may be diluted quantitatively with water,if necessary,to yield solutions of suitable concentrations adaptable to the linear or working range of the instrument.
Procedure
Concomitantly determine the absorbances of the
Standard preparationsand the
Assay preparationat the zinc emission line of 213.8nm with a suitable atomic absorption spectrophotometer (see
Spectrophotometry and Light-scattering á851ñ)equipped with a zinc hollow-cathode lamp and an airacetylene flame,using water as the blank.Plot the absorbances of the
Standard preparationsversus concentration,in µg per mL,of zinc,and draw the straight line best fitting the three plotted points.From the graph so obtained,determine the concentration,in µg per mL,of zinc in the
Assay preparation.Determine the concentration,in mg per mL,of Zn in the Injection taken by the formula:
5C/V,
in which
Cis the concentration,in µg per mL,of zinc in the
Assay preparation;and
Vis the volume,in mL,of Injection taken.