Assay
Standard stock solution
Dissolve 570.0mg of sodium chloride,previously dried at 105

for 2hours,in 100mLof water,transfer to a 1000-mLvolumetric flask,dilute with water to volume,and mix.Each mLof this solution contains 224µg of sodium,equivalent to 800µg of anhydrous sodium acetate.
Standard preparations
Transfer to each of four 100-mLvolumetric flasks 10mLof a nonionic wetting agent (1in 500).Dilute the contents of one of the flasks with water to volume to provide a blank.To the remaining flasks add,respectively,5.0,10.0,and 15.0mLof Standard stock solution,dilute with water to volume,and mix.
Assay preparation
Transfer an accurately measured volume of Injection,equivalent to about 800mg of anhydrous sodium acetate,to a 1000-mLvolumetric flask,dilute with water to volume,and mix.Pipet 10mLof this solution into a 100-mLvolumetric flask containing 10mLof a nonionic wetting agent (1in 500),dilute with water to volume,and mix.
Standard graph
Set a flame photometer for maximum transmittance at a wavelength of about 589nm.Adjust the instrument to zero transmittance with the blank,and to 100%transmittance with the most concentrated of the Standard preparations.Read the transmittances of the other Standard preparations,and plot transmittances versus equivalent concentration of sodium acetate.
Procedure
Adjust the instrument as directed under Standard graph,read the transmittance of the Assay preparation,and calculate the sodium acetate content,in mg per mL,of Injection.