While tailing and overloading of basic compounds remain problematic on most RP columns, a new kind of positively charged RP column named XCharge C18 was found to be superior good for the separation of alkaloids in our practical use. In this work, the surface charge property of the XCharge C18 column was evaluated by the retention of NO(3)(-) under different pH values and buffer concentrations. ...

A facile "one-pot" approach to prepare organo-silica hybrid capillary monolithic column with intact mesoporous silica nanoparticle (IMSN) as crosslinker and building block was described. An IMSN crosslinked octadecyl-silica hybrid capillary monolithic column (IMSN-C18 monolithic column) was successfully prepared, and the effects of fabrication conditions (e.g. concentration of intact mesoporous...

Tracheopulmonary intubation is the most common misplacement site for narrow-bore feeding tube and it might be associated with severe pleuro-pulmonary complications. A 38-year-old female with a severe bilateral pneumonia and acute respiratory insufficiency was admitted in the ICU, intubated, and mechanically ventilated. Few hours after the insertion of a narrow-bore feeding tube the patient's ox...

Background An HPLC method employing a post-column derivatization strategy using the cupric reducing antioxidant capacity reagent (CUPRAC reagent) for the determining antioxidants in plant-based materials leverages the separation capability of regular HPLC approaches while allowing for detection specificity for antioxidants. Methods Three different column types, namely core-shell and porous si...

Saponins are widely distributed in the plant kingdom and have been shown to be active components of many medicinal herbs. In this study, a two-dimensional purification method based on reversed-phase liquid chromatography coupled with hydrophilic interaction liquid chromatography was successfully applied to purify saponins from leaves of Panax notoginseng. Nine saponin reference standards were u...

weight-gain and potency enhancing drugs are the most popular herbal products in iran which are easily available via the internet and through illegal markets. the content of some of these popularly purchased products were investigated for the presence of illegal substance like phosphodiesterase inhibitors (pdh-5) and corticosteroids by hplc method. for this study, ten samples of both kind of her...

We developed a packed-column chromatographic procedure capable of simultaneous quantitation of methanol, ethanol, isopropanol, acetone, and ethylene glycol. This method was then updated to a rapid, sensitive, wide-bore capillary method. The packed-column system uses direct injection of 1 microL of Na2WO4/H2SO4-deproteinized serum onto a 1.8 m x 2 mm (i.d.) column packed with 80/100 HayeSep R. A...

Lipopeptides are currently re-emerging as an interesting subgroup in the peptide research field, having historical applications as antibacterial and antifungal agents and new potential applications as antiviral, antitumor, immune-modulating and cell-penetrating compounds. However, due to their specific structure, chromatographic analysis often requires special buffer systems or the use of trifl...