November 2012

The JNU campus is a microcosm of the Indian nation, drawing students from every nook and corner of the country and from every group and stratum of society.

Applications are invited on the prescribed application form for admission to the Ph.D Programme in the following disciplines

Engineering, Management, Computer Applications, Mathematics, Home Science, Mass Communication, Chemistry, Pharmacy, Library Science

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Post: Pharmacist on Contractual basis

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No of Vacancy as per ORV act: No of Vacancy-:4 (ST-4)

Sree Chitra Tirunal Institute for Medical Sciences & Technology (SCTIMST), Thiruvananthapuram is an Institute of National Importance  established by an Act  of the Indian Parliament  and  under the 2 administrative control of the Department of Science and Technology, Government of India.

About Authors:
Kalpesh Ashara
Registered Pharmacist S.K.R.I.Medicines Centre, Rajkot, Gujarat, India,
M.Pharm Semester-I Student of B.K.Mody Govt.Pharmacy College Rajkot,
Department of Pharmaceutics GTU, Gujarat, India.
kalpeshashara@yahoo.com, kalpeshshr5@gmail.com*

Abstract:
Spectrophotometry is an attractive method for PKa determination in very diluted aqueous solution about 10^-5 to 10^-6M provided that the compound possesses P^H dependent light absorption due to the presence of a chromospheres in proximity to the ionization centers. Traditionally 6 to 8 aliquot solutions of samples in identical concentrations but with different P^H values are prepared & their absorption spectra are registered at single wavelength. This series of solutions can be generated by either preparing the sample in buffer solutions of known P^H or titrating the sample solution e.g. alkalimetry. Then half the absorbance of maximum plotted on graph & interpolated on x-axis that will give value of P^H is Pka  & negative Antilog of that value at base 10 give value of ka i.e. Dissociation Constant (Pka=-logka). This exercise is carrying out in below assignment.