This study was conducted to analyze carotenoids from tomatoes by high-performance liquid chromatography using reversed-phase C18 silica having cross-linked end-capping with diode array and mass spectrometric detection. An efficient gradient elution system was developed to achieve good and reliable separation of both major and minor carotenoids as well as their isomers. Resolution of lycopene, β...

Several isocratic separations for the determination of 20 steroids (STER) in animal feeding water samples (AFWS) from drinking-trough by LC using a mobile phase ACN/H(2)O (35:65 v/v) and different RP columns (Hypersil C18, Gemini C18 (GM), Purospher Star C18, Synergi Max C12, and Synergi Fusion) and UV detection were obtained. The elution order was the same: a first group of corticoids (CC) was...

Pre-column conversion of ammonia and a number of aliphatic amines into phenylthiourea or its derivatives by reaction with phenyl isothiocyanate, followed by HPLC, has been used for their determination in environmental waters. Optimum conversion was found when the reaction was carried out in sodium hydrogencarbonate– carbonate medium at 40 °C for 15 min. Well separated peaks were obtained on a C...

We have determined routinely administered benzodiazepines and some of their metabolites in clinical samples by using on-line column switching for sample clean-up and reversed-phase high-pressure liquid chromatography (HPLC). The plasma sample is directly injected onto a cyanopropyl (CN) pre-column, washed with buffer, and eluted onto an analytical column (C18, octadecylsilane). Analytical recov...

Vietnam's sea is assessed to be very diverse and rich in seaweed species. It about 1000 different species of seaweed, which more than 800 have been identified, classify into genus, families, classes, phylums, continuously updated from the 1950s present. Previous studies by Vietnamese international scientists shown that lipids contain many valuable active ingredients such as acids C20: 4n-6 (AA)...

A HPLC method for simultaneous determination of diclofenac sodium and papaverine hydrochloride in tablets was developed and validated. The determination was performed with a Zorbax SB-C18 column, mobile phase: methanol-water (60:40, v/v), flow rate: 1 mL min(-1) and UV detection at 278 nm.

A simple, sensitive, rapid, precise and economical reverse phase HPLC method has been developed for the estimation of valsartan from pharmaceutical dosage forms. The was carried out using Chromatographic conditions were established by employing a C18 analytical phenomenal (Kinetex) column (5micron -C18, 250x4.6mm) with mobile phosphate buffer (PH 3.5) acetonitrile in 60:40 ratio. sample injecte...

A facile method for quantifying the concentration of the powerful and widely available hallucinogen salvinorin A (a selective kappa opioid agonist) from non-human primate cerebrospinal fluid (CSF) and human plasma has been developed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in positive electrospray ionization (ESI) mode. With CSF solid phase extraction can be avoided compl...

a validated hplc method was developed to determine doxorubicin concentration in a small volume of rat plasma (60 µl) with convenient fluorescence detection. sample preparation includes a simple one-step liquid-liquid extraction using minimum amount of organic solvent, with extraction recoveries more than 95%. the analysis was accomplished using perfectsil c18 column maintained at 35 °c and a mo...