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Jaya Hardi
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INDONESIA
KOVALEN: Jurnal Riset Kimia
Published by Universitas Tadulako
ISSN : -     EISSN : 24775398     DOI : https://doi.org/10.22487/kovalen
Core Subject : Science, Engineering,
Chemical Engineering, Chemistry & Bioengineering Chemistry
KOVALEN: Jurnal Riset Kimia is a peer-reviewed journal of chemistry published by the Tadulako University, Indonesia. This journal concern with publishing the original research articles, review articles, and the current issues related to chemistry. Publishing frequency 3 issues per year, in April, August, and December.
Arjuna Subject : Kimia(semua kategori) - Kimia (Lain-Lain)
Articles 325 Documents
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BIOSORBEN KITOSAN CANGKANG KEONG SAWAH TERHADAP PENYERAPAN ZAT WARNA METHYLENE BLUE iget rais; Nurhaeni; Ruslan; Dwi Juli Pusptasari
KOVALEN: Jurnal Riset Kimia Vol. 5 No. 2 (2019): Edisi Agustus
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (352.579 KB) | DOI: 10.22487/kovalen.2019.v5.i2.12826

Abstract

Biosorbent studies on methylene blue absorption using chitosan from rice conch shell have been carried out. This research was carried out with variations in contact time of 1, 2, 3, 4, 5, and 6 hours with the aim to determine the contact time required to adsorb Methylene Blue dyes by chitosan from rice conch shell with the highest adsorption capacity. The results showed that the contact time required to adsorb Methylene Blue dye by a chitosan from rice conch shell was 6 hours with the highest adsorption capacity of 85.05%. Keywords: Chitosan, adsorption, Methylene Blue
FORMULASI PAKAN UNGGUL BERBASIS BIOTEKNOLOGI LIMBAH ORGANIK LOKAL UNTUK IKAN LELE ORGANIK KUALITAS EKSPOR Yusafir Hala; syahruddin udin kasim; Indah Raya
KOVALEN: Jurnal Riset Kimia Vol. 5 No. 2 (2019): Edisi Agustus
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (375.741 KB) | DOI: 10.22487/kovalen.2019.v5.i2.12926

Abstract

Research on Superior Feed Formulations Based on Local Organic waste Biotechnology for Export quality organic Catfish. Research Objective: The discovery of feed types of tilapia and organic catfish that have export quality nutritional content based on the best quality local marine organic waste through a touch of biotechnology. Furthermore, the complete chemical composition of the waste used and feed components is obtained. Research Methods: Determine the best composition of biomass of marine organic waste and local onshore organic wastes with the highest levels of protein and carbohydrates and integrated with other wastes. The nutritional content is analyzed, namely: Carbohydrates, fats, proteins, and supporting minerals, namely: Fe, K and Ca. Instrumentation used to support the research objectives is AAS and HPLC. Research Results: Export quality organic catfish pellet feed in the form of waste: marine fish, sea shrimp waste, sea crab waste, rice bran waste, corn waste, mixed organic waste, golden snail waste, seaweed waste and coconut water waste respectively (27; 15; 7.5; 33; 3; 2.5; 5; 2.5 and 2) %b/ b, starch 2% b/b and marine phytoplankton biomass 0.5% b/b. The nutritional content of organic catfish pellets that have been produced, namely: 51% protein b/b, 24% carbohydrate b/b, 9% fat b/b, crude fiber 8%b/b, water content 2 - 2.5%b/b, mineral Fe 1% b/b, mineral K 1% b/b, mineral Ca 1%b/b, ash content 2 - 2.5%b/b. Feed packing for export quality organic catfish pellets is given the "SANTARI-KU" label. Keywords: Superior feed, local organic waste biotechnology, export quality organic catfish, Santari-ku.
ADSORPSI LOGAM Pb dan Cu DARI PELUMAS BEKAS MENGGUNAKAN BLENDING SELULOSA ASETAT-KITOSAN Fitra Langgeng Mangesti; Husain Sosidi; Prismawiryanti; Syamsuddin
KOVALEN: Jurnal Riset Kimia Vol. 5 No. 2 (2019): Edisi Agustus
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (490.642 KB) | DOI: 10.22487/kovalen.2019.v5.i2.12990

