Details

The HI84432-55 is a 100 mL bottle of pump calibration standard solution that is used for determination of acidity in fruit juice.

Fruit juice acidity is determined by neutralization of all available hydrogen ions present in the sample with a strong base solution:

H⁺ + OH^- → H₂O

The endpoint of an acid base titration corresponds to the complete neutralization of the acids present. The predominant acids present depend on the type of fruit being tested and include citric acid, tartaric acid, and malic acid. The titration to a fixed pH endpoint gives the result of all substances present that have an acidic nature including: free hydrogen ions, organic acids, and acid salts. Titratable acidity is expressed as g/100 mL (%w/v) of the predominant acid.

For precise results it is very important to know the sample volume, titrant volume, and titrant concentration. As the titrant comes pre-standardized, it is important to determine the amount of titrant delivered by the dosing pump. This determination is done by the pump calibration procedure. In this procedure the analysis of a known volume of a known solution (HI84432-55) is titrated with the appropriate titrant to the pH endpoint that is potentiometrically determined by the HI1131B pH electrode.  The pump calibration procedure should be performed anytime the titrant, syringe, tubing or pH electrode is replaced. It is recommended to do a pump calibration every time a new set of titrations are to be performed.

Replacement reagents required to operate the HI84432: