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Perbandingan Metode Potensiometri dan Spektrofotometri pada Penentuan Formalin Dewi Umaningrum; Radna Nurmasari; Maria Dewi Astuti; Ani Mulyasuryani; Diah Mardiana
Jurnal Fisika FLUX Vol 1, No 1 (2019): Jurnal Fisika Flux Edisi Khusus Januari 2019
Publisher : Lambung Mangkurat University Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/flux.v1i1.6148

Abstract

Penelitian tentang penentuan formalin menggunakan metode potensiometri dan spektrofotometri telah dilakukan. Tujuan dari penelitian ini adalah untuk membandingkan hasil pengukuran kadar formalin antara metode potensiometri menggunakan sensor berbasis Screen Printed Carbon Electrode (SPCE) dengan metode standar spektrofotometri. Metode penelitian diawali dengan membuat sensor formalin yang digunakan untuk mengukur kadar formalin menggunakan selulosa asetat sebagai ionofor. Tahap berikutnya adalah mengukur kadar formalin sampel menggunakan sensor dan metode standar spektrofotometri. Hasil pengukuran kadar formalin kemudian dibandingkan diantara kedua metode tersebut. Hasil penelitian menunjukkan bahwa pada penentuan formalin antara kedua metode tersebut tidak menunjukkan beda nyata.
CPO Bleaching Optimization Using Activated Charcoal And Bentonite A Abdullah; Yudhistira Abdi Atmanegara; Radna Nurmasari
Jurnal ILMU DASAR Vol 11 No 2 (2010)
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (146.652 KB)

Abstract

Research of Crude Palm Oil (CPO) bleaching optimization using activated charcoal and bentonite on biodiesel synthesize had been done. The aim of this research is to find optimum condition of bleaching process, by making variation of activated charcoal and bentonite ratio as adsorbent (1:0, 1:10, 1:15, 1:20 and 0:1), temperature (non heated, 40-50oC, 60-70oC, 80-90oC and 100-110oC) and time (1; 1,5; 2; 2,5 and 3 hours). The results of this research will be used as optimal conditions for synthesizing biodiesel. Optimum condition was determined by observing the lowest absorbent which was measured by using spectronic-20 on 445 nm. Results showed that optimum activated charcoal and bentonite adsorbent ratio was 0:1, optimum temperature was 100- 110oC and optimum time was 3 hours.
IMMOBILIZATION OF HUMIC ACID ONTO CHITOSAN USING TOSYLATION METHOD WITH 1,4-BUTANEDIOL AS A SPACER ARM Uripto Trisno Santoso; Radna Nurmasari; Dewi Umaningrum; Sri Juari Santosa; Bambang Rusdiarso; Dwi Siswanta
Indonesian Journal of Chemistry Vol 12, No 1 (2012)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (420.224 KB) | DOI: 10.22146/ijc.21369

Abstract

Immobilization of humic acid (HA) onto chitosan using tosylation method with 1,4-butanediol as a spacer arm has been evaluated. Chitosan was phthaloylated selectively using phthalic anhydride in dimethylformamide as solvent with addition of 5% water (v/v) as cosolvent prior to be tosylated. N-phthaloyl-chitosan and HA were tosylated using tosyl chloride in excess and triethylamine as catalyst at temperature < 10 °C for 12 h. The 6-O-tosyl-N-phthaloyl-chitosan was reacted with 1,4-butanediol in order to obtain a spacer arm attached chitosan. The 6-O-butanol-N-phthaloyl-chitosan was activated by reacting with tosyl chloride. For evaluation on immobilization of HA on chitosan with and without spacer arm, 6-O-tosylbutane-N-phthaloyl-chitosan was reacted with HA and the 6-O-tosyl-N-phthaloyl-chitosan was reacted with HA. The HA immobilized onto chitosan was characterized by XRD and FTIR spectrophotometric method. The result showed that HA can be immobilized covalently onto chitosan after attaching 1,4-butanediol as spacer arm onto 6-O-tosyl-N-phthaloyl-chitosan and activating the product with tosyl chloride, but HA cannot be reacted directly onto 6-O-tosyl-N-phthaloyl-chitosan.
ADSORPTION KINETICS OF Pb(II), Cd(II) AND Cr(III) ON ADSORBENT PRODUCED BY PROTECTED-CROSSLINKING OF HUMIC ACID-CHITOSAN Dewi Umaningrum; Uripto Trisno Santoso; Radna Nurmasari; Rahmat Yunus
Indonesian Journal of Chemistry Vol 10, No 1 (2010)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (295.532 KB) | DOI: 10.22146/ijc.21484

