NON-AQUEOUS REVERSED PHASE HPLC WITH LOW-WAVELENGTH UV DETECTION FOR TRIGLYCERIDE ANALYSIS

Glycerides are first separated to classes of triglycerides(TGs), diglycerides(DGs) and monoglycerides(MGs) by normal phase HPLC on silica gel column. Individual triglyceride separation is then achieved by non-aqueous reversed phase(NARP) HPLC on C_(18) column with UV detection at 215nm.

High-performance liquid chromatography utilization of ionic liquids as mobile phase additives for separation and determination of the isomers of amino benzoic acids

For the isomers of amino benzoic acid, including o-, m-, p-amino benzoic acid, the beneficial effects of using the ionic liquid, l-butyl-3-methylimidazolium tetrafluoroborate （[BMIm][BF4]）, as mobile phase additives on retention behavior and separation were investigated. Chromatographic separation of the o-, m-, p-amino benzoic acid was performed on a reversed-phase C18 column by ultraviolet detection at 245 nm. The effects of several chromatographic parameters, concentrations and pH values of [BMIm][BF4] solutions, methanol concentration and length of alkyl chain on different ionic liquids, on the separation and determination of the isomers were evaluated. The optimized chromatographic conditions were established using an aqueous 0.5 mmol/L [BMIm][BF4] solution （pH 3.0）/methanol （40：60, v/v） as mobile phase without need of gradient eiution, with separation of three amino benzoic acids achieved within four min. The calibration curve showed good linearity over the tested range of 2 mg/L to 120 mg/L for the three isomers with a correlation coefficients of 0.9999. The recoveries of the three amino benzoic acids of spiked components were between 99.8% and 100%. The method has been successfully applied to the determination of p-amino benzoic acid in the pharmaceutical, Bromine Mitag Procaine Injection.

A melatonin-based targetable fluorescent probe for screening of tumor cells and real-time imaging of glutathione fluctuations in tumor cells

Glutathione(GSH)is a key maintainer of cellular redox balance and plays an important role in many physiological effects.For example,GSH has been widely implicated in cancer initiation,progression and metastasis.Moreover,the concentrations of GSH in tumor cells can influence drug resistance.Given the serious harmfulness of cancer and the important roles of GSH in cancer,it has great significance to devel-opment probes for screening of tumor cells and real-time monitoring of GSH fluctuations in tumor cells.However,no targetable probe for reversible imaging of GSH in tumor cells has been reported.Herein,we constructed a melatonin-based targetable and reversible fluorescent probe(GR-MT)for screening of tumor cells and real-time imaging of GSH fluctuations in tumor cells.The probe uses coumarin as the skeleton,Michael addition reaction as the reaction mechanism,and melatonin as the targeted groups of tumor cells.The experimental results demonstrate this probe has many advantages including high selec-tivity,satisfactory sensitivity,excellent reversible ability,rapid reaction speed,and outstanding targetabil-ity of tumor cells.Therefore,this study provides a promising tool for tumor cells screening and real-time detection of GSH fluctuations in specific tumor cells.