Pemanfaatan turunan Kaliks[4]Resorsinarena sebagai komponen membran elektroda selektif ion perak

RAMADANI, Dr. Dwi Siswanta, M.Eng

2005 | Tesis | S2 Ilmu Kimia

Telah dilakukan karakterisasi terhadap membran selektif ion perak dan aplikasinya untuk elektroda selektif ion (ESI). Dua jenis ionofor turunan kaliks[4]resorsinarena yaitu: tetrakis{N-propildihidrooxazina)- C-metil kaliks[4]resorsinarena dan tetrakis{(dietilamino)metil}-C-metil kaliks[4]resorsinarena digunakan sebagai komponen membran cair elektroda selektif ion, dengan polivinil klorida (PVC) sebagai matriks pendukung, orto-nitrofenil oktileter (o-NPOE) sebagai plasticizer, dan kalium tetrakis(p-klorofenil)borat (KTCPB) sebagai aditif anionik. Karakterisasi terhadap kualitas ESI meliputi: koefisien selektivitas potensiometri, faktor Nernst, trayek pengukuran, dan waktu respon. Koefisien selektivitas potensiometri ditentukan dengan metode larutan terpisah (SSM), faktor Nernst dan trayek pengukuran ditentukan dengan mengukur potensial sel larutan ion perak pada berbagai konsentrasi (10-7 – 10-1 M), dan waktu respon membran ditentukan dengan mengukur potensial sel dalam rentang waktu tertentu pada daerah konsentrasi linear. Hasil penelitian menunjukkan bahwa membran dengan ionofor tetrakis{N-propildihidrooxazina)-C-metil kaliks[4]resorsinarena dan tetrakis {(dietilamino)metil}-C-metil kaliks[4]resorsinarena menghasilkan selektivitas yang lebih tinggi untuk ion perak terhadap ion pengganggu: kalium, amonium, natrium, barium, kalsium, magnesium, timbal, tembaga, kobalt, nikel, dan krom. Masingmasing membran tersebut menunjukkan waktu respon rata-rata yang relatif cepat yaitu 40 dan 45 detik. Membran dengan ionofor tetrakis {N-propildihidrooxazina)-Cmetil kaliks[4]resorsinarena menunjukkan log K pot Ag +, j untuk Na+, Ca2+, Pb2+, Cu2+ dan Cr3+ masing-masing adalah -1,86; -1,97; -1,07; -1,13; dan -1,97, harga faktor Nernst 52 mV perdekade, dan daerah linier pengukuran pada 10-3-10-1 M. Sementara membran dengan ionofor tetrakis{(dietilamino)metil}-C-metil kaliks[4]resorsinarena menunjukkan log K pot Ag +, j untuk Na+, Ca2+, Pb2+, Cu2+ dan Cr3+ masing-masing adalah -2,91; -3.36; -2,06; -1,90; dan -1,77, harga faktor Nernst 22,5 mV perdekade, dan daerah linier pengukuran pada 10-6-10-2 M.

A study on the characterization of silver ion selective electrode had been done. The derivatives of calix[4]resorcinarene i.e.tetrakis(N-propyldihydrooxazine)- C-methyl calix[4]resorcinarene, and tetrakis{(diethylamino)methyl}-C-methyl calix[4]resorcinarene were used as ionophore component of a liquid membrane ion selective electrode (ISE), with polyvinyl chloride (PVC) as a membrane matrix, 2- nitrophenyl octyl ether (o-NPOE) as a plasticizer or membrane solvent, and potassium tetrakis(p-chlorophenyl)borate (KTCPB) as an anionic additive. The quality of the ISEs was characterized by potentiometric selectivity coefficients, Nernst factor, dynamic range of measurement, and response times of the ISEs membranes. The potentiometric selectivity coefficients were evaluated by separated solution method (SSM) with both main and interfering ions concentration of 0.1 M. The Nernst factor and dynamic range of measurement were determined by measuring the potential cell (emf) in 10-7 - 10-1 M concentration of the main ion (silver ion). The response times were evaluated by measuring the potential cell (emf) toward times in the dynamic range concentration. The result of research showed that the membrane using tetrakis(N-propyl dihydrooxazine)-C-methyl calix[4]resorcinarene and tetrakis {(diethylamino) methyl}-C-methyl calix[4]resorcinarene as the ionophore produced better selectivity to silver ion rather than towards interfering ions: potasium, ammonium, sodium, barium, calsium, magnesium, copper, cobalt, lead, nickel and chromium ions. Both of the membranes showed relatively fast response time i.e. 40 and 45 seconds, respectively. The membrane with tetrakis(N-propyldihydrooxazine)-C-methyl calix[4]resorcinarene as ionophore gave log K pot Ag +, j for Na+, Ca2+, Pb2+, Cu2+ and Cr3+ of -1.86, -1.97, -1.07, -1.13, and -1.97, respectively, and the value of Nernst factor was 52 mV/decade, and the dynamic ranges was 10-3-10-1 M. On the other hand, the membrane with tetrakis{(diethylamino)methyl}-C-methyl calix[4]resorcinarene as the ionophore showed log K pot Ag +, j for Na+, Ca2+, Pb2+, Cu2+ and Cr3+ of -2.91, -3.36, -2.06, -1.90, and -1.77, respectively, the value of Nernst factor was 22.5 mV/decade, and the dynamic ranges was 10-6-10-2 M.

Kata Kunci : Elektroda Seleksi Ion,Kaliks[4]Resorsinarena, calix[4]resorcinarene, membrane, ion selective electrode, and silver