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hi guys
this chromatogram represents related substances in dexamethasone phosphate injection ( free dexamethasone )
what i cant understand peaks number 2 and 3 what are they for ?
the method is :
mobile phase ammonium phosphate buffer : ACN 73:27
column C18
flow rate 1 ml
and the wavelength is 254
the formula of this injection solution contains creatinine ( peak 1 ) methyl paraben ( peak 4 )dexamethasone phosphate ( peak 5 ) free dexamethasone ( peak 6 with low response due to very low concentration ) and finally propyl paraben ( peak 7), can this peaks be for degradants were produced during autoclaving of the solution ? a unique degradant of parabens will be parahydroxy benzoic acid , is there any degradant of the parabens can be produced ?
i have done degradation of dexamethasone phosphate std with the same concentration the sample but i didnt have any peaks like those with the same response by boiling with each of NaOH,HCl or H2O2 or even only boiling
do anyone can help?