Rismiarti, Zuri (2013) Pembuatan dan Karakterisasi Elektroda Selektif Ion (ESI) Oksalat Tipe Kawat Terlapis Berbasis Kitosan. Magister thesis, Universitas Brawijaya.
Abstract
Sekitar 60-80 % penyebab batu ginjal dalam urin adalah kristal kalsium oksalat. Pengukuran oksalat dalam urin sangat penting untuk mendiagnosa adanya hyperoxalauria dan penderita batu ginjal turunan, beberapa metode dalam penentuan oksalat antara lain: amperometri, spektrofotometri serapan atom. Metoda tersebut memiliki presisi dan akurasi yang tinggi tetapi memerlukan instrumentasi khusus dengan biaya analisis relatif tinggi dan penanganan sampel yang kompleks. Untuk mengatasi kendala tersebut diperlukan metoda alternatif yang sederhana, murah namun memiliki sensitivitas tinggi yaitu metode potensiometri menggunakan elektroda selektif ion (ESI). Elektroda selektif ion oksalat berbasis ionofor kompleks logam-ligan dengan polimer PVC telah dikembangkan secara luas. ESI tersebut bersifat Nernstian tetapi belum diaplikasikan secara langsung dalam sampel urin. Disisi lain, telah dikembangkan suatu sensor berbasis biopolimer kationik alam yaitu kitosan. Penelitian ini bertujuan untuk membuat dan mengkarakterisasi elektroda selektif ion oksalat tipe kawat terlapis berbasis kitosan agar dapat dikembangkan menjadi metode alternatif penentuan oksalat dalam urin. Untuk menghasilkan ESI oksalat dengan karakteristik Nernstian maka dilakukan optimasi kompisisi membran dan waktu prakondisi serta perlu dipelajari pengaruh pH, temepratur dan ion asing untuk mengetahui kinerja ESI. Dalam penelitian ini, larutan Na 2 C 2 O 4 1x10 -8 –1x10 -1 M diukur menggunakan ESI oksalat berbasis kitosan dengan elektroda pembanding Ag/AgCl. Penentuan optimasi komposisi membran menggunakan 3 plasticizer yaitu DOP, DOS dan DBP. Selain itu, dilakukan variasi komposisi membran terdiri dari: kitosan:aliquat336:PVC: plasticizer (% b / b ) dalam pelarut THF (1:3 ( b / v )) yaitu (4:0,5:33,5:62), (4:0,5:39:57), (4:1:33:62), (5:1:31:63). Pengaruh lama prakondisi membran dengan merendam ESI dalam Na 2 C 2 O 4 0,2 M dan variasi lama perendaman adalah 15-105 menit dalam rentang 15 menit. Karakteristik sifat dasar ESI yang diuji meliputi: faktor Nernst, kisaran konsentrasi linier, limit deteksi, waktu respon, usia pemakaian dan keberulangan. Kinerja ESI oksalat dikaji melalui pengaruh pH 3-8; pengaruh ion asing (Cl - , H 2 PO 4 - , SO 4 2- ) menggunakan metode tercampur; pengaruh temperatur (25-50 o C). Metoda ESI divalidasi dengan metoda spektrofotometer serapan atom (SSA) dalam penentuan oksalat urin melalui uji t dengan tingkat kepercayaan 95 %. Hasil penelitian menunjukkan komposisi optimum membran yaitu kitosan:aliquat 336-oksalat:PVC:DBP = 4:1:33:62 dan waktu perendaman optimum adalah 75 menit. ESI oksalat tipe kawat terlapis berbasis kitosan bersifat Nernstian dengan harga faktor Nernst sebesar 29,90 mV/dekade konsentrasi, kisaran konsentrasi pengukuran 1x10 -5 - 1x10 -1 M, batas deteksi 2,56 x10 -6 M, waktu respon 30 detik, dan usia pemakaian selama 42 hari serta memiliki sifat reproducible (% CV) sebesar 1,52 %. Kinerja ESI pada kisaran pH larutan 5-7 dengan pH optimum 5 dan temperatur (T) 25-50 0 C dengan T optimum adalah 25 0 C, urutan selektifitas SO 4 2 -C 2 O 4 2 -H 2 PO 4 - ≈Cl - . Uji validasi menunjukkan tidak berbeda nyata dengan metode SSA sehingga metode potensiometri memungkinkan digunakan sebagai metode alternatif dalam penentuan oksalat dalam urin, dengan % akurasi dan presisi (CV) masing-masing adalah 88,85 dan 4,53.
