Potassium Guaiacolsulfonate
;)
Benzenesulfonic acid,hydroxymethoxy-,monopotassium salt,hemihydrate.
Potassium hydroxymethoxybenzenesulfonate hemihydrate [78247-49-1].
Anhydrous 242.30
»Potassium Guaiacolsulfonate contains not less than 98.0percent and not more than 102.0percent of C7H7KO5S,calculated on the anhydrous basis.
Packaging and storage—
Preserve in well-closed,light-resistant containers.
Identification—
A:
Infrared Absorption á197Mñ:between 7µm and 13µm,previously dried at 105
for 18hours.
for 18hours.
Solution:
50µg per mL,prepared as directed in the Assay.
C:
Asolution (1in 10)responds to the tests for Potassium á191ñ.
Water,Method Iá921ñ:
between 3.0%and 6.0%.
Selenium á291ñ:
0.003%.
Sulfate—
To 10mLof a solution (1in 20)add 5drops of barium chloride TS,and acidify with hydrochloric acid:no turbidity is produced in 1minute.
Heavy metals á231ñ—
Dissolve 1.0g in 1mLof 1Nacetic acid,and dilute with water to 25mL.The limit is 0.002%.
Assay—
Transfer about 250mg of Potassium Guaiacolsulfonate,accurately weighed,to a 500-mLvolumetric flask,dissolve in 400mLof water,dilute with water to volume,and mix.Dilute 10.0mLof this solution with pH7.0phosphate buffer to 100.0mL,and mix.Concomitantly determine the absorbances of this solution and a Standard solution of USP Potassium Guaiacolsulfonate RSin the same medium,having a known concentration of about 50µg per mL,in 1-cm cells at the wavelength of maximum absorbance at about 279nm,with a suitable spectrophotometer,using a 1in 10mixture of water and pH7.0phosphate buffer as the blank.Calculate the quantity,in mg,of C7H7KO5Sin the Potassium Guaiacolsulfonate taken by the formula:
5C(AU/AS),
in which Cis the concentration,in µg per mL,calculated on the anhydrous basis,of USP Potassium Guaiacolsulfonate RSin the Standard solution,and AUand ASare the absorbances of the preparation under assay and the Standard solution,respectively.
Auxiliary Information—
Staff Liaison:Daniel K.Bempong,Ph.D.,Scientist
Expert Committee:(PA2)Pharmaceutical Analysis 2
USP28–NF23Page 1595
Phone Number:1-301-816-8143