Abstract

Research on adsorption of Pb and Cu metals from used lubricants has been carried out using cellulose acetate-chitosan blending which aims to determine the best ratio and pH between cellulose acetate and chitosan which can adsorb metal Pb and Cu from used lubricants. Cellulose acetate was synthesized through the acetylation method using cellulose extracted from palm fiber coir. The obtained cellulose acetate is brown fine powder with a yield of 62% and has a water content of 20%. Cellulose acetate was characterized using FT-IR while adsorption of Pb and Cu metals from used lubricants using AAS. The results of FT-IR analysis showed the formation of cellulose acetate with an absorption band of 1637.56 cm-1 which proved the presence of carbonyl groups (C = O). The AAS results showed that the best ratio and pH to absorb Pb and Cu metals in used lubricants is 3:1 with pH 6. Keywords: palm oil coir, acetate cellulose, chitosan, used lubricants
PENGARUH RASIO PELARUT TERHADAP EKSTRAKSI DARI KULIT BUAH NAGA MERAH (Hylocereus polyrhizus) Amalia Noviyanty; Chitra Anggriani Salingkat; Syamsiar Syamsiar
KOVALEN: Jurnal Riset Kimia Vol. 5 No. 3 (2019): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (642.486 KB) | DOI: 10.22487/kovalen.2019.v5.i3.14029

Abstract

This study aims to determine the effect of the ratio of solvents to extract yield, phenolics total and IC50 values ​​of red dragon fruit peel and also get the optimal solvent ratio to obtain extract yield, phenolics total and the highest or best IC50 values ​​of red dragon fruit peel extracts. The solvent ratio used there are 6 levels of the ratio: 2:1; 3:1; 4:1; 5:1; 6:1 and 7:1 (v/w). The data obtained were analyzed using a Completely Randomized Design that was applied to observations of extract yield, phenolics total and IC50 values, if the treatment had a very significant or significant effect followed by continued Tukey HSD test at 1% or 5% level. The results showed that the solvent ratio very significantly affected the extract yield, phenolics total and IC50 value of red dragon fruit peel extract. The solvent ratio of 4:1 (v/w) produced extract yield, phenolics total and IC50 values the highest or best i.e 26.22%, 71.56 ppm, and 124.62 ppm. Keywords : IC50, the red dragon fruit skin, solvent ratio, phenolics total
PENGARUH JENIS PELARUT TERHADAP EKSTRAKSI DARI KULIT BUAH NAGA MERAH (Hylocereus polyrhizus) Amalia Noviyanty; Chitra Anggriani Salingkat; Syamsiar Syamsiar
KOVALEN: Jurnal Riset Kimia Vol. 5 No. 3 (2019): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (667.879 KB) | DOI: 10.22487/kovalen.2019.v5.i3.14037

Abstract

This study aims to determine the effect of the type of solvent on extract yield, total phenolics and IC50 values of the skin of red dragon fruit and also obtain the best type of solvent that provides extract rendement, total phenolics and the highest or best IC50 value for extracting red dragon fruit peels. There are 3 types of solvents used (95% ethanol, ethyl acetate and acetone: water (7: 3) with a sample-solvent ratio (5:1 v/b). The data obtained were analyzed using a Completely Randomized Design that was applied to observations of extract rendemen, phenolics total and IC50 values, if the treatment had a very significant or significant effect followed by continued BNJ test at 1% or 5% level. The results showed that the solvent ratio very significantly affected the extract rendemen, phenolics total and IC50 value of red dragon fruit peel extract. Ethanol 95% solvent is the best solvent for extracting dragon fruit peels because it has the highest yield (26.15%), total phenolic (64.75 ppm) and antioxidant activity (IC50 value) (120.53 ppm) highest or best. Keywords : IC50, the red dragon fruit skin, solvent ratio, extract yield, phenolics total
KARAKTERISASI SILIKA DARI ABU AMPAS TEBU Tifa Paramitha; Tri Reksa Saputra; Amelia Nur Aliah; Arijan Vevayose Tarigan; Mukhtar Ghozali
KOVALEN: Jurnal Riset Kimia Vol. 5 No. 3 (2019): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (443.321 KB) | DOI: 10.22487/kovalen.2019.v5.i3.14309