Abstract

Study on adsorption kinetics of of Pb(II), Cd(II) and Cr(III) on adsorbent which was produced by protected-crosslinking of humic acid-chitosan has been done. The Langmuir-Hinshelwood, pseudo first- and second-order kinetics models were used to describe the kinetic data, and the rate constants of adsorption were also evaluated. The experimental data fitted well the second-order kinetics model, indicating that the chemical sorption is the rate-limiting step, instead of mass transfer. The initial metal ion concentration significantly affects the adsorption rate. An increase in initial metal ion concentration results in the decrease in adsorption rate of the metals.
IMMOBILIZATION OF HUMIC ACID ON CHITOSAN BEADS BY PROTECTED CROSS-LINKING METHOD AND ITS APPLICATION AS SORBENT FOR Pb(II) Radna Nurmasari; Uripto Trisno Santoso; Dewi Umaningrum; Taufiqur Rohman
Indonesian Journal of Chemistry Vol 10, No 1 (2010)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (337.212 KB) | DOI: 10.22146/ijc.21485

Abstract

Immobilization of humic acid (HA) on chitosan beads has been done using a protected cross-linking reaction method and the product was then utilized as sorbent for Pb(II). Protection of the active sites of HA was carried out by interacting HA with Pb(II) before performing the cross-linking reaction in order to maintain its adsorption capacity. Protected-HA was cross-linked with chitosan beads using glutaraldehyde in order to obtain sorbent insoluble both in aqueous acidic and basic solution. The result showed that the amount of immobilized HA on beads chitosan was 88.60% by weight. The adsorption capacity of the protected-sorbent beads for Pb(II) was 784 mg/g. As a comparison, the adsorption capacity of the non-protected sorbent beads for Pb(II) was only 142 mg/g.
IMMOBILIZATION OF HUMIC ACID ON CHITOSAN USING PROTECTED CROSS-LINKING REACTION METHOD AND ITS APPLICATION AS SORBENT FOR Pb(II), Cd(II), AND Cr(III) Uripto Trisno Santoso; Dewi Umaningrum; Utami Irawati; Radna Nurmasari
Indonesian Journal of Chemistry Vol 8, No 2 (2008)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (253.04 KB) | DOI: 10.22146/ijc.21620

Abstract

Immobilization of humic acid (HA) on chitosan has been done by using a protected cross-linking reaction method and the product was then utilized as sorbent for Pb(II), Cd(II), and Cr(III). HA was cross-linked with chitosan by using glutaraldehyde in order to obtain sorbent insoluble in aqueous acidic and basic solution. Protection of the active sites of HA was carried out by interacting HA with Pb(II) before performing the cross-lingking reaction in order to maintain its adsorption capacity The result showed that the amount of immobilized HA on chitosan was 99.7% by weight. The solubility of the immobilized HA were < 0.5% at pH 6 and < 1.0% at pH 12. The amount of immobilized HA and its solubility indicated that the protection pretreatment did not interfere the cross-linking reaction between HA and chitosan. The adsorption capacity of the sorbent for Pb(II), Cd(II), and Cr(III) were 416.7 mg/g, 332.3 mg/g, dan 714.3 mg/g, respectively.
ELARUTAN FOSFAT YANG TERJERAP PADA TANAH MINERAL MASAM OLEH ASAM FULVAT DARI TANAH GAMBUT Uripto Trisno Santoso; Dewi Umaningrum; Radna Nurmasari; Amelia Harianti
Jurnal Sains dan Terapan Kimia Vol 9, No 1 (2015)
Publisher : Program Studi Kimia, Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (328.069 KB) | DOI: 10.20527/jstk.v9i1.2145

