Tez özetleri Astronomi ve Uzay Bilimleri Anabilim Dalı 2

Cloud Poınt Extractıon Preconcentratıon And Determınatıon Of Ammonıa
Dissolved ammonia is one of the most important pollutants in our environment and the main source of ammonia contamination is farming and agricultural activities. Exposure to high levels of ammonia can cause irritation and serious burns on the skin and in the mouth, throat, lungs, and eyes. At very high levels, ammonia can even cause death. Given its high toxicity and trace level in natural samples, the preconcentration and determination of ammonia has gained significant importance to a number of applications including environmental protection and agriculture sector.
Cloud-point extraction (CPE) is probably the most versatile and simple method for the preconcentration and extraction of hydrophobic species from water. The technique is based on the property of most nonionic surfactants in aqueous solutions to form micelles and become turbid when heated to a temperature known as the cloud point temperature (CPT). The aim of this thesis is to apply cloud point extraction as a preconcentration step for spectrophotometric determination of ammonia in water samples. The proposed method is based on the color reaction of ammonia with o-phthaldialdehyde (OPA) in the presence of sulfite to form isoindole compound and extraction of the formed isoindole derivative using the cloud point extraction technique. The main factors affecting CPE procedure, such as concentration of phthalaldehyde (OPA), NaOH, Na₂SO₃, amount of Triton X-114, equilibrium temperature, and incubation time were investigated and optimized. Under the optimal conditions, the limit of detection (LOD) for ammonia was 2.0 x 10^-6 mol.L^-1, with preconcentration factor (EF) of 20. Calibration curve was linear inthe range of 0.5 – 6.0 x 10^-5 mol.L^-1 , and relative standart deviation was 0.7 % (c = 2.5 x 10^-5 mol.L^-1; n = 5). The proposed method was applied to the determination of trace ammonia in real water samples with satisfactory analytical results.

KAYA Büşra

Danışman : Prof. Dr. Bahri ÜLKÜSEVEN

Anabilim Dalı : Kimya

Programı : Anorganik Kimya

Mezuniyet Yılı : 2014

Tez Savunma Jürisi : Prof. Dr. Bahri ÜLKÜSEVEN

Prof. Dr. Ulvi AVCIATA

Prof. Dr. İrfan KIZILCIKLI

Doç. Dr. Ayşe ERÇAĞ

Doç. Dr. Tülay BAL DEMİRCİ