& Measurement procedure
Calibrate the electrode according to the requirements for the use of pH meter.
Accurately weigh 0.23-0.25g (accurate to 0.0001g) of P-204 sample in a 100mL beaker,
add 50mL of 75% ethanol aqueous solution, and then add a magnetic stirring bead.
The electrode was inserted into the beaker liquid, the stirring was turned on, and after
the pH value shown on the pH meter was stabilized, it was titrated with 0.1 mol/L sodium
hydroxide standard solution. Record the volume of 0.1 mol/L sodium hydroxide standard
solution consumed at this time as V1. Continue titration with 0.1 mol/L sodium hydroxide
standard solution until the appearance of the first jump point. Continue the titration with
0.1 mol/L sodium hydroxide standard solution until the second jump point occurs, and
record the volume of 0.1 mol/L sodium hydroxide standard solution consumed at this point as V2.
Representation and Calculation of Results The content of P-204, monooctyl phosphate
in the sample was calculated according to the following formula.
& In the formula:
C-Concentration of sodium hydroxide standard solution, mol/L;
V1-Volume of sodium hydroxide standard solution consumed during the titration to the first synapse point, mL;
V2-volume of sodium hydroxide standard solution consumed when titrating to the second jump point, mL;
m-Mass of P-204 sample, g;
0.3224-millimolar mass of P-204, g/mmol;
0.2102-millimolar mass of monooctyl phosphate, g/mmol.
