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ALCHEMY Jurnal Penelitian Kimia
ISSN : 14124092     EISSN : 24434183     DOI : -
ALCHEMY Jurnal Penelitian Kimia is a chemistry journal published by Sebelas Maret University, Surakarta. ALCHEMY Jurnal Penelitian Kimia publishes original research articles or review articles in organic chemistry, inorganic chemistry, analytical chemistry, physical chemistry, biochemistry, and environmental chemistry.
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Articles 285 Documents
Formulasi dan Uji Aktivitas Krim Pengkelat Merkuri Berbahan Dasar Ekstrak Etanol Alga Coklat (Sargassum sp.) Inda Putrinesia; Yoga Pratama; Nurul Asyikin; Winda Rahmalia
ALCHEMY Jurnal Penelitian Kimia Vol 14, No 1 (2018): March
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.14.1.12242.152-163

Abstract

Telah dilakukan penelitian tentang formulasi dan uji aktivitas krim pengkelat merkuri berbahan dasar ekstrak etanol alga coklat (Sargassum sp.) telah dilakukan. Krim diformulasikan dengan beberapa bahan seperti vaselin, gliserol, asam askorbat, karbomer, setil alkohol, dan NaOH. Parameter yang dievaluasi diantaranya organoleptik krim, homogenitas, pH, daya sebar, tipe krim, iritasi kulit, dan daya tercuci krim. Aktivitas pengkelatan diamati dengan menganalisis kandungan merkuri pada kulit tikus yang sebelumnya diberikan krim bermerkuri dibandingkan dengan kulit tikus yang telah dioleskan krim pengkelat merkuri berbahan dasar ekstrak etanol alga coklat. Spektrum Fourier Transform Infrared Spectroscopy (FT-IR) menunjukkan bahwa ekstrak etanol alga coklat diindikasikan mengandung glutation. Berdasarkan parameter evaluasi krim, formulasi terbaik adalah krim dengan komposisi ekstrak alga coklat sebanyak 0,035% w/v terhadap volume krim, yang ditandai dengan krim yang berbentuk gel kental dan tidak berbau serta memiliki tekstur seperti krim wajah pada umumnya, yaitu lembut dan sedikit berminyak. Krim bersifat homogen dan stabil hingga hari ke 21 percobaan dengan pH=5. Krim juga tidak menimbulkan iritasi dan dapat tercuci habis tanpa bekas. Hasil analisis AAS membuktikan bahwa penggunaan krim pengkelat merkuri berbahan dasar esktrak etanol alga coklat selama kurang dari 2 minggu dengan dosis pemberian 1 kali sehari mampu menyerap merkuri pada tikus dengan aktivitas penyerapan sebesar 50%.Formulation and Activity Test of Mercury Chelator Cream of Ethanol Extract of Brown Algae (Sargassum Sp.). Research on the study of formulation an activity test of mercury chelator cream from ethanol extract has successfully done. The cream was formulated with ingredients such as vaseline, glycerol, ascorbic acid, carbomer, cetyl alcohol, and sodium hydroxide. Parameters were evaluated against organoleptic, homogenity, pH, dispersion type of cream, skin irritation test and washing test. The mercury chelating activity was observed by analyzing mercury concentration in mercury induced mouse skin. The FTIR spectrum shows that ethanol extract of brown algae was dominated by glutathione functional group. The best cream formulation was composed by 0,035% (w/v) brown algae, formed as a creamy gel that was thick and odorless and had a texture like soft facial cream in general with slightly oily.The cream was homogeneous and stable until the 21st day of the experiment with pH = 5. The cream produced no skin irritation and could be washed out without a trace. The results of AAS analysis proved that the use of brown algae ethanol extract-based mercury chelating cream for less than 2 weeks with a dose of 1 time a day could absorb mercury in mouse skin with absorption activity of 50%.
Reverse Microemulsion of Igepal CO-720 System as Microreactor For CdS Synthesis Fitria Rahmawati; Indah Rizki Fitriani; Abu Masykur
ALCHEMY Jurnal Penelitian Kimia Vol 10, No 2 (2014): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.10.2.538.157-172

