الفهرس 
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Abstract
The title of the thesis (potentiometric determination of some compounds and their environmental applications)
Ion-selctive membrane-electrodes (ISEs) are a well-established
electro-analytical technique which used in quantitative analysis.
An ion-selective electrode (ISE), also known as (a specific ion
electrode) is a sensor that converts the activity of a specific ion dissolved in
a solution into an electrical potential, which can be measured by a
voltmeter or pH meter. The voltage is theoretically dependent on the
logarithm of the ionic activity, according to the Nernst equation. The
sensing part of the electrode is usually made as an ion-specific membrane,
along with a reference electrode.
Since the end of the 1960s, ion-selective electrodes have continued
to be an important development in analytical chemistry. Polymer
membrane ion sensors in particular find extensive practical applications,
especially in medicinal, agricultural, environmental and different industrial
analysis.
Ion-selective electrodes are used in a wide variety of applications
for determining the concentrations of various ions in aqueous solutions.
The following is a list of some of the main areas in which ISEs have been
used.
• Pollution monitoring: CN, F, S, Cl, NO3 etc., in effluents, and
natural waters.
• Agriculture: NO3, Cl, NH4, K, Ca, I, CN in soils, plant
material, fertilizers and feedstuffs.
• Food processing: NO3, NO2 in meat preservatives.
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• Salt content of meat, fish, dairy products, fruit juices and
brewing solutions.
• F in drinking water and other drinks.
• Ca in dairy products and beer.
• K in fruit juices and wine making.
• Corrosive effect of NO3 in canned foods.
• Detergent manufacture: Ca, Ba, F for studying effects on
water quality.
• Paper manufacture: S and Cl in pulping and recovery-cycle
liquors.
• Explosives: F, Cl, NO3 in explosive materials and combustion
products.
• Electroplating: F and Cl in etching baths; S in anodizing baths.
• Biomedical laboratories: Ca, K, Cl in body fluids (blood,
plasma, serum and sweat).
• F in skeletal and dental studies.
• Education and Research: Wide range of applications.
ISEs offer several advantages as well size, simplicity of operation
and low cost per sample. Besides, they are ideally suited for onsite analysis.
The thesis consists of three parts:
Part I: Introduction
• How dangerous pollutants especially heavy metals on the
environment, the great concern of society about environmental pollution
especially water pollution, increasing interest in the qualitative and
quantitative determination of specific metal species as result of the growing
awareness of the strong dependence of the heavy metals
Summary
109
• Include a general introduction on ion selective electrode such
as classification, mechanism of response of ion selective electrodes,
measuring range, detection limit, selectivity, slope, response time membrane components of ion-selective electrode, theoretical principles,
and some strategies used in fabrication of ion-selective electrodes toward
main group cations.
• Survey about various analytical techniques which have been
proposed for determinations of copper and cobalt.
Part II: Experimental
Include apparatus, reagents and materials used, preparation of
ionophors, preparation of ion-selective membranes for cobalt and copper
ions, characterization the properties of the prepared electrodes,
environmental applications of the prepared electrodes and comparison the
results with atomic absorption spectroscopic results.
Part III: Result and discussion
Simple and direct potentiometric method for determining Cu2+ is
described based on the use of Cu2+ complex of 4-azocyanoacetamido-mtoludine
antipyrine as ionophore. poly(vinyl chloride), the membrane
containing NaTPB as anionic additive and o-NOPE, DOP and DOS as
plasticizers.
The three prepared electrodes was calibrated by measuring the
e.m.f values after stabilization to ± 0.5 mV in a series of Cu2+ solutions
covering the concentration range 1.0×10−6 M to 1.0×10−2 M Cu2+. The e.m.f
values were plotted on a semi logarithmic paper as a function of Cu2+
concentration. The obtained calibration curve was used for subsequent
determination of the unknown Cu2+ ion samples. The selectivity
coefficients for foreign ions were determined by the separate solution
Summary
110
method (SSM) in which the potential readings (mV) of the two separate
solutions one containing only the Cu2+ ion at the concentration level of 10−3
M and the other containing the interferents ions(10-2 - 10-6 M).
The response time of the proposed electrode was also, tested by
measuring the time required to achieve a 95% steady potential for the test
solutions, when the Cu2+ ions concentration were rapidly increased by one
decade from 1.0×10−6 M to 1.0×10−2 M. The potential readings were
recorded against time (Sec). The lifetime of the investigated Cu2+electrodes
were measured from the response potential to the varying
Cu2+concentration every day for more than 6 weeks.
This electrode has been used as an indicator electrode in
potentiometric titration of Cu2+ ion with EDTA and direct determination of
Cu2+ ion in wastewater of the electroplating industry. The direct
determination of copper ion in wastewater of the electroplating industry
gave results that compare favorably with those obtained by the atomic
absorption spectrophotometric method. The electrodes were successfully
applied for the determination of copper ion.
The Co2+-4-formylazohyrazoaniline antipyrine complex can be
regarded as a carrier for the construction of a novel PVC-based membrane
using DOP and DOS as plasticizers for cobalt detection. The proposed
electrode has good operating characteristics (sensitivity, stability, response
time, detection limit and a wide linear range). It is easy to prepare and use,
this electrode has been used as an indicator electrode in potentiometric
titration of Co2+ ion with EDTA and direct determination of Co2+ ion in real
samples, the direct determination of cobalt ion in tap water and samples
from local rive Nile gave results that compare favorably with those
obtained by the atomic absorption spectrophotometric method. The
electrodes were successfully applied for the determination of cobalt ion.