Farklı analitik teknikler kullanılarak organik ve inorganik analitlerin eser düzeyde tayinleri
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Tarih
2021
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Çanakkale Onsekiz Mart Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Hem organik hem de inorganik analitlerin eser seviyelerde tayinlerinin yüksek doğruluk ve duyarlılıkta gerçekleştirilmesi, insan sağlığına ve çevreye etkilerinin etkin bir biçimde irdelenmesi adına büyük önem arz etmektedir. Son yıllarda, analitik kimyada bu amaçla sürdürülen çalışmalara ilgi artmaktadır. Yalnız hassas ve kesin tayin değil, kullanılan yöntemin özellikleri de oldukça önemlidir. Kullanılan yöntemlerin toksik kimyasal kullanımını ve atık sorununu en aza indirerek çevre dostu bir yaklaşım göstermesi, kolay uygulanabilir, ekonomik olması, tekrarlanabilir ve kesin sonuçlar ortaya koyması da bir yöntemden beklenen özellikleri oluşturmaktadır. Bu çalışmada, organik ve inorganik analitlerin belirtilen özelliklere uygun bir yöntem kullanılarak tayinini gerçekleştirmek amacıyla özgün ve seçici yöntemler geliştirilmiştir. Çalışmada, kalem grafit elektrot (pencil grafite electrode, PGE) üzerine öncelikle -1,0 V da 120s kronoamperometri ile cıva (Hg) ve bizmut (Bi) filmi biriktirilmiş daha sonra ise 0,10 M asetat tampon çözeltisinde (pH 4,5) anodik sıyırma voltammetrisi yöntemi (anodic stripping voltammetry, ASV) ile kadmiyum tayini gerçekleştirilmiştir. Anodik sıyırma voltammetrisinin verimini etkileyen analitik parametreler optimize edilmiştir. Optimize edilen analitik parametrelerden kademe potansiyeli (Estep), puls genliği, puls zamanı, biriktirme süresi ve biriktirme potansiyeli aırasıyla 5,0 mV, 125 mV, 5,0 ms, 120 s ve -1,0 V olarak elde edilmiştir. Optimize edilen koşullarda kalibrasyon çalışmaları gerçekleştirilmiş ve elde edilen doğrusal kalibrasyon aralığı 0,25-15 µg L-1 olarak bulunmuştur. Kalibrasyon çalışmalarından sonra analitlere dağıtıcı sıvı-sıvı mikroekstraksiyon (dispersive liquid-liquid microextraction, DLLME) ve manyetik nanopartikül esaslı dağıtıcı katı faz mikroekstraksiyon (magnetic nanoparticle based dispersive solid phase microextraction, MNP-DSPME) uygulanarak daha düşük miktarlarda kadmiyum tayini gerçekleştirilmeye çalışılmıştır. Geleneksel ASV yöntemi ile karşılaştırıldığında geliştirilen MNP-DSPME kullanılarak analit duyarlığında yaklaşık 10 katlık bir iyileştirme sağlanmıştır. Ayrıca kadmiyum tayini için geliştirilen yöntemin seçiciliğine iyonik girişim etkileri de incelenmiştir. Yöntemin gerçek örneklere uygulanabilirliği ve doğruluğu, musluk suyu örneklerine matriks eşleştirme esaslı geri kazanım çalışmaları uygulanarak test edilmiştir. Elde edilen yüksek yüzde geri kazanım sonuçları ile (92-98%), geliştirilen yöntemin gerçek örneklerde uygulanması ile analit tayininde kesin ve doğru sonuçlar elde edileceği gösterilmiştir. Tez çalışmasının ikinci kısmında, beş endokrin bozucu kimyasalın (EDC) (atrazin, penkonazol, fluoksetin, di-n-oktilfitalat ve 4-tert oktifenol) yüksek hassasiyet ve doğrulukta eşzamanlı tayini, ikili çözücü sistemli dağıtıcı sıvı-sıvı mikroekstraksiyon (binary solvent dispesive liquid-liquid microextraction, BS-DLLME) ile kombine edilmiş Gaz Kromatografisi-Alevli İyonlaşma Dedektörü (gas chromatography flame ionization detector, GC-FID) kullanılarak gerçekleştirilmiştir. Optimum ikili çözücü ve dağıtıcı çözücü miktarını belirlemek için deneysel tasarım kullanılmıştır. Bu parametrelerin ana etkileri varyans analizi (ANOVA) kullanılarak değerlendirilmiştir. Tüm analitler için geniş konsantrasyon aralığında en düşük kalibrasyon konsantrasyonlarının altı tekrarlı okuması ile iyi bir doğrusallık ve yüksek hassasiyet (% RSD <10.0) gözlenmiştir. Geliştirilen yöntem ile analitler için GC-FID sistemine ait tayin gücünde 12 - 164 kat arasında artış tespit edilmiştir. Yöntemin doğruluğu ve uygulanabilirliği, kuyu suyu ve hastane atık su numunelerinde 50 ve 100 µg L-1 derişimlerde test edilmiştir. Elde edilen geri kazanım sonuçları % 90,8 - 112,9 arasında değişmektedir. Bu sonuçlar, geliştirilen analitik yöntemin atık su numunesi gibi kompleks matrikslerde analitlerin yüksek doğruluk ve duyarlılıkta tayininde kullanılabileceğini göstermektedir.
