Perez, F.F. and Fraga, F., 1987. A precise and rapid analytical procedure for alkalinity determination. Mar. Chem., 21: 169-182. A potentiometric analytical method is proposed for the determination of the alkalinity of seawater. The precision is 0.1% and each determination takes 3 min. The technique is very easy to use, even on board ship since it is carried out in open flasks. A polynomial equ...

The acid dissociation constants of the hydroxyl groups in 25, 26, 27, 28-tetrahydroxy-5, 11, 17, 23-tetrasulphonic-calix[4]arene (SC4) were determined at 25οC by a combination of potentiometric and spectrophotometric titration method. The first and second acid dissociation constants (pKa1, pKa2) were found to be 3.19 and 12.1, which demonstrated pKa shift due to intramolecular hydrogen bonding ...

The acid-base equilibrium of lorazepam was studied by means of potentiometry andmultiwavelengths spectrophotometry. The stoichiometric equilibrium constants were determinedat 25 °C and constant ionic strength 0.1 mol L-1 (NaCl). The acidity constants pK1=1.58±0.05and pK2=11.67±0.07 were found by potentiometry, and pK1=1.54±0.02 and pK2=11.61±0.03 bymulti-wavelengths spectrophotometry. Potentiom...

The mathematical model of steady state mono-layer potentiometric biosensor is studied and the model is based on nonstationary diffusion equations containing a non-linear term related to Michaelis-Menten kinetics of the enzymatic reaction. This paper presents a numerical method based on Legendre wavelets operational matrix method. These results are compared with available limiting case results a...

In this study, a potentiometric sensor composed of palm shell activated carbon modified with trioctylmethylammonium thiosalicylate (TOMATS) was used for the potentiometric determination of mercury ions in water samples. The proposed potentiometric sensor has good operating characteristics towards Hg (II), including a relatively high selectivity; a Nernstian response to Hg (II) ions in a concent...

Potentiometric sensor based on commercial pencil graphite electrodes coated with polyaniline (PAni) composite with Eosin Y (EY) termed as PGE/PAni-EY have been developed for potentiometric determination of silver ion. The electrode exhibited linear response with Nernstian slope of 57.6±0.8 mV per decade within the range of 1.0×10 to 1.0×10 M with limit of detection 6.5×10 M silver ion. Fast and...

The potentiometric response properties of ammonium-, carbonate-, and proton-selective electrodes prepared by incorporating appropriate neutral carriers within novel asymmetric cellulose acetate membranes are reported. The membranes are formed by first casting a thin layer of cellulose triacetate without carrier, hydrolyzing one side of this film with base, and then on the other side casting a s...

A robust voltammetric method has been developed and validated for the determination of Fe(II) and Fe(III) in pharmaceutical iron polysaccharidic complexes. Undesirable low molecular weight iron complexes, at concentration about 3% in the pharmaceutical formulation, can be easily determined with good accuracy and precision. This methodology can be proposed as a viable, environmentally sustainabl...

The construction and performance characteristics of new sensitive and selective in situ modified screen printed (ISPE) and carbon paste (ICPE) electrodes for determination of naphazoline hydrochloride (NPZ-HCl) have been developed. The electrodes under investigation show potentiometric response for NPZ-HCl in the concentration range from 7.0×10-7 to 1.0×10-2 M at 25 °C and the electrode respons...

Recent advances in microelectronics and wireless transmission technology have led to the development of various implantable sensors for real-time monitoring of bladder conditions. Although various sensing approaches for monitoring bladder conditions were reported, most such sensors have remained at the laboratory stage due to the existence of vital drawbacks. In the present study, we explored a...