Apsirin determination, Biology

Indirect determination:

By determining the weight of the filler on the dried filter paper you can calculate the weight of aspirin in each tablet:

weight of acetylsalicylic acid (ie total weight of tablets - filler weight)

number of tablets

How does this compare to the manufacturer's statement?

Think about the possible reasons for any differences observed.

2. Direct determination:

Aspirin is acetylsalicylic acid and must be hydrolysed to salicylic acid before it can be assayed. Salicylic acid is a phenol and can be measured directly because it reacts with Trinder's reagent (Fe(NO3)3 in HCl) to give a coloured solution that can be determined in a spectrophotometer at 525nm.

This reaction can be used on the ethanol filtrates to estimate the amount of acetylsalicylic acid in a single tablet.

1. Dilute filtrates 1 and 2 with water to 1 in 100 (otherwise they will be offscale on the spectrophotometer).

2. Place 1ml of the diluted filtrates 1 and 2, the undiluted filtrates 3 and 4, and a blank of 1ml of water into separate labelled glass test tubes.

3. Add 3ml Trinder's reagent and incubate in the 80°C water bath for 15 minutes.

4. Cool the tubes (either in ice or under running cold water) and read the absorbance at 525nm. If your readings are too high or too low you might need to rethink your dilution factors.

5. Use the Beer-Lambert law to calculate the concentration of salicylic acid in your filtrates (don't forget the various dilutions you have made!). 525 = 949 L mol-1 cm-1

6. From these concentrations, use the RMM of acetylsalicylic acid to convert this to a total weight in your filtrates, and hence per tablet.

7. How does this compare to a) the claimed content and b) the indirect determination?

Posted Date: 5/7/2013 4:08:37 AM | Location : United States







Related Discussions:- Apsirin determination, Assignment Help, Ask Question on Apsirin determination, Get Answer, Expert's Help, Apsirin determination Discussions

Write discussion on Apsirin determination
Your posts are moderated
Related Questions
Describe about diagnostic approach for congenital heart disease ? In this section we propose to outline the principles of a diagnostic approach that is applicable to newborns,


Honey comes under the purview of Prevention of Food Adulteration Act (PFA). Due to its limited production and high cost, honey is prone to adulteration by cane sugar, invert sy

Which one of the following kinds of animals are triploblastic? 1. Flat worms 2. Sponges 3. Ctenophores 4. Corals Flat worms

How is the smoothing tendency of cornea functioned? Smoothing tendency: In health and in disease condition the epitheliurm has a strong tendency to smoothen the underlyin

Animal and Plant Cells The internal structural organisation and information related with hereditary characters and metabolic pathways are similar in all eucaryotic cells whethe

How Environmental temperature affect requirement of protein? Environmental temperature: As environmental temperatures rise or fall above or below the range of thermic neutralit

Q. Which type of defense cell do bacteria attract and cause to multiply during the inflammation process? What is the name given to the waste material produced by the inflammation t

Q. What are the main chemical compounds that destroy the ozone layer? The major chemical compounds that destroy the ozone layer are the CFCs, chlorofluorocarbons, or freons, su

Characters of vitamins: Vitamins are organic substances. They are micronutrients and are required in small quantities. They are not synthesised in the body and therefo