So far sunscreens separation has been achieved primarily by HPLC or TLC on RP-18 or (less frequently) unmodified silica gel as stationary phase. The conditions of chromatographic separation published so far are not suitable for many combinations of UV filters found commonly in cosmetic products. It is therefore reasonable to seek alternative conditions that would make it possible to separate th...

A new L-glutamide derived internal C=O group containing HPLC stationary phase was synthesized. The L-glutamide lipid was immobilized on to silica surface through aminopropyltrimethoxysilane (APS) linker. The detailed chemical structure of the compounds leading to the final lipid was characterized by melting point measurement, FTIR, H NMR and elemental analysis in each step. Chromatographic prop...

A rapid, reversed-phase "high-performance" liquid-chromatographic separation of the five naturally occurring cyclic ribonucleotides is described. The separation, optimized for the measurement of these compounds in biological samples, is short (25 min), sensitive (50-100 pmol), and requires no sample pre-concentration steps. We also report an alternative isocratic elution mode, optimized for a r...

A sensitive and selective high-performance liquid-chromatographic assay for ibuprofen and its major metabolites in biological fluids is described. To ensure good chromatographic separation the drug and metabolites were run on a gradient elution system and detected with a variable wavelength detector set at 220 nm. A second, more rapid, isocratic system is also described for the detection of onl...