Abstract

Silica has been successfully extracted from sugarcane bagasse ash by using alkali method. Extraction was carried out using sodium hydroxide solution to obtain sodium silicate solution and solid residue. Then, hydrochloric acid solution was added to sodium silicate solution until pH of solution was 7 and silica was formed. Furthermore, silica was heated in oven at 150 ˚C and calcined at 700 ˚C. Variation of this study were extraction time (1, 2 and 3 hours). The synthesized silica were characterized functional groups, acidity level, water adsorption ability and adsorption ability of Cu2+ ion. The results of FTIR analysis showed that all silica contain siloxane group. Silanol group did not appear because during calcination process occured the condensation reaction of silanol group. Other characterization results showed that silica with extraction time of 2 hours had highest acidity level, water adsorption ability and adsorption ability of Cu2+ ion, which were 6.201 mmol/gram, 86.41% and 92.55%. Keywords : bagasse ash, extraction, silica, siloxane
PRODUKSI METIL OLEAT MELALUI REAKSI METANOLISIS MINYAK BIJI KELOR (Moringa oleifera Lam) Fatiah Riskah; Ahmad Ridhay; Mappiratu Mappiratu; Erwin Abdul Rahim
KOVALEN: Jurnal Riset Kimia Vol. 5 No. 1 (2019): Edisi April
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (656.369 KB) | DOI: 10.22487/kovalen.2019.v5.i1.14561

Abstract

Telah dilakukan penelitian yang bertujuan untuk mendapatkan fraksi massa metil ester asam oleat tertinggi dari rasio minyak biji kelor/metanol (v/v) serta waktu reaksi dalam proses metanolisis minyak biji kelor serta komposisi dari metil ester asam oleat. Penelitian ini dilakukan dengan menggunakan Rancangan Acak Lengkap (RAL) dengan variasi rasio minyak biji kelor/metanol 1:3, 1:4, 1:5, 1:6 dan 1:7 (v/v) serta variasi waktu reaksi 30 menit, 60 menit, 90 menit, 120 menit dan 150 menit. Hasil yang diperoleh menunjukkan bahwa peningkatan rasio minyak biji kelor/metanol  meningkatkan fraksi massa metil ester asam oleat dengan fraksi massa maksimum (72.61%) terdapat pada penggunaan rasio minyak biji kelor/metanol 1:7 (v/v). Demikian pula pada pengaruh waktu reaksi yang menunjukkan bahwa peningkatan waktu reaksi meningkatkan fraksi massa metil ester asam oleat dengan fraksi massa maksimum (78.75%) terdapat pada penggunaan waktu reaksi 150 menit. Berdasarkan hasil analisis GC-MS diperoleh senyawa dominan penyusun metil ester tersebut adalah metil oleat persentase sebesar 48.25%, kemudian metil stearat dengan persentase sebesar 7.67%, selanjutnya metil palmitat dengan persentase sebesar 5.14 dan senyawa yang belum diketahui secara pasti dengan persentase sebesar 38.94%Kata Kunci: Minyak biji kelor, metil oleat,metanolisis
UJI STABILITAS PIGMEN EKSTRAK UBI BANGGAI (Dioscorea bulbifera var celebica Burkill) PADA BERBAGAI VARIASI pH DAN LAMA PAPARAN SINAR MATAHARI Bryan Agung Rundubelo; Ahmad Ridhay; Jaya Hardi; Dwi Juli Pusptasari
KOVALEN: Jurnal Riset Kimia Vol. 5 No. 1 (2019): Edisi April
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (748.495 KB) | DOI: 10.22487/kovalen.2019.v5.i1.14562

