Development and validation of a ultra-high-performance liquid chromatography-UV method for the detection and quantification of erectile dysfunction drugs and some of their analogues found in counterfeit medicines.

Pharmaceutical counterfeiting is a permanently growing problem. Control laboratories are constantly analysing counterfeit medicines. In industrialised countries, one of the main counterfeited class of medicines are erectile dysfunction drugs.

Optimization of micro-HPLC peak focusing for the detection and quantification of low hepcidin concentrations.

Micro-high-performance liquid chromatography is a miniaturized, economic and ecological chromatographic system allowing the use of reduced size chromatographic columns. Coupled with electrospray ionization tandem mass spectrometry, this technique can be used to detect and quantify low concentrations of peptides. In this study, hepcidin was used as the model compound and analysed using octadecylsilica stationary phase by means of a gradient elution mode at a flow rate of 4 μL/min.

Pre-study and in-study validation of a SPE-LC-MS-MS method for the determination of 5-S-cysteinyldopa, a melanoma biomarker, in human plasma.

The incidence of malignant melanoma has increased over the past decades, particularly in Caucasian population. This disease presents defavourable prognosis in terms of survey, especially when detection occurs at the metastatic phase. Reliable analytical methods for biomarker determination are thus an interesting tool in pathology detection and follow-up.

CE-MS method development for peptides analysis, especially hepcidin, an iron metabolism marker.

A method for the resolution of a peptides mixture including hepcidin-25, an iron metabolism marker, was developed by CE-ESI-MS. Several strategies were tested to optimize peptide separation, such as the addition of cyclodextrins or organic solvents in the BGE or the use of coated capillaries. Best results in terms of resolution, symmetry and efficiency were obtained with a BGE made of 500 mM ammonium acetate pH 4.