الفهرس 
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Abstract
Chapter I
Comprises an introduction to explain the important concepts, classification
of ion selective electrodes (ISEs) and their applications in variety of fields.
Also explains the principles of the flow injection analysis (FIA),
Dispersion, Detection and their applications.
Chapter II
Describes the construction of the Risperidone (RISH+
) selective electrode
, based on PVC matrix membrane containing RISH+
-tetraphenylborate ion
pair as the electroactive component and DBP and O-NPOE as plasticizers.
The electrodes exhibit near Nernstian response to RISH+
over the
concentration range 1x10-5
to 10-2 mol L-1
and detection limit of 2.1x10-6
and 3.2x10-6 molL-1
for DBP and ONPOE membrane based electrodes,
respectively. The electrodes offer many advantages that include; long
lifetime (1.5 months), excellent stability and reproducibility, fast response
time ( <15 s), high thermal stability (isothermal coefficient 0.34 mV/°C)
and superior selectivity for RISH+
over a large number of inorganic and
organic substances. The flow injection technique offers a sampling
frequency of about ~60 samples h-1
. The electrode was successfully used
as indicator electrode in the potentiometric titration of RIS versus
tetraphenylborate (TPB) and in the determination of RIS in pharmaceutical
preparations applying both batch and flow injection techniques. Average
recoveries of 99.63 ± 0.6 and 99.4 ± 2.3 were obtained for Sigmadone and
Psychodal tablets, respectively. The results are comparable with those
obtained with a modified HPLC method.
iv
Chapter III
Solid contact potentiometic sensors based on heptakis (2,3,6-tri-omethyl)-β-CD
were fabricated for flow potentiometric determination of
risperidone (RIS). Electrode matrices composition were optimized
referring to the effect of type and content of the sensing ionohore, anionic
sites and plasticizer. Silver and graphite coated wire electrodes
incorporated with heptakis (2, 3, 6-tri-o-methyl) β-CD as sensing
ionophore, potassium tetrakis (4-florophenyl) borate (KTFPB) as anionic
site and o-nitrophenyloctyl ether (o-NPOE) as electrode plasticizer
showed the best electroanalytical performances. The fabricated electrodes
worked satisfactorily in the concentration range from 5×10-6
to 10-2 mol L-
1 with Nernstian compliance of 59.9 ± 0.7 mV decade-1 of detection limit
1x10-6 mol L-1
and response time of 5s. The developed sensors possessed
improved selectivity, towards risperidone. The sensors have been
successfully applied for the potentiometric determination of RIS in
pharmaceutical preparations under both flow injection analysis (FIA) and
potentiometric titration.
Chapter IV
A simple, rapid and sensitive method for the spectrophotometric
determination of risperidone (RIS) in pure and true solutions has been
developed. The proposed method is based on the charge–transfer
reactions of risperidone as electron donors, with 7,7,8,8,-tetracyanoquinodimethane(TCNQ),2,3-dichloro-5,6-dicyano-1,4-
benzoquinone (DDQ), tetracyanoethylene (TCNE) and chloranilic
acid(CA) as π-acceptors to give colored complexes. The experimental
conditions such as reagent concentration, reaction solvent, temperature
v
and time have been optimized to achieve the highest sensitivity. Beer’s
law is obeyed over the concentration ranges of 8 – 150, 25 – 250, 5 – 70
and 10 – 110 µgml-1
risperidone using DDQ, CA, TCNE and TCNQ
respectively, with corresponding correlation coefficients of 0.9995,
0.9993, 0.9990 & 0.9997 and detection limits of 3.62, 8.66, 1.93 and
2.85 µgml-1
for the reagents in the same order.
Key words:
Risperidone, Sigmadone, Psychodal, Risdal, Ion selective Electrode,
Coated Wire , PVC Membrane, Flow Injection Analysis,
Spectrophotometric Determination, charge Transfer Complex.