Determination of both organic and inorganic analytes at trace levels with high accuracy and sensitivity is of great importance in order to effectively examine their effects on human health and environment. In recent years, there has been an increasing interest in studies conducted for this purpose in analytical chemistry. Not only the precise and accurate determination, but also the characteristics of the method used are very important. The characteristics expected from a method are that the methods used show an environmentally friendly approach by minimizing the use of toxic chemicals and waste problems, being easily applicable and economical, and revealing repeatable and precise results. In this study, specific and selective methods have been developed for the determination of organic and inorganic analytes using a method suitable for their specified properties. In the study, mercury (Hg) and bismuth (Bi) film was deposited on pencil graphite electrode (pencil graphite electrode, PGE) with chronoamperometry at -1,0 V for 120 seconds, then cadmium was determined in 0.10 M acetate buffer solution (pH 4.5) by anodic stripping voltammetry method (anodic stripping voltammetry, ASV). Analytical parameters affecting the efficiency of anodic stripping voltammetry have been optimized. Optimum parameters for the step potential (Estep), pulse amplitude, pulse time, accumulation time and accumulation potential were obtained as 5.0 mV, 125 mV, 5.0 ms, 120 s and -1.0 V, respectively. Calibration studies were carried out under optimized conditions. The linear calibration range obtained was found to be 0.25-15 µg L-1. After the calibration studies, trace amount of cadmium was tried to be determined by applying dispersive liquid-liquid microextraction (DLLME) and magnetic nanoparticle based dispersive solid phase microextraction (MNP-DSPME). Using MNP-DSPME method, approximately 10 time improvement in detection power in comparison to the traditional ASV method was obtained. In addition, the effects of ionic interference on the selectivity of the method developed for cadmium determination were also examined. Applicability and accuracy of the method in real samples were tested by applying matrix matching based recovery studies in tap water samples. With the high percentage recovery results obtained (92-98%), it has been shown that precise and accurate results can be obtained in analyte determination by applying the developed method to real samples with complex matrixes. In the second part of the thesis, the simultaneous determination of five endocrine disrupting chemicals (EDC) (atrazine, penconazole, fluoxetine, di-n-octylphthalate and 4-tert octiphenol) with high sensitivity and accuracy was performed by using a binary solvent dispersive liquid-liquid microextraction method (BS-DLLME) combined with Gas Chromatography-Flame Ionization Detector (GC-FID). Experimental design was used to determine the optimum amount of binary solvent and dispersant solvent. The main effects of these parameters were evaluated using analysis of variance (ANOVA). Good linearity and high precision (RSD <10.0%) were observed for all analytes with six replicate measurements of the lowest calibration concentrations across the wide concentration range. With the developed method, an increase between 12-164 times has been detected in the detection power of the GC-FID system. The accuracy and applicability of the developed method were tested in well water and hospital wastewater samples at the concentrations of 50 and 100 µg L-1. The recovery results obtained vary between 90.8-112.9%. These results show that the developed analytical method can be used in the determination of analytes with high accuracy and sensitivity in complex matrices such as wastewater samples.
