Chromatography Forum

Hi,
I am trying to do a liquid-liquid extraction of sulpiride in urine , by water–chloroform-acetic acid- ternary solvent system. After extraction , UV Spectrophotometric Determination of sulpiride in acetic acid.

So, i tried to work with standard solution of sulpiride to determine the extraction recovery , but i can not find the correct formula, for example if i prepare standard solution of sulpiride 50 mg/l , after extraction the UV Spectrophotometric Determination should be determinated from a calibration curve of standards solution in water or in acetic acid???

And the extraction recovery????

I hope to be clear in my explanacation ???

Thank you

The calibrators should be prepared in the same matrix you will use for the measurement (in this case, presumably acetic acid). You then prepare test solutions in your initial matrix (presumably water), carry out the extraction, and measure. You know how much you put in, how much was measured will tell you the extraction efficiency.

Now comes the hard part; prepare spike solutions in sulpiride-free urine. Again, you know what you put in; how much you measure will tell you the extraction efficiency in urine. If this is different from what you got in water, then you are seeing matrix effects (for which you may have to compensate).

Thank you