Alguns triterpenos quinonametídicos são conhecidos pela sua citotoxicidade, havendo relatos destas substâncias em várias espécies do gênero Maytenus (Celastraceae), inclusive em Maytenus aquifolium Martius, uma das espécies conhecidas no Brasil como “espinheira santa”. Com o objetivo de dispor de um método analítico útil na avaliação da qualidade de medicamentos fitoterápicos de “espinheira san...

A LC/MS method for the analysis of the highly polar anti-diabetic drug metformin in plasma samples is compared to an ion-pair HPLC method with UV detection. Both methods showed good linearity in the concentration range of 50 to 2000 ng/mL, good precision and accuracy and similar sensitivity. The LC-MS method has the advantage of a simpler and faster preparation procedure, shorter analytical tim...

A high-performance liquid chromatography/mass spectrometry (HPLC/MS) method is developed for trace determination of glycols (ethylene glycol, 1,2- and 1,3-propylene glycols, and 2,3-butylene glycol) in water after derivatization with benzoyl chloride. Benzoyl esters of glycols are separated by microcolumn reversed-phase HPLC. Sensitivity and linearity of UV detection at 237 nm is compared with ...

This paper reports the development of an ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC?MS/MS) method to determine eight banned dyes (Sudan I-IV, Sudan Orange, Red 7B, Para Red, Rhodamine B) in turmeric, curry, and chili products. For this purpose, feasibility electrospray (ESI), atmospheric pressure chemical ionization (APCI) photoionization (APPI) for these compo...

A simple and sensitive high performance liquid chromatographic (HPLC) method was developed for quantification of lacidipine in human plasma. Felodipine was used as an internal standard (IS). The present method used protein precipitating extraction of lacidipine from plasma. Separation was carried out on reversedphase c18 column (250 mm × 4.6 mm, 5μ) and the column effluent was monitored by UV d...

Analysis of caffeine and its metabolites is of interest with respect to caffeine exposure, for kinetic and metabolism studies and for opportunistic in vivo estimation of drug metabolizing enzyme activity in humans and animals. For the latter, analysis is usually done by high-performance liquid chromatography (HPLC) with UV detection. However, this method is close to the detection limit for cert...

Methods for the isolation of lipophilic pigments from crude extracts of plant materials (spinach and sweet corn) by high-speed counter-current chromatography (HSCCC) were developed. Particular attention was given to (all-E)-lutein and (all-E)-zeaxanthin. However, the concomitant pigments neoxanthin, violaxanthin and beta-carotene as well as chlorophylls a and b were also considered. Furthermore...