Search results for "PLC"
showing 10 items of 242 documents
Pharmaceutical properties of supramolecular assembly of co-loaded cardanol/triazole-halloysite systems
2015
Halloysite nanotubes were explored as drug carrier for cardanol, which is considered as a promising natural anticancer active species. To this aim, besides the pristine nanoclay, a chemical modification of the nanocarrier was performed by attaching triazolium salts with different hydrophobicity at the outer surface of the hollow nanotubes. The interaction between cardanol and nanotubes was highlighted in solution by HPLC. This method proved the loading of the drug into the nanotubes. The solid dried complexes formed by pristine and modified halloysite with the cardanol were characterized by IR spectroscopy, thermogravimetric analysis as well as water contact angle to evidence the structure,…
Profiling of compounds and degradation products from the postharvest treatment of pears and apples by ultra-high pressure liquid chromatography quadr…
2010
This study deals with a simple strategy to pinpoint potential unknown compounds in full scan mass spectrometry (MS) experiments. Forty samples of apples and pears intended for human consumption were analyzed by ultra-high performance liquid chromatography quadrupole-time-of-flight (UPLC–QqTOF-MS), after extraction of the possible contaminants by rinsing the peel of the fruit with ethyl acetate. The peaks were visually recognized in the total ion chromatogram (TIC). Two major types of postharvest treatments were detected in this set of samples: imazalil (IMZ)/ethoxyquin (EQ) and thiabendazole (TBZ)/diphenylamine (DPA). The present work also describes the metabolites formed by degradation of …
Determination of the cultivar and aging of Sicilian olive oils using HPLC-MS and linear discriminant analysis
2010
A large number of certified samples (84) of Sicilian olive oils arising from the eight cultivars most represented in Sicily (Biancolilla, Cerasuola, Moresca, Nocellara del Belice, Nocellara Etnea, Oglialora Messinese, Brandofino and Tonda Iblea) have been collected and analyzed by HPLC/MS using an atmospheric pressure chemical ionization (APCI) source. The sample preparation is very simple; in fact, the oil samples are diluted without any chemical derivatization. A following statistical data treatment by general discriminant analysis (GDA) allows the determination of the olive oil cultivar. Furthermore, changes in the composition of glyceridic components of the olive oils lead to easy discr…
Selective labelling of melittin with a fluorescent dansylcadaverine probe using guinea-pig liver transglutaminase
1991
Abstract Melittin, a C-terminal peptide, incorporated the fluorescent probe monodansylcadaverine (DNC) when catalysed by guinea-pig liver transglutaminase and Ca2+, as determined by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). A 1:1 adduct DNC-melittin was identified in which a single glutamine residue out of two, i.e. Gln25, acts as acyl donor. Incubation of melittin with transglutaminase in the absence of DNC originated high molecular mass complexes indicative that the peptide lysine residue can act as an acyl acceptor. The DNC-melittin was about 3 times more active in the lysis of red cell membranes than native melittin. Fluorescence study of the lab…
Analysis of β2-agonists in cattle hair samples using a rapid UHPLC–ESI–MS/MS method
2016
A simple and efficient method was developed for simultaneous analysis of five illegal residual β2-agonists in cattle hair. β2-Agonists were quantified by ultra high performance liquid chromatography coupled with electrospray ionisation tandem mass spectrometry operating in positive multiple-reaction monitoring mode. The method was validated as quantitative confirmatory method according to the EU Decision 2002/657/EC: instrumental linearity, specificity, precision, recovery, decision limit (CCα) and detection capability (CCβ) were evaluated. The recovery were greater than 90% and the method appeared suitable for the control of these β2-agonists in cattle hair samples with LOQ values between …
Aflatoxinas, tricotecenos de tipo A y hongos productores en maíz y avena. Nuevos antifúngicos y su impacto en salud
2021
Los hongos filamentosos están ampliamente distribuidos en la naturaleza y existen especies causantes de infecciones en el hombre, animales o plantas, o productores de micotoxinas que pueden ocasionar intoxicaciones agudas o crónicas. Los hongos toxigénicos pertenecen principalmente a los géneros Aspergillus, Fusarium y Penicillium. El cambio climático facilita la adaptación de especies toxigénicas a nuevas condiciones de estrés térmico/hídrico, lo cual afecta a su distribución geográfica en cultivos básicos, como los cereales. Ello facilita la dominancia de las especies mejor adaptadas, lo que se traduce en la emergencia de ciertas micotoxinas en los cereales como las aflatoxinas (AF) o tri…
A metabolomic study of yeast/bacteria interactions
2015
As a complex microbial ecosystem, wine is a particularly interesting model for studying interactions between microorganisms. Contact-independent interactions (indirect interactions) between the yeast Saccharomyces cerevisae and the lactic acid bacterium Oenococcus oeni have a direct effect on malolactic fermentation (MLF), induction and completion, which is an important factor in wine quality. Yeast strains could be classified as MLF+ phenotype if it usually stimulates the bacterial growth or MLF- in the opposite case. The known metabolites that stimulate or inhibit the MLF cannot always explain the phenotypic distinction. In this work, a multidisciplinary workflow combining non-targeted me…
Development, modeling and simulation of test equipment for subsea choke valves
2014
Masteroppgave i mekatronikk MAS 500 Universitetet i Agder 2014 As a step toward being more e_ective and to improve test procedures, GE Oil & Gas wants to develop a workshoptool to automate the testing of Choke Valves. The Choke Valve Workshop Tool (CVWT) main functionis to operate the Hydraulic Stepping Actuator automatically by providing controlled pressure pulses. Electricaland hydraulic equipment will have an interface allowing the test equipment to be connected and used on awide range of Choke Valves. Test results will be transferred and stored automatically based on current need. Adetailed description of the planned CVWT including a complete control system and a Human Machine Interface…
A simple high-performance liquid chromatography (HPLC) method for the measurement of pyridoxal-5-phosphate and 4-pyridoxic acid in human plasma.
2014
Abstract Background Low concentration of plasma pyridoxal-5-phosphate (PLP) is associated with hyperhomocysteinemia and inflammation. Most methods for the measurement of plasma PLP require large specimen volume and involve the use of toxic reagents. Methods We have developed a HPLC method for the measurement of PLP and 4-pyridoxic acid (4-PA) in plasma, which requires small specimen volume. The samples are prepared without adding any toxic reagents. Furthermore, we have examined whether intake of vitamin B 6 affects the concentration of plasma PLP and 4-PA. Results The coefficient of variation of the method was 6% and the recovery of the added vitamin in plasma was about 100%. The concentra…
High precision mass measurements for wine metabolomics
2014
An overview of the critical steps for the non-targeted Ultra-High Performance Liquid Chromatography coupled with Quadrupole Time-of-Flight Mass Spectrometry (UPLC-Q-ToF-MS) analysis of wine chemistry is given, ranging from the study design, data preprocessing and statistical analyses, to markers identification. UPLC-Q-ToF-MS data was enhanced by the alignment of exact mass data from FTICR-MS, and marker peaks were identified using UPLC-Q-ToF-MS(2). In combination with multivariate statistical tools and the annotation of peaks with metabolites from relevant databases, this analytical process provides a fine description of the chemical complexity of wines, as exemplified in the case of red (P…