Abstract

Telah dilakukan kajian efektivitas asam fulvat dalam melarutkan fosfat yang terjerap pada tanah mineral masam pada skala laboratorium. Dua parameter yang mempengaruhi pelarutan fosfat, yakni konsentrasi awal asam fulvat dan waktu reaksi, telah dipelajari secara statistik. Hasil penelitian menunjukkan bahwa waktu reaksi mempengaruhi jumlah P-tersedia secara signifikan. Keberadaan asam fulvat dapat melarutkan fosfat yang terjerap secara signifikan. Namun demikian, variasi konsentrasi asam fulvat 50 hingga 250 ppm tidak meningkatkan kemampuan asam fulvat dalam melarutkan fosfat yang terjerap tetapi pada konsentrasi asam fulvat 500 ppm terjadi peningkatan P-tersedia secara signifikan. Kata kunci: asam fulvat, pelarutan, fosfat, tanah mineral masam 
ISOLASI SELULOSA DARI JERAMI PADI MENGGUNAKAN VARIASI KONSENTRASI BASA Dewi Umaningrum; Radna Nurmasari; Maria Dewi Astuti; Mardhatillah Mardhatillah; Ani Mulyasuryani; Diah Mardiana
Jurnal Sains dan Terapan Kimia Vol 12, No 1 (2018)
Publisher : Program Studi Kimia, Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (637.665 KB) | DOI: 10.20527/jstk.v12i1.4652

Abstract

Telah dilakukan penelitian tentang isolasi selulosa dari jerami padi menggunakan variasi konsentrasi basa. Pada penelitian ini dipelajari tentang pengaruh basa dan variasi konsentrasinya dalam isolasi selulosa dari jerami padi. Kajian pengaruh basa dan konsentrasi dilakukan dengan melarutkan ekstrak jerami padi pada NaOH dan KOH dengan variasi konsentrasi 1%, 3%, 5%, 7% dan 9% dan kemudian dilakukan analisis IR terhadap selulosa hasil isolasi serta dihitung rendemen selulosa dan lignin sisa. Hasil penelitian menunjukkan bahwa pada isolasi selulosa dari jerami padi digunakan NaOH 7% dengan rendemen selulosa yang diperoleh sebesar 33,63% dengan lignin sisa sebesar 2,42%.Kata kunci : isolasi, selulosa, lignin sisa
SINTESIS DAN KARAKTERISASI ADSORBEN ASAM HUMAT TERIMOBILISASI PADA HIBRIDA MERKAPTO SILIKA DARI ABU SEKAM PADI Radna Nurmasari; Dwi Rasy Mujiyanti; Hari Fitra
Jurnal Sains dan Terapan Kimia Vol 7, No 2 (2013)
Publisher : Program Studi Kimia, Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (226.777 KB) | DOI: 10.20527/jstk.v7i2.2127

Abstract

Telah dilakukan sintesis dan karakterisasi asam humat (AH) pada hibrida merkapto silika (HMS) dengan metode imobilisasi menjadi asam humat–hibrida merkapto silika (AH-HMS). Penelitian ini bertujuan mensintesis asam humat pada hibrida merkapto silika dan menentukan karakteristik gugus fungsional yang berperan aktif pada asam humat, HMS dan adsorben asam humat yang terimobilisasi pada hibrida merkapto silika dari abu sekam padi. Hasil penelitian menunjukkan bahwa karakteristik gugus fungsi yang berperan dalam adsorpsi logam Pb(II) dari AH-HMS yaitu gugus –SH, pada AH yaitu gugus –COOH, dan pada HMS yaitu gugus –SH. Kata kunci: AH-HMS, pH, kapasitas adsorpsi, gugus fungsi. 
KOMPOSISI MEMBRAN OPTIMUM PADA ELEKTRODE SELEKTIF ION METHANIL YELLOW Dewi Umaningrum; Dahlena Ariyani; Radna Nurmasari
Jurnal Sains dan Terapan Kimia Vol 9, No 2 (2015)
Publisher : Program Studi Kimia, Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (399.061 KB) | DOI: 10.20527/jstk.v9i2.2150

Abstract

Telah dilakukan penelitian tentang komposisi membran optimum pada elektrode selektif ion Methanil Yellow. Penelitian ini bertujuan untuk mengetahui komposisi membran optimum campuran antara kitosan, polivinil klorida (PVC) dan dioktilftalat (DOP) pada elektrode selektif ion Methanil Yellow. Tahapan awal yang dilakukan adalah pembuatan badan elektrode dan kemudian dilanjutkan dengan melakukan variasi komposisi terhadap membran campuran kitosan, polivinil klorida (PVC) dan dioktilftalat (DOP). Hasil penelitian menunjukkan bahwa komposisi membran optimum kitosan:PVC:DOP sebesar 20:30:50 dengan harga Nernst sebesar 56,82 mV/dekade konsentrasi. Kata kunci: Komposisi membran, elektode selektif ion, methanil yellow, kitosan, polivinil klorida (PVC), dioktilftalat (DOP)