C12 H21 N3 O5 S3 + H](+) , meloxicam and brinzolamide, respectively. Selecting a narrow window of ±0.5 m/z units, precursor ion fragmentation by CID-MS/MS of isotopologues A + 0, A + 1 and A + 2 was found very useful to confirm the chemical formula of product ions, thus aiding the establishment of characteristic fragmentation pathways of all three examined compounds. The correctness of putative molecular formula of product ions was easily demonstrated by exploiting the isotope peak abundance ratios (i.e. IF+0 /IF+1 and IF+0 /IF+2 ) as simple constraints in low-resolution MS instrumentations.