Optimization of the Schiff-Base Reaction of Acetylacetone with Biogenic Amines

I n this work, optimum conditions for the derivatization reaction of biogenic amines histamine, tyramine, putrecine, tryptamine, phenylethylamine, cadaverine, spermidine and spermine with acetylacetone have been determined. In this reaction, the amount of K2HPO4, reaction time, reagent amount, solvent choice and solvent amount were optimized. As a result of this study, optimum conditions were determined as amount of K2HPO4 2 g, reaction time 20 min, amount of acetylacetone 1 mL, solvent methanol and amount of solvent 10 m

Determination of Calcium and Magnesium in Soils of Samsun-Çarşamba Region by Using Ion-Selective Electrodes

In this study, potentiometric PVC-membrane electrodes were developed with calcium (Ca2+) and magnesium (Mg2+)-selective micro-dimensions with commercially purchased ionophore to determine Ca2+ and Mg2+ ion concentrations in the soil. The potentiometric performance characteristics of the prepared Ca2+ and Mg2+-electrodes were determined and the average potential difference of 23.5 and 27.6 mV was observed for each 10 fold change in concentration versus the parent ion solution in the measurements. The electrodes were found to exhibit linear behavior versus the parent ion solution at a concentration range of 10-1-10-5 mol L-1 and to be highly selective to the parent ion besides the alkali and alkaline earth metal ions. Ca2+ and Mg2+ analyzes of soil samples were performed using potentiometric PVC-membrane ion-selective electrodes prepared in the laboratory. The accuracy of the proposed assay was tested using the AAS technique and the results were found to be in agreement with each other. The results show that the potentiometric PVC-membrane electrodes in the developed Ca2+ and Mg2+-selective micro-dimensions can be used routinely in the determination of these ions in soil samples

Flow injection spectrophotometric determination of iron(III) using diphenylamine-4-sulfonic acid sodium salt

A highly sensitive and very simple spectrophotometric flow-injection analysis (FIA) method for the determination of iron(III) at low concentration levels is presented. The method is based on the measurement of absorbance intensity of the red complex at 410 nm formed by iron(III) and diphenylamine-4-sulfonic acid sodium salt (DPA-4-SA). It is a simple, highly sensitive, fast, and low cost alternative method using the color developing reagent DPA-4-SA in acetate buffer at pH 5.50 and the flow-rate of 1 mL min−1 with the sample throughput of 60 h−1. The method provided a linear determination range between 5 μg L−1 and 200 μg L−1 with the detection limit (3S) of 1 μg L−1 of iron(III) using the injection volume of 20 μL. FIA variables influencing the system performance were optimized. The amount of iron(III) and total iron in river and seawater samples was successfully determined. Repeatability of the measurements was satisfactory at the relative standard deviation of 3.5 % for 5 determinations of 10 μg L−1 iron(III). The accuracy of the method was evaluated using the standard addition method and checked by the analysis of the certified material Std Zn/Al/Cu 43 XZ3F