Search results for "liquid"
showing 10 items of 4351 documents
Fourier-transform infrared study of the switching process in a ferroelectric liquid crystalline polymer
1995
The implementation of the step-scan technique on our spectrometer enabled us to follow the electric field induced reorientation dynamics of different molecular segments of the ferroelectric liquid crystalline polymer [Si(Me)(R)O/Si(Me)(R')O/Si(Me) 2 O] n (R= (CH 2 ) 11 OPhCOOPhOCO * CHCl * CH(Me)(Et); R'= (CH 2 ) 11 OPhN=NPhO * CH(Me)(Hex)) on a sub-millisecond time scale. It was detected that not only the mesogen but also the spacer and at least part of the backbone take part in the reorientation process
Analysis of pesticides in fruits by pressurized liquid extraction and liquid chromatography-ion trap-triple stage mass spectrometry.
2005
A multi-residue method using pressurized liquid extraction (PLE) and liquid chromatography-quadrupole ion trap-triple stage mass spectrometry (LC-IT-MS(3)) has been developed for determining trace levels of pesticides in fruits. The selected pesticides can be distinguished in: benzimidazoles and azoles, organophosphorus, carbamates, neonicotinoids, and acaricides. PLE has been optimized to extract these pesticide residues from oranges and peaches by studying the effect of experimental variables on PLE efficiency. Samples were extracted at high temperature and pressure (75 degrees C and 1500psi) using ethyl acetate as extraction solvent and acidic alumina as drying agent. The recoveries obta…
SANIST: optimization of a technology for compound identification based on the European Union directive with applications in forensic, pharmaceutical …
2016
Electrospray Ionization and collision induced dissociation tandem mass spectrometry are usually employed to obtain compound identification through a mass spectra match. Different algorithms have been developed for this purpose (for example the nist match algorithm). These approaches compare the tandem mass spectra of the unknown analyte with the tandem mass spectra spectra of known compounds inserted in a database. The compounds are usually identified on the basis of spectral match value associated with a probability of recognition. However, this approach is not usually applied to multiple reaction monitoring transition spectra achieved by means of triple quadrupole apparatus, mainly due to…
The use of imidazolium group-containing Bronsted acids for masspectrometric determination of biogenic amines in alcoholic beverages
2017
Darbā ir izstrādāta metode sešu biogēno amīnu masspektrometriskai noteikšanai alkoholiskos dzērienos. Metodes pamatā ir kompleksu veidošanās starp biogēniem amīniem un imidazolija grupu saturošu Brensteda skābi, kas nodrošina ātru un selektīvu analīzi bez parauga sagatavošanas. Darba gaitā ir izpētīta vairāku masspektrometra parametru ietekme uz biogēno amīnu kompleksu rašanos, un izvēlētas specifiskās MRM pārejas. Metodes aprobācijai izvēlēti un analizēti astoņi alkoholiskie dzērieni.
Update on the detection of beta-exotoxin in Bacillus thuringiensis strains by HPLC analysis.
2001
Aims: The current work aimed to study the presence of β-exotoxin by high-performance liquid chromatography (HPLC) in supernatant fluids from final whole cultures of the 69 type strains and 13 subtypes of Bacillus thuringiensis strains, as well as from some insecticidal strains. Methods and Results: Results from HPLC and bioassays with Ephestia kuhniella (Lepidoptera Pyralidae) were compared. Type I β-exotoxin was only detected in type strains representing serotypes H1, H9 and H10a,10b. Discrepancies between HPLC and bioassays were found in H8a,8b and some insecticidal strains, which suggests the occurrence of another soluble toxin different from type I β-exotoxin, possibly type II β-exotoxi…
VECTOR-BARYON DYNAMICS IN γN → K0Σ REACTIONS
2014
A coupled channel model for the interaction of vector mesons with baryons is employed in the study of the γp → K0Σ+ reaction around the K*Λ and K*Σ thresholds, where the recent CBELSA/TAPS cross section shows a sudden drop and the differential cross section experiences a transition from a forward-peaked distribution to a flat one. A delicate interference between amplitudes having K*Λ and K*Σ intermediate states is found. The sharp downfall is dictated by the presence of a N* resonance produced by our model, a feature that we have employed to infer its properties. Predictions for the complementary γn → K0Σ0 reaction are also given.
Polymerized Ionic Liquids with Polythiophene Backbones: Self-Assembly, Thermal Properties, and Ion Conduction
2018
Single ion conductors, based on polymerized ionic liquids (PILs) with a polythiophene backbone bearing imidazolium salts with butyl, hexyl, octyl, and decyl side groups and six different counterani...
ChemInform Abstract: Dialkylimidazolium Dimethyl Phosphates as Solvents and Catalysts for the Knoevenagel Condensation Reaction.
2014
Knoevenagel condensation between benzaldehyde and ethyl cyanoacetate in the presence of an equimolar amount of 1,3-dialkylimidazolium dimethyl phosphate ionic liquids is investigated.
Reactivity of anticancer metallodrugs with serum proteins: New insights from size exclusion chromatography-ICP-MS and ESI-MS
2010
International audience; A method based on the coupling of high resolution size-exclusion liquid chromatography using a polymer stationary phase with inductively coupled plasma mass spectrometry was developed to study the interactions of two metallodrugs - cisplatin and RAPTA-T - with the serum proteins albumin and transferrin. In contrast to previous approaches, the technique allowed the total recovery of the metals from the column and was able to discriminate between the different species of the metallodrugs and their complexes with the proteins at femtomolar detection levels. Metal binding was found to be dependent on the protein concentration and on the incubation time of the sample. Cis…
The droplet evaporation/condensation transition in a finite volume
2003
A fluid in the NVT ensemble at T less than the critical temperature T_c and rho = N/V somewhat in excess of rho_coex (density of the saturated gas in the gas-liquid transition) is considered. For V->infinity, a macroscopic liquid droplet coexists with surrounding saturated gas according to the lever rule. For finite V, droplets can only exist if they exceed a minimum size. A (rounded) first order transition of the system occurs when the droplet evaporates into the supersaturated gas.Simulation evidence for this transition is given for a Lennard-Jones model and interpreted by a phenomenological theory. At the transition, the chemical potential difference mu_t-mu_coex scales like L^(-d/(d+…