Trifluoroacetic acid

In this study, an evaluation of the enantioselective of a chiral flavanone with 2'-OH substitution (5,7,2'- trihydroxyflavanone) on ring C was studied by high performance liquid chromatography using the cellulose tris(3,5- dimethylphenyl carbamate)-based stationary phase with n-hexane and iso-propanol doped with 0.1% (v/v) trifluoroacetic acid as a mobile phase.

6p dianmotminh02 03-05-2024 1 1   Download

In this study, the pre-purified pigment extracts from the cactus fruits of Opuntia stricta var. dillenii (Opuntia) and vegetable leaves from Atriplex hortensis var. rubra (Atriplex) were fractionated by high performance CCC (HPCCC) using the ion-pair solvent system of tert.-butylmethyl-ether/n-butanol/acetonitrile/water, trifluoroacetic acid (TBMe/n-BuOH/ACN/water) (v/v/v/v, 2:2:1:5, 1% TFA).

7p vicedric 08-02-2023 5 2   Download

The aim of this study was the determination of chromatographic profiles of major whey proteins (WP): α-lactalbumin (α-La), β-lactoglobulin A and B, (β-Lg A and B), bovine serum albumin (BSA) in dairy beverages based on Zonar milk serum. The studied WP were separated by high-performance liquid chromatography (HPLC) on Aeris XB-C18 column using gradient elution with 0.1% trifluoroacetic acid (TFA) in water and 0.1% TFA in 80% acetonitrile, at 214 nm detection.

11p lyhuyenthu 31-01-2023 2 2   Download

A method for the quantitative determination of the protein composition of adenovirus-vector based vaccines was developed. The final method used RP-UPLC with UV absorbance detection, a C4 column (300Å, 1.7 m, 2.1 × 150 mm), and a water- acetonitrile (ACN) gradient containing trifluoroacetic acid (TFA) as ion-pairing agent.

8p viginny 23-12-2022 6 3   Download

The amount of those newly revealed CBD transformation products depends on the GC injector temperature and on the extrahent type when extracts of the supernatants centrifuged from human plasma samples are analyzed after their preliminary protein precipitation by trifuoroacetic acid.

8p viginny 23-12-2022 8 3   Download

We evaluate here different analytical strategies for the chromatographic separation and determination of N-acetyl-5-methoxytryptamine (MEL) and its oxidative metabolites N1-acetyl-N2-formyl-5- methoxykynuramine (AFMK), N1-acetyl-5-methoxykynuramine (AMK) and cyclic 3-hydroxymelatonin (c3OHM) in cell culture samples.

11p viginny 23-12-2022 7 3   Download

(BQ) Ebook Part 1 presents the following content: Principles and topical applications of 19F NMR spectrometry; partitioning of organofluorine compounds in the environment; atmospheric chemistry and environmental impact of hydrofluorocarbons (HFCs) and hydrofluoroethers (HFEs); trifluoroacetic acid and longer chain perfluoro acids – sources and analysis; naturally occurring organofluorines; degradation and transformation of organic fluorine compounds.

201p runordie7 30-08-2022 8 2   Download

Coumarin-based chromogenic and fluorogenic dye 4 was designed and synthesized. The photophysical properties of 4 were determined in solvents with different polarities. Protonation affinity was determined by adding trifluoroacetic acid (TFA) to a dichloromethane solution of dye 4 utilizing the UV-Vis and fluorescence titration methods. The protonation region was investigated by using the 1H NMR method. Additionally, DFT and TDDFT studies were performed to support the structural and absorption spectral properties of 4.

12p tudichquannguyet 29-11-2021 11 1   Download

The present study investigated comparing HCl and TFA to consider which acid performed better on hydrolyzing EPS. The results of the study might create a premise for further studies on the chemical structure of EPS.

8p nguaconbaynhay11 16-04-2021 10 2   Download

We developed a modified Quick, Easy, Cheap, Effective, Rugged, and Safe (CEN QuEChERS) extraction method coupled with liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI+ /MS-MS) to identify and quantify residues of three botanical alkaloids, namely, scopolamine, L-hyoscyamine, and sparteine, in animal-derived foods, including porcine muscle, egg, and milk. A combination of ethylenediaminetetraacetic acid disodium buffer and acetonitrile acidified with 0.

8p trinhthamhodang1 14-11-2019 23 1   Download

Two stereoisomers of benzo[a]furo[2,3-g]quinolizine derivatives were obtained by alkylation of stereoisomeric 7a-methyl-2-oxo-5-phenylfuro[2,3-c]piperidines with methallyl chloride and subsequent cyclization of alkylated products in the mixture of trifluoroacetic and concentrated sulphuric acids. It is interesting to find that the cis-quinolizine, upon heating to 150o C in glacial acetic acid, is isomerized to the trans-isomer.

4p uocvong04 24-09-2015 31 2   Download

The comparative study of the content and structure characteristics of fucoidans from five Sargassum brown seaweed species in the south provinces of Vietnam was conducted. The yield of fucoidans was ca. 4% (w/w) based on dry seaweed. The percentage of sulfate and uronic acid content was determined by Scott method. Fucoidans were hydrolyzed with trifluoroacetic acid, acetylated and their L-fucose, D-xylose, D-rhamnose, D-mannose, D-glucose, and D-galactose contents were identified by gas chromatography. All polysaccharides isolated from Sargassum polycystum C. Agardh, S. mcclurei Setchell, S.

4p uocvong04 24-09-2015 74 8   Download