One mg of barium sulfate corresponds to 0.137 mg of S or to 0.343 mg of SO3.
The percentage S content of the fertiliser is obtained as follows:
No math image to display
No math image to display
Where:
w = the mass of the barium sulfate precipitate in milligrams,
v1 = the volume of the extraction solution in millilitres,
v2 = the aliquot volume in millilitres,
m = the mass of the test sample in grams.