Gülşen Öztürk

Chemical speciation of heavy metals in the Tigris River sediment

Abstract After determination of total heavy metal concentrations in Tigris river sediments, a Tessier sequential extraction technique and a modified form using a microwave heating procedure were applied. Recoveries of total heavy metals from the sediment samples using the microwave and conventional techniques were reasonably comparable, in spite of a big difference in time required. 44–46% of Co, 24–36% of Cu, 69-81 % of Ni, and 55–73% of Zn were found in the residual fraction (i.e. not bioavailable).

Microwave Assisted Transesterification of Maize (Zea Mays L.) Oil as a Biodiesel Fuel

Maize (Zea mays L.) oil is a highly valuable agricultural commodity for the Turkey. Transesterified maize oil has the global better properties because it has the greater monounsaturated content. Biodiesel has been prepared from maize by transesterification of the crude oil under microwave irradiation, with methanol to oil molar ratio of 10:1, in the presence of 1.5% NaOH as catalyst and 5 minutes time, the conversion of maize oil to methyl ester was over 98%. Compared with conventional heating methods, the process using microwaves irradiation proved to be a faster method for alcoholysis of triglycerides with methanol, leading to high yields of biodiesel.

Synthesis of Esters Under Microwave Irradiation Using Heteropoly Acids as Catalysts

A practical and simple technique for synthesis of esters was developed by using heteropoly acid as catalyst under microwave irradiation in the absence of organic solvents. Alcohols were easily and selectively converted to their acetates and benzoates with excellent yields (≥98%), and in very short time (∼5 min), as environmentally benign.

Synthesis of Ferrocenyl Schiff Bases Under Solvent-Free Conditions Using Microwave Irradiation

Abstract Ferrocenyl imines 3a–f were synthesized using solvent-free methods by mixing ferrocene carbaldehyde 1 with amines 2a–f under microwave irradiation. The imines were obtained in good yield in short reaction times.

Solvent-free synthesis of chiral Schiff-base ligands based on ferrocene under microwave irradiation and application to enantioselective nitroaldol (Henry) reaction.

Chiral Schiff-bases 3a-f based on ferrocene were designed and synthesized using solvent-free methods by mixing ferrocene carbaldehyde 1 with amino alcohols and amines 2a-f under microwave irradiation and classical method for the enantioselective nitroaldol (Henry) reaction. The Schiff-bases were obtained in shorter reaction times and improved yield under microwave irradiation method over classical method. The highest enantioselectivity was observed in ligand 3e (95% ee) when CH(2)Cl(2) was used as solvent.

Solvent-Free Synthesis of Nitrilotriacetamide and Diketopiperazines from Nitrilotriacetic Acid under Microwave Irradiation and Their Antimicrobial Activity

Abstract Efficient synthesis of dioxopiperazines‐diketopiperzines (DKPs)‐ and amide from nitrilotriacetic acid (NTA) using microwave irradiation and classical heating were described. All compounds were characterized using 1H NMR, 13C NMR and elemental analysis. Antimicrobial effects of these compounds are also investigated. All tested compounds showed moderate antimicrobial activity.