T. P. Hadjiioannou's research while affiliated with Harokopio University and other places

... Since the analytical signal in kinetic methods of analysis is measured during the course of a reaction, in some cases these methods show certain advantages over conventional equilibrium methods [25]. Thus, kinetic methods of analysis are used for the determination of comparable analytes that react with a common reagent with small differences in their overall free energy and that use reactions with small equilibrium constants or slow reactions. ...

... 134 Further analysis methods are conductometry and potentiometry. 126,149 Structural assignments were achieved by Raman or infrared spectroscopy, and by single-crystal X-ray diffraction. 117−122 Modern analytical protocols were developed by Potthast and Waldvogel using high performance liquid chromatography coupled to a photodiode array (LC-PDA). ...

... Methods for EDTA analysis include polarography [67][68][69], differential pulse polarography (DPP) [70,71], potentiometry [72,73], one-drop square-wave polarography [74], differential pulse anodic stripping voltammetry (DPASV) [75,76], differential pulse cathodic stripping voltammetry (DPCSV) [77] and potentiometric stripping analysis (PSA) [78]. The details of the methods described in literature are presented in Table 3. ...

... Colorimetric methods , based on reactions with a suitable reagent to form a colored compound, followed by photometric or fluorometric determination, are, also, in common use [13]. Alternatively, many electrochemical methods including differential pulse polarography [14], ion-sensitive electrodes [15], conductometric [16], potentiometric [17] [18] and amperometric biosensors [19] [20], have been developed and extensively reviewed for the direct determination of HCHO [21]. ...

... Due to the electroactive nature of NIC, some attempts have also been devoted to develop electrochemical methods for its determination. Several potentiometric methods providing simple design and operation were reported as first electrochemical procedures [21][22][23]. Concerning the use of voltammetric methods with bare electrodes, the major drawback in the determination of NIC arises from its slow electrode kinetics and reaction occurring at very positive (negative) potentials. Thus, the determination is limited by the usable potential range of the electrode material at its anodic end or by overlapping with hydrogen evolution in the cathodic region, often leading to poorly reproducible results. ...

... The reaction proceeds at room temperature and usually takes place under mild conditions. Periodate potentiometric sensors have been reported for determination of different compounds, namely dopamine (Montenegro & Sales, 2000), glycerol (Montenegro & Lima, 1993;Hartofylax & Efstathiou, 1985), 2,3-butanediol (Luca, Reis, Zagatto, & Montenegro, 1998), carbohydrates (Efstathiou & Hadjiioannou, 1977a), and metal ions (Efstathiou & Hadjiioannou, 1977b). The same principal could be applied to ascorbic acid determination, avoiding tedious sampling pre-treating procedures and enhancing the selectivity and quickness of the procedure. ...

... Considering the wide array of applications and effects, picric acid sensing has been a mainstream research in the past decades. Various practices such as chromatography [4], membrane electrode technique [5], and spectrophotometric techniques [6] have been investigated for sensitive and selective detection of picric acid. However, apart from spectrophotometry, other techniques have the drawbacks of real-time sample analysis, costly, and difficulty in handling. ...

... The possibility of using the IET model to describe the ISE response in such systems is demonstrated here by the example of an ISE reversible to salicylate ion. The latter, due to the intramolecular hydrogen bond, is rather hydrophobic, and so the corresponding electrodes have good selectivity and can be used even without the neutral carrier in the membrane [24][25][26][27] (log K Pot values are À 3.22; À 2.49; À 2.25; À 1.52 against Cl À , Br À , benzoate and sulfosalicylate respectively [28]. ...

... Potentiometric [21] and amperometric [22][23][24][25][26] creatine biosensors have also been reported; but, many substantial complications still to be solved such as sensitivity, selectivity, interference effect, reproducibility and sensor stability [27]. Moreover, almost equal concentration of ammonium ions and creatine in biological fluid makes it challenging to quantify creatine precisely by the potentiometric ammonia sensors [28,29]. Amperometric biosensors based on dissolved oxygen are often subtle to the oxygen concentration in the solution, hence always give less accurate results due to the fluctuation of oxygen concentrations [30]. ...

... Alvarez-Casta~ neda et al. Barcoding studies on Mexican plants have mainly focused on evaluating the effectiveness of different DNA regions as markers to distinguish species of seed plants ( Nicolalde-Morej on et al. 2011;Yesson et al. 2011), but several ongoing floristic studies are employing barcodes ( Cabrera et al. 2011;Hern andez-Esquivel et al. 2011). In the case of the medicinal plant species Galphimia glauca, barcodes revealed the existence of three possible species, each with a different chemical profile coincident with the genetic analyses, thus providing an important basis for quality control in therapeutic results ( Sharma et al. 2012). ...