SINTESIS RESIN POLI-KALIKS[4]ARENA DARI p-t-BUTILFENOL DAN PEMANFAATANNYA SEBAGAI ADSORBEN SERTA ANTIDOTUM KERACUNAN LOGAM BERAT

TRIANA KUSUMANINGSIH, Prof. Drs. Jumina, Ph.D.

2012 | Disertasi | S3 Ilmu Kimia

Telah dilakukan sintesis resin poli-kaliks[4]arena dan pemanfaatannya sebagai adsorben serta antidotum keracunan logam berat. Sintesis resin polikaliks[ 4]arena dilakukan dengan cara crosslink menggunakan katalis H2SO4 pekat terhadap 25,26,27,28-tetraalliloksikaliks[4]arena, tetra-p-allilkaliks[4]arena, tetrap- allilkaliks[4]arena tetra ester asetat dan tetra-p-allilkaliks[4]arena tetra asam asetat. Sintesis kaliks[4]arena menggunakan p-t-butilfenol sebagai material awal. Identifikasi struktur resin menggunakan spektrofotometri FTIR dan 1H-NMR. Karakterisasi resin meliputi morfologi permukaan, analisis luas permukaan, ukuran serta distribusi pori menggunakan SEM dan SAA. Pemanfaatan resin sebagai adsorben kation logam berat Cr(III), Pb(II), Ag(I), dan Cd(II) dilakukan dengan menggunakan sistem batch. Kajian yang dilakukan meliputi pengaruh tingkat keasaman (pH), pengaruh variasi waktu kontak dan pengaruh variasi konsentrasi awal larutan logam. Pada pemanfaatan resin poli-kaliks[4]arena sebagai antidotum dipelajari pengaruh adsorpsi resin terhadap mineral esensial Ca, Fe dan Zn, penentuan koefisien partisi lemak/air resin, uji toksisitas akut, dan uji aktivitas antidotum keracunan kadmium. Secara umum, interaksi adsorpsi resin poli-kaliks[4]arena mempunyai pH optimum sekitar pH 4 hingga pH 6, mencapai keadaan setimbang pada waktu interaksi 40 menit, dan cenderung mengikuti persamaan kinetika orde dua Ho, dengan nilai R2 pada berbagai interaksi adsorben-adsorbat menunjukkan nilai yang bervariasi pada kisaran 0,9103 hingga 0,9998. Isoterm adsorpsi resin polikaliks[ 4]arena cenderung mengikuti pola isoterm adsorpsi Langmuir. Kapasitas adsorpsi tertinggi pada interaksi adsorpsi resin poli-tetra-p-allilkaliks[4]arena– Cr(III) sebesar 345,0 μmol/g (17,92 mg/g) dan terendah pada interaksi resin politetra- p-allilkaliks[4]arena–Pb(II) sebesar 32,3 μmol/g (6,69 mg/g). Berdasarkan hasil uji in vitro adsorpsi resin poli-25,26,27,28- tetraalliloksikaliks[4]arena terhadap logam esensial, dapat disimpulkan bahwa penggunaan resin sebagai antidotum kadmium harus disertai pemberian suplemen yang mengandung Fe dan Zn. Koefisien partisi resin pada pH 3,5 sebesar 0,80±0,05, sedangkan pada pH 7,4 sebesar -0,22±0,05. Uji toksisitas akut resin sebagai dosis oral tunggal pada mencit putih galur BALB/c, jantan maupun betina mempunyai LD50 lebih besar dari 260 mg/Kg BB. Hasil uji aktifitas antidotum, pada konsentrasi yang sama dengan dimerkaprol (0,65 mg/Kg BB) sebagai antidotum standar, resin poli-25,26,27,28-tetraalliloksikaliks[4]arena mempunyai kemampuan yang lebih baik dalam menurunkan kandungan kadmium pada ginjal, hati maupun darah secara berturutan yaitu sebesar 73,95 %; 84,27 % dan 87,83 %; sedangkan pada dimerkaprol sebesar 66,21 %; 70,71 % dan 49,74 %.

Synthesis of poly-calix[4]arene resins and their applications as adsorbent as well as antidote for heavy metal poisoning had been conducted. The synthesis of poly-calix[4]arenes from 25,26,27,28-tetraallyloxycalix[4]arene, tetra-pallylcalix[ 4]arene, tetra-p-allylcalix[4]arene tetra acetic ester and tetra-pallylcalix[ 4]arene tetra acetic acid were performed via crosslink reaction in the presence of concentrated sulfuric acid. Calix[4]arenes were synthesized using p-tbutylphenol as a starting material. Structure identifications were carried out by means of FTIR and 1H-NMR spectrometers. Further characterizations of the resins included surface morphology, surface area analysis, size and pores distribution using SEM and SAA. The synthesized resins were applied as adsorbent for Cr(III), Pb(II), Ag(I) and Cd(II) heavy metal cations. The adsorption study was conducted in batch system by investigating the effects of acidity (pH), contact time and initial concentration of heavy metal. In their application as antidote, adsorption of essential minerals of Ca, Fe and Zn, determination of partition coefficient, tests of acute toxicity as well as antidote activity on Cd poisoning were also studied. In general, the adsorption of heavy metal on the resins had the optimum pH in region of 4–6 and reached the equilibrium condition in 40 minutes. The adsorption processes followed second order adsorption kinetic model of Ho, where the R2 for every interaction of adsorbent-adsorbate varied from 0.9103 to 0.9998. The adsorption of cations on the resins tended to follow the Langmuir isothermal pattern. The highest adsorption capacity was obtained from the interaction between poly-tetra-p-allylcalix[4]arene and Cr(III), 345.0 μmol/g (17.92 mg/g), whereas the lowest capacity belonged to that of poly-tetra-pallylcalix[ 4]arene and Pb(II), 32.3 μmol/g (6.69 mg/g). Based on the in vitro study of the essential metal adsorption, it could be concluded that the utilization of poly-25,26,27,28-tetraallyloxycalix[4]arene resin as antidote in Cd poisoning had to be coupled with the provision of supplement containing Fe and Zn. Partition coefficient of poly-25,26,27,28- tetraallyloxycalix[4]arene at pH 3.5 and 7.4 were 0.80±0.05 and –0.22±0.05, respectively. Acute toxicity test of poly-25,26,27,28-tetraallyloxycalix[4]arene as single oral dose on white mice (strain of BALB/c), male and female showed that the LD50 was higher than 260 mg/kg BW. The antidote activity test at the same concentration with dimercaprol (0.65 mg/kg BW) as standard antidote showed that the resin displayed better activity in decreasing Cd concentration in kidney, liver and blood which were 73.95%, 84.27%, and 87.83%, respectively and 66.21%, 70.71%, and 49.74%, respectively for dimercaprol.

Kata Kunci : resin poli-kaliks[4]arena, crosslink, adsorpsi, logam berat, antidotum