[marutikmv]

How the Cesium is analysed in Drug matrix

[Mansouri]

Assay for calcium

 [NOTE : Concentrations of the Standard preparations and the Assay preparation may be
modified to fit the linear or working range of the atomic absorption spectrophotometer.]

Lanthanum chloride solution : Transfer 17.69 g of lanthanum chloride to a 200-mL volumetric flask, add 100 mL of water, and carefully add 50 mL of hydrochloric acid. Mix, and allow to cool. Dilute with water to volume, and
mix.
Dilute hydrochloric acid: Prepare by mixing 678 mL of hydrochloric acid with sufficient water to make 3000 mL.
Blank solution: Transfer 5.0 mL of Lanthanum chloride solution to a 100-mL volumetric flask, dilute with Dilute
hydrochloric acid to volume, and mix.
Calcium stock solution: Transfer 499.5 mg of primary standard calcium carbonate to a 200-mL volumetric flask,
and add 10 mL of water. Carefully add 5 mL of Dilute hydrochloric acid, and swirl to dissolve the calcium
carbonate. Dilute with water to volume, and mix. This solution contains 1000 mg of calcium (Ca) per mL.
Standard preparations: To three separate 100-mL volumetric flasks, each containing 5.0 mL of Lanthanum
chloride solution, add 1.0, 1.5, and 2.0 mL, respectively, of Calcium stock solution. Dilute the contents of each
flask with Dilute hydrochloric acid to volume, and mix. These three solutions contain 10.0, 15.0, and 20.0 mg,
respectively, of calcium (Ca) per mL.
Assay preparation: Transfer an accurately measured volume of Injection, equivalent to about 20 mg (1 mEq) of
calcium, to a 1000-mL volumetric flask containing 50.0 mL of Lanthanum chloride solution. Dilute the contents of the flask with Dilute hydrochloric acid to volume, and mix.
Procedure: Concomitantly determine the absorbances of the Standard preparations and the Assay preparation at
the calcium emission line at 422.7 nm, with an atomic absorption spectrophotometer, equipped with a calcium hollow-cathode lamp and an air-acetylene flame, using the Blank solution as the blank. Plot the absorbances of the Standard preparations versus concentration, in mg per mL, of calcium, and draw the straight line best fitting the three plotted points. From the graph so obtained, determine the concentration, C, in mg per mL, of calcium in the Assay preparation. Calculate the quantity, in mg, of calcium in each mL of the Injection taken by the formula:

1000(C / V),

in which V is the volume, in mL, of Injection taken to prepare the Assay preparation.