Diluent, Standard preparation, and Chromatographic system— Proceed as directed in the Assay under Methylsulfonylmethane.

Assay preparation— Weigh and finely powder not fewer than 20 Tablets. Dissolve an accurately weighed portion of the finely powdered material, equivalent to about 1 Tablet, in Diluent, mix, and sonicate for 15 minutes at 50. Allow to cool to room temperature, dilute with Diluent to volume, and mix. Quantitatively dilute with Diluent to obtain a final concentration of 0.4 mg of methylsulfonylmethane per mL. Transfer about 1 mL of the suspension to a 1.5-mL microcentrifuge tube, and centrifuge for 20 seconds. Use the supernatant.

Procedure— Separately inject equal volumes (about 1 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of methylsulfonylmethane (C2H6O2S) in the portion of Tablets taken by the formula: in which D is the dilution factor; C is the concentration, in mg per mL, of USP Methylsulfonylmethane RS in the Standard preparation; and RU and RS are the peak response ratios of methylsulfonylmethane to di(ethylene glycol) methyl ether obtained from the Assay preparation and the Standard preparation, respectively.