Chromatography Forum

Hello all!

I have to analyze salicylic acid, benzoic acid and sorbic acid with HPLC. I have prepared standard solutions with concentrations of 20, 40, 60, 80 and 100 mg/l (all of the three analytes are in the same bottle of 10 ml in each standard).

My sample is fruit juice. My instruction tells me to dilute it properly so the concentration fits the calibration curve.

How do i know how much I dilute my sample? I don't know how much analyte there is.

Short answer: you have to test it.

For a fast screening you can do consecutive 1/2 dilution (1 part sample+1 part diluent), about 10 times covers a range of 1:1024.
Then start analysing with the least concentrated one until your peaks are in the desired range.
Once you know the circa range, you can define your final sample prep procedure.

Thank you your answer is super helpful!