English Abstract
Kidney stones in urine are approximately 60-80% caused by crystals of calcium oxalate. measurement of oxalate in urine is very important to diagnose hereditary kidney stone and hyperoxalauria. Several determination methods of oxalate are spectrophotometric, amperometric, atomic absorption spectrophotometric. methods have high precision and accuracy but require expensive instrumentation, delicate and expert handling of sample and instrument. Hence potentiometric determination based on ion selective electrodes offer several advantages such as ease of preparation, low cost, simple procedure, and easy instrumentation, no sample destruction, fast response. Determination of oxalate using ion selective electrode, ISE had been developed extensively. developed oxalate ISE were based on ei r metal-ligand complexes ionophore with tube type or natural cationic biopolymer of chitosan. However, coated wire oxalate ISE based on chitosan was expected to be developed as an alternative method for determination of urinary oxalate. Nernstian characteristic of oxalate ISE is achieved by optimization membrane composition and timing preconditions. In addition, it was necessary to study influence of pH, temperature and foreign ions to obtain best performance of ISE. In this study, Na 2 C 2 O 4 1x10 -8 -1x10 -1 M solutions were measured using proposed oxalate ISE based on chitosan with Ag/AgCl reference electrode. Determination of membrane composition optimization was conducted using 3 plasticizers of DOP, DOS and DBP with varia tions of membrane composition consist of : chitosan: aliquat336: PVC: plasticizer (% w / w ) in THF solvent (1:3 ( w / v )). ratio of membrane was 4:0,5:33,5:62, 4:0,5:39:57, 4:1:33:62, 5:1:31:63 and ISE was also preconditioned in Na 2 C 2 O 4 0,2 M and soaking time was varied in range from 15-105 minutes (range 15 minutes). Basic characteristics of ISE include: Nernst factor, linear concentration range, detection limit, response time, life time and reproducibility . In order to improve ISE performance influence of pH (3-8), foreign ions (Cl - , H 2 PO 4 - , SO 4 2- ), and temperature (25-50 °C) were also studied . ISE method was validated by applying proposed ISE to determine urinary oxalate with atomic absorption spectrophotometer (AAS) method by t test at 95 % confidence limit. results showed optimum composition of membrane with ratio of chitosan: aliquat 336: PVC: DBP = 4:1:33:62 and optimum soaking time of 75 minutes. proposed coated wire oxalate ISE characteristics showed Nernstian response, with Nernst factor of ISE 29.90 mV/decade of concentration, linier concentration range of 1x10 -5 - 1x10 -1 M, detection limit of 2.56 x10 -6 M, response time of 30 second, and life time of 42 days with reproducibility (% CV) of 1.52. ISE`s performed worked well under pH range of 5-7 and temperature of 25-50 o C, sequence selectivity of SO 4 2- C 2 O 4 2- H 2 PO 4 - ≈ Cl - . Validation test showed that re was no significant difference (t test) between results obtained from ISE and SSA method, so method may be used as an alternative method for determining urinary oxalate, with % accuracy and precision (CV), respectively 88.85 and 4.53.
| Item Type: | Thesis (Magister) |
|---|---|
| Identification Number: | TES/616.075 47/RIS/p/041308022 |
| Subjects: | 600 Technology (Applied sciences) > 616 Diseases |
| Divisions: | S2/S3 > Magister Matematika, Fakultas MIPA |
| Depositing User: | Endro Setyobudi |
| Date Deposited: | 11 Mar 2014 09:16 |
| Last Modified: | 11 Mar 2014 09:16 |
| URI: | http://repository.ub.ac.id/id/eprint/158247 |
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