DEVELOPMENT OF SOL-GEL IMMOBILIZED SORBENT FOR CAPILLARY MICROEXTRACTION. PhD thesis, King Fahd University of Petroleum and Minerals.
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Arabic Abstract
هذا العمل يهدف لتطوير مواد ماصّة بتقنية SOL-GEL للاستخلاص الميكروي الشعري. تم تصنيع ثلاثة مركبات مختلفة لهذا الغرض وتتضمن: 1) Urea functionalized-[bis(hydroxyethyl)amine] terminated polydimethylsiloxane (BHEA-BPU). 2) Yttria surfaced-[Bis (hydroxyethyl) amine] terminated polydimethylsiloxanes (BHEA-Y). 3) Germania-based polydimethylsiloxane (PDMS/Ge). تم استعمال المركبين الأول والثاني كطلاء في الاستخلاص الميكروي الشعري، فيما تم استخدام المركب الثالث في الاستخلاص بتقنية Stir-bar Sorptive Extraction. خصائص جميع المواد تم تحديدها باستعمال: 1) X-ray photoelectron spectroscopy. 2) Thermogravimetric analysis. 3) Field emission scanning electron microscope. 4) Energy dispersive X-ray spectrometer. تم استعمال BHEA-BPU and BHEA-Y coated capillaries فيonline extraction و high-performance liquid chromatographic analysisللأميدات، الفينولات، الكحول، الكيتونات، الألدهيدات، والهيدروكربونات الأروماتية المتعددة. أظهر PDMS/Ge based coating تركيز مسبق عالي في Stir bar عند الكشف عن 4-chloro-1-naphthol. أثبتت جميع أجهزة الاستخراج إمكانياتها الممتازة من خلال توفير بيانات موثوقة، قابلة للتكرار، ودقيقة من حيث معامل الاختلاف، حدود الكشف، والعلاقة الخطية. بالإضافة لذلك، يتم توفير تحليل العينات الحقيقية مع استعادة المستخلصات وإعادة التكرار. أظهرت BHEA-BPU coating حساسية عامة ممتازة بالنسبة لمعدلات الكشف المنخفضة(S/N = 3) للحلائل (0.10 ng mL-1 to 14.29 ng mL-1) مع قابلية تكرار مقبولة بمعامل اختلاف أقل من 12.0% (n = 3). كذلك، تم أيضًا اختبار The capillary to capillary reproducibility للتحاليل عن طريق تغيير الحجم. وقد أظهر ذلك معامل اختلاف ممتاز أقل من .(n = 3) 10.0% وبينت BHEA-Y coating حدود كشف تتراوح من 0.18 ng mL-1 لـ 7.35 ng mL-1 (S/N = 3) مع معامل اختلاف بين 0.6% لـ 6.8% .(n = 3) وقد تم الأخذ بالحسبان قابلية تكرار عملية إعداد وطلاء الـ Capillary باستخدام تحليل Capillary to capillary extraction مع معامل اختلاف مقبول بين 4.1% لـ .9.9% وأبدت PDMS/Ge coated stir bars قابلية تكرار جيدة بـ 1.7% (n = 3)لدفعة واحدة و3.5% (n = 3) لدفعات مختلفة. تحت الظروف التجريبية المحسنة، أظهرت المنهجية علاقة خطية في نطاق 0.4-800 ng mL-1 و R2 = 0.9992 وحد كشف (S/N=3) بمقدار 0.034 ng mL-1. تم استخراج 4-chloro-1-naphthol من مياه الصرف الصحي، مياه المسابح، والبول البشري وأظهرت استردادات نسبية بين 87.1 - 97.2% مع معامل اختلاف مقبول بـ 4-11%.
English Abstract
This work is to develop sol-gel based sorbent materials for capillary microextraction. Three sorbent materials were synthesized including urea functionalized-[bis(hydroxyethyl)amine] terminated polydimethylsiloxane (BHEA-BPU), yttria surfaced-[Bis (hydroxyethyl) amine] terminated polydimethylsiloxanes (BHEA-Y), and germania-based polydimethylsiloxane (PDMS/Ge). The former two coatings were used for capillary microextraction and germania based coating used for stir-bar sorptive extraction. The characterization all the materials was successfully done by using X-ray photoelectron spectroscopy, thermogravimetric analysis, field emission scanning electron microscope, and energy dispersive X-ray spectrometer. BHEA-BPU and BHEA-Y coated capillaries were used for online extraction and high-performance liquid chromatographic analysis of amides, phenols, alcohols, ketones, aldehydes, and polyaromatic hydrocarbons. The PDMS/Ge based coating on the stir bar presented high preconcentration for the detection of 4-chloro-1-naphthol. All the extraction devices have proved their excellent potential by providing reliable, reproducible, and sensitive data in-terms of %RSD, LODs, and linearity. Moreover, real sample analysis is provided along-with extraction recovery and reproducibility. BHEA-BPU coating showed excellent overall sensitivity in terms of lower detection limits (S/N = 3) for the analytes (0.10 ng mL-1 to 14.29 ng mL-1) with acceptable reproducibility that is less than 12.0 %RSD (n = 3). Moreover, the capillary to capillary reproducibility of the analysis was also tested by changing the capillary of the same size. This provided excellent %RSD of less than 10.0 % (n = 3). BHEA-Y coating produced detection limits ranging from 0.18 ng mL-1 to 7.35 ng mL-1 (S/N = 3) with relative standard deviation (RSD) between 0.6% to 6.8% (n=3). The capillary preparation and coating method reproducibility was also considered by capillary to capillary extraction analysis with acceptable RSD between 4.1% to 9.9%. The PDMS/Ge coated stir bars showed a good preparation reproducibility of 1.7% (n=3) for one batch and 3.5% (n=3) for different batches. Under optimized experimental conditions, the method showed linearity in the range of 0.4-800 ng mL-1 with R2 = 0.9992 and limit of detection (S/N=3) as 0.034 ng mL-1. 4-chloro-1-naphthol was also extracted from wastewater, pool water, and human urine and showed relative recoveries between 87.1 - 97.2% with acceptable relative standard deviation i.e. 4-11%.
Item Type: | Thesis (PhD) |
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Subjects: | Chemistry |
Department: | College of Chemicals and Materials > Chemistry |
Committee Advisor: | Alhooshani, Khalid |
Committee Co-Advisor: | Abulkibash, Abdallah |
Committee Members: | Chanbasha, Basheer and Shaikh, Asrof Ali and Isab, Anvarhusein |
Depositing User: | SHEHZADA SAJID JILLANI (g201207000) |
Date Deposited: | 16 Oct 2018 10:07 |
Last Modified: | 31 Dec 2020 07:06 |
URI: | http://eprints.kfupm.edu.sa/id/eprint/140824 |