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S Simeonov

Publications and source records attributed to S Simeonov.

62 records · Page 4Linked to original sources
PubMedDate not supplied

Purity evaluation of aprotinin by high performance liquid chromatography.

A separation to the baseline isocratic technique has been developed for the evaluation of the purity of aprotinin by internal normalization. The column used was a 30 nm pore diameter butyl-bonded silica stationary phase. An exact relationship was found to give an adequate description of the retention of aprotinin using acetonitrile concentrations of 17-22% and NaClO4 concentrations of 5-50 mmol. It can be used to optimize the mobile phase content for the particular user column and to compensate for possible variations in the retention time of aprotinin, analysed on different batches of butyl-bonded stationary phases.

Acetonitriles↗
PubMedDate not supplied

Experimental models for optimization of insulin separation on reversed phase columns.

Experimentally defined relationships have been found to describe adequately the retention and separation of bovine and porcine insulins as well as their desamido products on reversed phases C4 30 nm and C18 10 nm pore diameter. The equations are valid for a region of initial acetonitrile concentrations from 16 to 31% and gradient rates from 0.04 to 0.60%/min. The peak heights showed an exact non-linear relationship with the time interval between the first and last peak of interest, independent of their retention time. The number of experiments required for obtaining the parametric estimates of the models depends on the particular task, but in all cases is less than eight. The relationships found permit the correct choice to be made in advance both for analysis conditions for a particular column and for different requirements of insulin analysis.

Animals↗