The problem quoted by you may be regarding to the less concentration of the drug in solution than expected. Its obvious that the solution is absorbing too low than expected.
Re-prepare the solution/s with care not to loose any drop and then re-read it.
Hope it will correct your problem.
Dear Chukwuebuka Egbuna,
You have not made it clear why you said "Instead" ? I agree with
Mr.Vivekanand Chatpalliwar. Did you use a concentration of the drug gave you before
A = 0.535 according to a calibration you yourself made it? Have you performed your experiment exactly as you did before for the same drug, same purity and same concentration with correct blank? Please check every thing, if everything was perfect, then check your instrument with a standard. Wish you success, thank you and Good Luck.
Thank you very much dear researchers for your contributions. I have prepared a fresh sample, this time comparing the paracetamol drug with a primary reference standard but the absorbance still reads between 0.082 to 0.086 which i consider very poor because this same spectrophotometer just 5 days ago as in before reads from 0.530 to 0.540 upwards. This problem is not peculier to paracetamol alone, all other drug samples reads low.
Good morning from India.
In the current problem, if the readings are similarly erratic with fresh solutions, then it can be inferred that the instrument is disturbed meanwhile. Even slight disturbance can cause changes in mirror/gratings alignments. DO call for service engineer.
Dear Chukwuebuka,
What are you using as a blank solution. This should be the same solvent as for your sample/standard solutions. Did you ‘zero’ the spectrophotometer with the blank. Please see the attached document, which may be of use to you.
Kind regards,
Ade Kujore
Marketing
Cecil Instruments Limited
Milton Technical Centre, Cambridge CB24 6AZ
United Kingdom
email:- [email protected]
telephone:- +44 (0) 1223 420821
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Dear Ade,
I think I have not zeroed the spectrophotometer well. I need a step by step guide although I can see some clue from this material.
Thank you so much for sharing this material with me.
Best regards,
Egbuna, C.