Determination of both organic and inorganic analytes at trace levels with high accuracy and sensitivity is of great importance in order to effectively examine their effects on human health and environment. In recent years, there has been an increasing interest in studies conducted for this purpose in analytical chemistry. Not only the precise and accurate determination, but also the characteristics of the method used are very important. The characteristics expected from a method are that the methods used show an environmentally friendly approach by minimizing the use of toxic chemicals and waste problems, being easily applicable and economical, and revealing repeatable and precise results. In this study, specific and selective methods have been developed for the determination of organic and inorganic analytes using a method suitable for their specified properties. In the study, mercury (Hg) and bismuth (Bi) film was deposited on pencil graphite electrode (pencil graphite electrode, PGE) with chronoamperometry at -1,0 V for 120 seconds, then cadmium was determined in 0.10 M acetate buffer solution (pH 4.5) by anodic stripping voltammetry method (anodic stripping voltammetry, ASV). Analytical parameters affecting the efficiency of anodic stripping voltammetry have been optimized. Optimum parameters for the step potential (Estep), pulse amplitude, pulse time, accumulation time and accumulation potential were obtained as 5.0 mV, 125 mV, 5.0 ms, 120 s and -1.0 V, respectively. Calibration studies were carried out under optimized conditions. The linear calibration range obtained was found to be 0.25-15 µg L-1. After the calibration studies, trace amount of cadmium was tried to be determined by applying dispersive liquid-liquid microextraction (DLLME) and magnetic nanoparticle based dispersive solid phase microextraction (MNP-DSPME). Using MNP-DSPME method, approximately 10 time improvement in detection power in comparison to the traditional ASV method was obtained. In addition, the effects of ionic interference on the selectivity of the method developed for cadmium determination were also examined. Applicability and accuracy of the method in real samples were tested by applying matrix matching based recovery studies in tap water samples. With the high percentage recovery results obtained (92-98%), it has been shown that precise and accurate results can be obtained in analyte determination by applying the developed method to real samples with complex matrixes. In the second part of the thesis, the simultaneous determination of five endocrine disrupting chemicals (EDC) (atrazine, penconazole, fluoxetine, di-n-octylphthalate and 4-tert octiphenol) with high sensitivity and accuracy was performed by using a binary solvent dispersive liquid-liquid microextraction method (BS-DLLME) combined with Gas Chromatography-Flame Ionization Detector (GC-FID). Experimental design was used to determine the optimum amount of binary solvent and dispersant solvent. The main effects of these parameters were evaluated using analysis of variance (ANOVA). Good linearity and high precision (RSD <10.0%) were observed for all analytes with six replicate measurements of the lowest calibration concentrations across the wide concentration range. With the developed method, an increase between 12-164 times has been detected in the detection power of the GC-FID system. The accuracy and applicability of the developed method were tested in well water and hospital wastewater samples at the concentrations of 50 and 100 µg L-1. The recovery results obtained vary between 90.8-112.9%. These results show that the developed analytical method can be used in the determination of analytes with high accuracy and sensitivity in complex matrices such as wastewater samples.
Açıklama
Lisansüstü Eğitim Enstitüsü, Kimya Ana Bilim Dalı
Anahtar Kelimeler
Kimya, Chemistry
