A di-2-piridil cetona benzoilhidrazona (DPKBH) é um reagente solúvel em uma série de solventes orgânicos mas pouco solúvel em água. Vem sendo utilizado para a determinação de metais, (principalmente do grupo de transição) como Fe(II), Fe(III), Ni(II), Cu(II), entre outros e como ligante de referência para estudar o comportamento dos íons Fe(II) e Fe(III) em presença de espécies orgânicos encontrados em águas naturais. Com o objetivo de entender melhor as propriedades do DPKBH em meio de etanol, foi necessário determinar as constantes de dissociaçãolionização em diferentes porcentagens desse solvente orgânico (10, 19, 29 e 48 %). Nestas porcentagens de etanol, através de medidas absolutas de pH determinaram-se os pKs do DPKBH utilizando-se a técnica potenciométrica e em 10 e 48 % de etanol através de medidas absolutas de pH associadas às absorbâncias das espécies presentes nos equilíbrios, utilizando-se a técnica espectrofotométrica. Nas devidas porcentagens de etanol, o comportamento do eletrodo foi previamente determinado. Os valores de pK1 3,210; 3,342; 3,398 e 3,360 e de pK2 10,834; 11,013; 11,793 e 11,382 foram obtidos respectivamente para 10, 19, 29 e 48 % de etanol, utilizando-se a técnica potenciométrica. Através da técnica espectrofotométrica os valores de pK1 foram 3,257 e 3,322 e pK2 10,880 e 11,820, em 10 e 48 % de etanol, respectivamente. / The di-2-pyridyl ketone benzoylhydrazone (DPKBH) is a soluble reagent in different organic solvents but slightly soluble in water. It has been used for metal determinations, (mainly transition metals) such as for Fe (II), Fe(III), Ni(II), Cu(II) and also like a reference ligand to study the behavior of Fe(II) and Fe(III) ions in the presence of organic species found in natural waters. So as to better understand the DPKBH properties In ethanol, it was necessary to determine the dissociation/ionization constant in different percentages of ethanol (l0, 19, 29 and 48%). In these ethanol percentages, through absolute pH measurements, pKs of DPKBH could be the found by using the potentiometric technique, and in 10 and 48% of ethanol the pKs of DPKBH were determined with pH measurements associated to absorbance of the species present in the equilibria by using the spectrophotometric technique. In appropiate percentage of ethanol the behavior of the glass electrode was previously determined. The pK1 values 3.210; 3.342; 3.398 and 3.362, and pK2 10.834; 11.013; 11.793 and 11.382 were found for 10,19,29,48 % of ethanol, by using the potentiometric technique. The spectrophotometric technique led to pK1 values 3.257 and 3.322, and the pK2 ones 10.880 and 11. 820 in 10 and 48 % of ethanol respectively.

High-performance electromigration separation methods, capillary zone electrophoresis (CZE) and capillary isoelectric focusing (CIEF), have been applied to physico-chemical characterization of new synthetic low-molecular mass markers of isoelectric points. Amphoteric compounds on the basis of aminomethylnitrophenols, their derivatives and other structurally related substances were analyzed by CZE in a series of background electrolytes in a wide pH range, 1.86 - 11.18. From the measured pH dependencies of effective electrophoretic mobilities of analytes (beforehand corrected to reference temperature of 25 řC), their isoelectric points (pI) were determined. In addition, using the non-linear regression analysis of the above dependencies, acid-base dissociation constants (pKa) of ionogenic groups of selected analytes were calculated. Subsequently, the analytes with sharply defined isoelectric points were analyzed by CIEF. CIEF confirmed applicability of these compounds as markers of isoelectric points for calibration of pH gradient in CIEF in the determination of pI of amphoteric compounds, especially peptides and proteins. The determined pKa values of ionogenic groups in particular compounds will be utilized in the development of new pI markers with desired pI values.

In der Industrie gibt es für Phosphonate zunehmend mehr Anwendungsgebiete. Genutzt werden sie unter anderem bei der Öl- und Erdgasgewinnung, in der Baustoffindustrie und bei der Trinkwassergewinnung. Im Rahmen dieser Arbeit wurden aufgrund ihrer Relevanz für die Phosphonate 1-Hydroxyethan-(1,1-diphosphonsäure) HEDP, Amino-tris(methylenphosphon- säure) ATMP, Ethylendiamintetra-(metylenphosphonsäure) EDTMP und Diethylentriamin-penta(methylenphosphonsäure) DTPMP untersucht. Das Hauptziel dieser Arbeit war es, die Löslichkeitskonstanten von Calciumphosphonaten zu bestimmen. Die Bildung von Calciumphosphonat-Salzen wurde bei verschiedenen Bedingungen durchgeführt. Mit den gefällten und unterschiedlichen Calciumphosphonaten wurden die Löslichkeitsuntersuchungen durchgeführt. Die Gleichgewichtsproben wurden chemisch analysiert, um die Zusammensetzung dieser Verbindungen als Cax . Ly . nH2O zu ermitteln. Die Daten ermöglichten die Berechnung der Löslichkeitsprodukte der verschiedenen Calciumphosphonat-Salze. Die für die Berechnung notwendigen Dissoziations- und Komplexbildungskonstanten wurden ebenfalls in dieser Arbeit experimentell bestimmt. Hierzu wurde die pH-Potentiometrie angewandt. Die hier ermittelten Werte stimmen gut mit den Literaturwerten überein. Für DTPMP wurden die Stabilitätskonstanten der Ca-Komplexe erstmalig bestimmt. Im Fall von ATMP und EDTMP wurden Konstanten für erweitere Dissoziations- und Komplexbildungmodelle ermittelt.

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