Experiment No. 03- DETERMINATION OF SODIUM AND POTASSIUM BY FLAME PHOTOMETRY

Determination of sodium and potassium by flame photometry

INTRODUCTION

Potassium (K) is the major cation found inside Of Cells. The Proper Level Of Potassium is essential for normal cell function.

An abnormal increase of potassium (hyperkalemia) or decrease of potassium (hypokalemia) can profoundly affect the nervous system and heart , when extreme, can be fatal.

The normal blood potassium level is 3.5-5.0 millimoles/liter (mmol/l).

Sodium (Na) is the major extracellular cation and it plays  role in body fluid distribution. Concentration of sodium ions inside the plasma(extracellular) is 130-145 mmol/l.

higher and lower concentration are referred to as hypernatremia and hyponatremia respectively.

 

Instruments Reagent And Glassware

•1.  Flame Photometer

•2.  Stock Solutions Of Na + And K+, c= 1mg/ ml

• 3.  6 Numbered 100 ml Volumetric Flasks.

•4.   Glass Pipettes ; 1,2,10 ml

•Analytical Procedure :

•

Preparation of standard solutions –

Standard solution are prepared by dilution of stock solutions. Use different glass pipettes and numbered 100ml volumetric flask and prepare the solutions according to the following table:

Flask number	1	2	3	4	5	6
Vol. of pipette to use	1	1	2	10	10	10
Vol. of Na stock solution to pipette	0.5	1	2	4	6	8
Vol. of  K stock solution to pipette	0.5	1	2	4	6	8
Conc. Of Solution  Obtained  (µg/ml)	5	10	20	40	60	80

•Sample preparation –

Test solution is given in 100 ml flask. Fill it up to the mark with distilled water and mix.

•Measurement procedure –

• let the instrument warm up for 5-10 minutes

•Feed distilled water to the instrument.

•Using knobs adjust the indicators to 0 reading.

•Aspirate the most concentrate standard solution ( solution 6) and adjust readout to approximately 90 (on uppermost scale)using the big knobs.

•Aspirate distilled water – the instrument should read 0.

•

•Aspirate standard solutions no.1,2,3,test solution, and then standard 4,5,6.

•

•Record the results.

•Aspirate distilled water for at least 5 minutes to clean the system.

Result and discussion-

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Draw calibration curve for sodium and potassium on a sheet of millimeter-paper. Use concentration as abscissa and instrument readouts as ordinate values.

Find concentration of sodium and potassium ions in test solution from calibration curves