Search results for " Analytical"
showing 10 items of 1453 documents
MetProc: Separating Measurement Artifacts from True Metabolites in an Untargeted Metabolomics Experiment
2019
High-throughput metabolomics using liquid chromatography and mass spectrometry (LC/MS) provides a useful method to identify biomarkers of disease and explore biological systems. However, the majority of metabolic features detected from untargeted metabolomics experiments have unknown ion signatures, making it critical that data should be thoroughly quality controlled to avoid analyzing false signals. Here, we present a postalignment method relying on intermittent pooled study samples to separate genuine metabolic features from potential measurement artifacts. We apply the method to lipid metabolite data from the PREDIMED (PREvención con DIeta MEDi-terránea) study to demonstrate clear remova…
Multicentric study of the effect of pre-analytical variables in the quality of plasma samples stored in biobanks using different complementary proteo…
2016
12 páginas, 7 figuras.-- Jesús Mateos ... et al.
Self-packed core shell nano liquid chromatography columns and silica-based monolithic trap columns for targeted proteomics.
2016
Self-preparation of nano liquid chromatography (nLC) columns has advantages regarding cost and flexibility. For targeted proteomics, we evaluated several approaches for particle-packing nLC columns and manufacturing fritless silica-based monolithic trap columns (50μm inner diameter). Our preferred approach for nLC column preparation was to magnetically stir Accucore core shell particles (C18 stationary phase) in ACN/water (80/20, v/v) suspensions during pressure-driven filling of polymer-fritted standard fused silica capillaries. The columns were ready for use about one hour after preparation had begun. They had comparable peak capacities (peptides) to commercial columns, and satisfactory w…
Orange proteomic fingerprinting: From fruit to commercial juices.
2015
Combinatorial peptide ligand library technology, coupled to mass spectrometry, has been applied to extensively map the proteome of orange pulp and peel and, via this fingerprinting, to detect its presence in commercial orange juices and drinks. The native and denaturing extraction protocols have captured 1109 orange proteins, as identified by LC-MS/MS. This proteomic map has been searched in an orange concentrate, from a Spanish juice manufacturer, as well as in commercial orange juices and soft drinks. The presence of numerous orange proteins in commercial juices has demonstrated the genuineness of these products, prepared by using orange fruits as original ingredients. However, the low nu…
Label-free quantification in ion mobility-enhanced data-independent acquisition proteomics.
2016
Unbiased data-independent acquisition (DIA) strategies have gained increased popularity in the field of quantitative proteomics. The integration of ion mobility separation (IMS) into DIA workflows provides an additional dimension of separation to liquid chromatography-mass spectrometry (LC-MS), and it increases the achievable analytical depth of DIA approaches. Here we provide a detailed protocol for a label-free quantitative proteomics workflow based on ion mobility-enhanced DIA, which synchronizes precursor ion drift times with collision energies to improve precursor fragmentation efficiency. The protocol comprises a detailed description of all major steps including instrument setup, filt…
A combined physical-chemical and microbiological approach to unveil the fabrication, provenance, and state of conservation of the Kinkarakawa-gami ar…
2020
AbstractKinkarakawa-gami wallpapers are unique works of art produced in Japan between 1870 and 1905 and exported in European countries, although only few examples are nowadays present in Europe. So far, neither the wallpapers nor the composing materials have been characterised, limiting the effective conservation–restoration of these artefacts accounting also for the potential deteriogen effects of microorganisms populating them. In the present study, four Kinkarakawa-gami wallpapers were analysed combining physical–chemical and microbiological approaches to obtain information regarding the artefacts’ manufacture, composition, dating, and their microbial community. The validity of these met…
Fast UPLC/PDA determination of squalene in Sicilian P.D.O. pistachio from Bronte: Optimization of oil extraction method and analytical characterizati…
2017
Abstract A fast reversed-phase UPLC method was developed for squalene determination in Sicilian pistachio samples that entry in the European register of the products with P.D.O. In the present study the SPE procedure was optimized for the squalene extraction prior to the UPLC/PDA analysis. The precision of the full analytical procedure was satisfactory and the mean recoveries were 92.8 ± 0.3% and 96.6 ± 0.1% for 25 and 50 mg L−1 level of addition, respectively. Selected chromatographic conditions allowed a very fast squalene determination; in fact it was well separated in ∼0.54 min with good resolution. Squalene was detected in all the pistachio samples analyzed and the levels ranged from 5…
Comparison of Two Solid-Phase Extraction (SPE) Methods for the Identification and Quantification of Porcine Retinal Protein Markers by LC-MS/MS
2018
Proper sample preparation protocols represent a critical step for liquid chromatography-mass spectrometry (LC-MS)-based proteomic study designs and influence the speed, performance and automation of high-throughput data acquisition. The main objective of this study was to compare two commercial solid-phase extraction (SPE)-based sample preparation protocols (comprising SOLAµ
Validated HPLC-UV detection method for the simultaneous determination of ceftolozane and tazobactam in human plasma
2018
Aim: A simple, rapid, economical and sensitive HPLC-UV method was developed for the simultaneous quantification of ceftolozane and tazobactam in plasma samples. Methodology: After deproteinization followed by a liquid–liquid back-extraction, the compounds were separated on a C18 column (150 mm × 4.6 mm, 5 μm) with UV-visible detection at 220 nm. The mobile phase consisted of acetonitrile and potassium dihydrogenphosphate buffer at pH 3.0 (8:92, v/v), delivered isocratically at a flow rate of 1.0 ml/min and at a column oven temperature of 30°C. Cefepime was used as an internal standard. Results: Linearity was achieved in the concentration range of 0.50–100.00 μg/ml for ceftolozane and 0.25–…
Multi-approach metabolomics analysis and artificial simplified phytocomplexes reveal cultivar-dependent synergy between polyphenols and ascorbic acid…
2017
Fruits of the sweet cherry (Prunus avium L.) accumulate a range of antioxidants that can help to prevent cardiovascular disease, inflammation and cancer. We tested the in vitro antioxidant activity of 18 sweet cherry cultivars collected from 12 farms in the protected geographical indication region of Marostica (Vicenza, Italy) during two growing seasons. Multiple targeted and untargeted metabolomics approaches (NMR, LC-MS, HPLC-DAD, HPLC-UV) as well as artificial simplified phytocomplexes representing the cultivars Sandra Tardiva, Sandra and Grace Star were then used to determine whether the total antioxidant activity reflected the additive effects of each compound or resulted from synergis…