2.02 2,02,01
Determination of Mean Calibration Factor Fill the standard Sodium Sulphide solution prepared in step no. 1.09,02, in a clean burette, after rinsing the burette 2-3 times with the standard solution. Transfer 1-2-3-4-5-6 ml of standard solution into a series of volumetric flask of 100 ml capacity containing 70 ml zinc acetate solution. Mix the solution :
properly.
2,02,02 Cool the solution to room temperature. Add 2 ml of amine reagent to each
2.02.03
volumetric flask, swirl and add 5 ml conc. Hydrochloric acid mix the solutron. Add 2 ml of reissner solution to each volumetric flask mix the solution properly and make up all the volumetric flask to 100 ml with DM Water, Put the stopper and shake well. Simultaneously, prepare a zeto reference blank by taking 70 ml zinc acetate solution and same quantities of all the reagents. Make up the solution to100 ml with DM Water. Allow 30 minutes for the development of full color in the volumetric flasks. After 30 minutes measure the color intensity of the solution with 10 mm cell in a single beam spectrophotometer at 670 nm. The calibration factors are determined by dividing mg of Hydrogen Sulphide in standard solution taken in each volumetric flask with corresponding absorbance. Find out the mean calibration factor as per following equation. Record the Mean Calibration Factor
F = tnfi i
=1
n
Where,
F = Mean Calibration Factor. tn fi = Sum of allcalibration factors, with ihaving
values from'l to n,
i=1
t't = "r'r" is the total number of observations made with standard solution. SAMPLE MEASUREMENT
a 100m1 Volumetric flask Add 2 ml of amine reagent to volumetric flask, swirl and add 5 ml conc. Hydrochloric acid mix the solution. Add 2 ml of reissner solution to volumetric flask, mix the solution properly and make up the volumetric llask to 100 ml with DM Water. Put the stopper and shake well. Simultaneously, prepare a teto reference blank by taking 70 ml zinc acetate solution and same quantities of allthe reagents. Make up the solution to 100 mlwith DM Water. Allow 30 minutes for the development of full color in the volumetric flasks. After 30 minutes measure the color intensity of the solution with i0 mm cell in a single beam spectrophotometer at 670 nm. Take appropriate amount of sample in
CALCULATION
:
Hydrogen Sulphide
(HzS)
(ppm) = Ax Fx 1000 Sample Volume
Where,
A = Absorbance of Sample Solution. F = Mean Calibration Factor
E