Abstract

Penelitian tentang potensi ubi banggai (Dioscorea bulbifera var celebica Burkill)  sebagai pewarna alami makanan dan minuman yang ditinjau dari stabilitas pH dan paparan sinar matahari telah dilaksanakan. Tujuan dari penelitian ini adalah mengetahui kestabilan ekstrak ubi banggai terhadap pengaruh pH dan terhadap paparan sinar matahari selama masa penyimpanan. Waktu yang digunakan adalah 10 hari untuk penyimpanan terhadap pengaruh pH dan 5 jam untuk paparan sinar matahari. Hasil penelitian menunjukan zat warna ekstrak ubi banggai stabil pada pH 2 setelah masa penyimpanan 10 hari dengan presentasi degradasi 37.38 % sementara pengaruh paparan sinar matahari menghasilkan degradasi terendah pada botol gelap yaitu 36,91 % dibandingkan dengan botol bening 41,96 %.Kata Kunci : Zat warna, stabilitas ubi banggai, degradasi
MIKROENKAPSULASI EKSTRAK AMPAS JAHE MERAH DARI HASIL PEMISAHAN MINYAK JAHE MERAH Novaldi Novaldi; Prismawiryanti Prismawiryanti; Jaya Hardi; Hardi Ys
KOVALEN: Jurnal Riset Kimia Vol. 5 No. 1 (2019): Edisi April
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (671.756 KB) | DOI: 10.22487/kovalen.2019.v5.i1.14563

Abstract

Ekstrak ampas jahe merah hasil penyulingan minyak jahe merah mengandung senyawa oleoresin yang mudah rusak. Untuk menahan kerusakannya dilakukan mikroenkapsulasi menggunakan maltodekstrin. Ekstraksi dilakukan menggunakan pelarut etanol 96% dengan lima rasio perbandingan, yaitu 1:6, 1:7, 1:8, 1:9 dan 1:10 (b/v). Mikroenkapsulasi dilakukan metode penyalutan dan teknik freeze drying. Perbandingan maltodekstrin dan ekstrak ampas jahe merah yaitu 1:6, 1:7, 1:8, 1:9 dan 1:10 (b/b). Hasil penelitian menunjukkan bahwa rendemen ekstrak ampas jahe merah yang diperoleh tertinggi pada rasio 1:10 dengan kadar 31,82%. Efisiensi penyalutan ekstrak ampas jahe merah dengan maltodekstrin yang diperoleh tertinggi pada rasio 1:6 yaitu 55,04%.Kata kunci: Ekstrak ampas jahe merah, freeze drying, penyalutan, maltodekstrin
KAJIAN AKTIVITAS ANTIOKSIDAN MIKROKAPSUL EKSTRAK KULIT TERONG UNGU (Solanum melongena L) Efin Lestari; Ni Ketut Sumarni; Mappiratu Mappiratu
KOVALEN: Jurnal Riset Kimia Vol. 5 No. 3 (2019): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (752.078 KB) | DOI: 10.22487/kovalen.2019.v5.i3.14628

Abstract

Study about antioxidant activity of microcapsule of purple eggplant (Solanum melongena L) peel extract has ben done. The research aimed to find the best pH and coating ratio for yielding microcapsule with the highest antioxidant activity. It was done by applying 5 levels of both pH variation of 2, 3, 4, 5, 6 and maltodextrin ratio of 1:1, 2:1, 3:1, 4:1, 5:1 (w/v). The determination of antioxidant activity was done by DPPH method. The result showed that at pH 2 and 1:1 of maltodextrin coating ratio were the best condition to yield the highest antioxidant activity i.e 32.54 % and 96.31 %, respectively. Keywords: Purple eggplant peel, maltodextrin, microcapsule, antioxidant activity

Page 13 of 33 | Total Record : 325

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