Colorimetric of aspirin determination
Jan 13, 2016
Colorimetric of aspirin determination
antiplatelet effect by inhibiting the production of thromboxane
Acetyl salicylic acid
determine the amount of aspirin in a commercial aspirin product.
used to determine the purity of the aspirin produced in the Microscale Synthesis of Acetylsalicylic Acid lab.
purposes
principle
Exx NaOH
∆
+
FeCL3
Neutralize Why?
Colored complex (violet)Intensity of color direct relationship
with substance concentration
To prevent form
Fe(OH)3
By what? Conc.HCL
Na acetate
Na salicylate
Part I: making standard
procedure
Weight 0.4 g of acetyl salicylic acid (authentic powder)
and put in 100 ml beaker then Add 20 ml distilled water
then add 10 mL of a 0.5N NaOH then heat it on hot plate until
boiling then add 2 drops Ph.ph togive pink
color then add Conc. HCL to neutrlize
Quantitatively transfer the solution to a 250 mL volumetric
flask, and dilute with distilled water to the mark..
Pipet a 5 mL of standard solution to a 100 mL volumetric flask.
then add 5 ml of FeCL3 solution then complete to market with
distilled water.
Label the flask .
Part II: making sample
put one tablet in 100 ml beaker then add 20 ml distilled water by measure then add 5 ml of 0.5 N NaOH .
Heat it on hot plate until boiling the add 2 drops Ph.Ph. To give pink Color then add Conc. HCL to neutralize it .
Filtrate it onto volumetric flask 250 ml by using fitter paper and
Funnel then complete with distilled water (mix well)
Pipette 5ml of sample solution to 100 ml volumetric flask .
Add 5 ml of 5% FeCL3 solution then complete with distilled water To the market. ( mix well).
Label the flask.
Part III: making blank
Put 5 ml of FeCL3 to 100ml volumetric flask then complete
the volume by distilled water
Measure the absorbance at λ max 510 nm
Standard sample blank
Calculation
for standard
concentration of standard is 8 mg/100 ml (mg%)
ᶜᶬ A 1%
For sample
Calculated Conc. Practical Conc.
= 2 mg /100ml (mg%)
1-beers law.
2-matching point.
% recovery
(95-105)
Practicale calculated
According to the result we can say the tablet accepted or rejected
X100