simultaneous equation mtd

[subathrai]

how to do the calculations for simultaneous equation method for a triple combination

[Don_Hilton]

Could you expand your question a bit? I'm not sure what you mean by "Tripple combination."

[subathrai]

hai Don_Hilton
am doing uv spectrometric analysis on metformin + glimepiridde +rosiglitazone tablets (triple combination)
am planning to determine this by simultaneous equation method
i dont know how to perform the calculations
plz help me

[grzesiek]

seems like normal equation solving
you measure absorbance at three wavelenghts so you got three results - each result is sum of absorbances from three compounds, what you have to know is ratio of absorbances at each wavelength - you must perform UV spectra of known concentrations (or even better make a calibration) of standards

let's say that at 254 you have absorbance ratio of met/glim/ros as 7/2/1

let's say that you measured absorbance is 0.9 so you've got

0.9 = 7x + 2y +1z where x y z are conc of met glim ros

you've got three results (from three wavelengths) and so three equations, now all you have to do is solve it

did you think about maybe derivative spectras??

[Don_Hilton]

Start with the spectra of the three pure components. Use the same solvent for everything.