Page 19 - PC 101 practical notes 24-25..

MANSOURA NATIONAL UNIVERSIY
PHARM D- CLINICAL PHARMACY LEVEL I PHARM. ANAL. CHEM. I (PC 101)

Steps for the determination of a sample using

titration

(3 steps to determine the sample concentration)

1 st Preparation of the standard solution (usually HCl, H 2SO 4 or NaOH) and

standardization of it by titration against a primary standard or a previously

standardized secondary standard & then calculation of the correction

factor (f).
small f

f = Volume of the solution of EXACT normality  1ry or previously standardized 2ry.

Volume of the solution of APPROXIMAT E normality the prepared standard solution

If f = (0.95-1.05):  No correction in the preparation

(i.e. the prepared standard solution is ready for use).

If f (< 0.95) or (> 1.05):  certain correction should be done in the preparation by dilution

or concentration & then (f) is recalculated to ensure that it becomes

0.95-1.05.

2 nd Titration of the sample with the prepared standard solution and

observation of the E.P.

3 rd Calculation of the sample concentration.

N.B. We say:

Titrate …………………… with or against or ≠ ……………………

in the flask in the burette
(Titrant)

19 | P a g e