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
What does an anther have on it? The anther is the part of the flower that keeps the pollen. This and the filament both make up the stamen.

Choice of a prophylactic agent An effective prophylactic regimen should be directed against the most likely infecting organisms, but need not eradicate every potential pathogen

Define Categories of Indicators of Malnutrition? The indicators may fall under the following categories: 1. Macro indicators for sector-wide monitoring and evolution, 2.

all about excretion

What are the Maximum Crop Yields   Mitscherlich conducted a large number of experiments with different plants, making use of pots 20 cm in diameter and 20 cm in depth. By addin

PHYSICAL STATE OF PROTOPLASM Several theories have been given about its physical structure - (i )  Granular Theory (Proposed by Altman, Hanstein, 1886) - Granules embed

HUMA N CHROMOSOMES The normal diploid (2N) chromosome number in human being is 46. It was given by T.H. Tjio and A. Levan in 1956. The chromosome complement of a cel

special character of leucosolenia

Explain prevention of endocarditis Many physicians believe that antimicrobial prophylaxis before process that may cause transient bacteremia can stop endocarditis and prostheti

What are the indications of Cardiac Transplantation ? Indication :  Patients in NYHA class IV with heart failure, refractory to medical management caused by end stage corona