Abstract

A Research on CdS synthesis in reverse microemulsion of Igepal CO-720 system has been conducted at various weight ratio of water to surfactant. Igepal CO-720 naturally forms  oil  in  water  (o/w)  emulsion  type  due  to  its  high  HLB  (Hydrophilic -Lipophilic Balance)  value.  Therefore,  in  this  research  the  Igepal  CO-720  system  was  inversed  into water  in  oil  (w/o)  system  before  it  was  used  as  microreactor  for  CdS  synthesis.  As comparison,  a  system  of  AOT  (Aerosol  OT;  sodium  bis (2-ethylhexyl)  sulfosuccinate) which  is  naturally  w/o  system  was  also  used  as  microreactor  for  CdS  synthesis.  The prepared  CdS  was  analyzed  by  X-ray  diffraction  for  crystal  identification,  scanning electron microscope for morphological analysis, UV-Vis for absorption edge determination and  photoelectrochemical  testing  for  photoactivity.  The  results  show that the  Igepal  CO -720  system can  be  inverted  into  w/o  system  and  can  be  used  as  microreactor  for  CdS synthesis. The prepared CdS is in nanosize with the average diameter of 2.517  ±  0.014 nm and  the  average  gap  energy  of  3.805  ±  0.178  eV.  The  prepared  CdS  in  Igepal  CO-720 system has less regular form in comparison with morphology of the prepared CdS in AOT system. As the ω  values decreases the particle diameter decreases, the gap energy increases and the %  IPCE increases. It indicates that high surfactant concentration allows small size micelles  formation  and  produced  smaller  CdS  particle  that  has  high  surface  area  and therefore  provide  higher  photocatalytic  activity  which  was  indicated  by  high  value  of  its % IPCE.
Thermodynamic Properties and Characterizations of Chitosan Nano-Particles Corrosion Inhibition on The Surface of Mild Steelin Peat Water Media Maria Erna; Emriadi Emriadi; Admin Alif; Syukri Arief
ALCHEMY Jurnal Penelitian Kimia Vol 12, No 1 (2016): March
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.12.1.936.27-35

Abstract

The thermodynamic properties and characterizations of corrosion inhibition of chitosan nano-particles on the surface of mild steel in peat water media had been studied using weight loss method at temperatures of 30 - 50 oC. Steel surfaces were characterized by FT-IR spectra and SEM-EDS morphology photos. The research found that the value of DGo approaching -40 kJmol-1. The negative value of Gibbs free energy shows that the adsorption of inhibitor molecules on the surface of mild steel was achemisorption and it occurred spontaneously. Meanwhile, the values of DHo is also negative confirming that the adsoprtion of inhibitor molecules is an exothermic process. The value of DSo obtained is positive, it indicates hat the inhibitor molecules were adsorbed spontaneously on the mild steel surface. The analysis on mild steel surfaces hows that the nano-particle chitosan was adsorbed on the steel surface to form the complex compounds.
ANTIOXIDANT ACTIVITY OF CASHEW APPLE DREG EXTRACT AND THEIR EFFECT IN TRADITIONAL PROCESSING OF COCONUT OIL Yunita Arian Sani Anwar
ALCHEMY Jurnal Penelitian Kimia Vol 13, No 1 (2017): March
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.13.1.4172.17-28

Abstract

The aim of this study was to determine antioxidant activity of cashew apple dreg extract and their antioxidant activity in traditional processing of coconut oil. Cashew apple dreg was extracted by ethanol and fractionation by DCM, n-hexane and water. The antioxidant activity from dreg extract was determined using 2,2-diphenyl-1-pycrylhydrazil (DPPH). The result showed that all ethanol fractions of cashew apple dreg contain flavonoid and tannins/polyphenols. Based on scavenging DPPH all of ethanol fractions showed antioxidant activity. The greatest DPPH inhibition was observed for ethanol extract. On the contrary, n-hexane fraction showed the lowest IC50. Application in traditional processing of coconut oil showed that the addition 2,5% ethanol extract provide the best product according to the lower content of peroxide value and TBA number.
Pemurnian Parsial dan Karakterisasi Urease dari Biji Kacang Panjang (Vigna unguiculata subsp sesquipedalis L.) Zusfahair Zusfahair; Dian Riana Ningsih; Amin Fatoni; Darul Santri Pertiwi
ALCHEMY Jurnal Penelitian Kimia Vol 14, No 1 (2018): March
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.14.1.13000.72-83

Abstract

Urease merupakam enzim yang digunakan dalam hidrolisis urea menjadi amoniak dan asam bikarbonat dan telah banyak digunakan dalam proses industri. Tujuan penelitian adalah isolasi dan pemurnian urease dari kacang panjang serta karakterisasinya. Penelitian dimulai dengan melakukan perkecambahan biji kacang panjang selama 8 hari. Kecambah biji kacang panjang selanjutnya diekstraksi dengan menggunakan buffer fosfat pH 7 dan dipisahkan menggunakan sentrifugasi sehingga diperoleh ekstrak kasar urease. Ekstrak kasar urease selanjutnya difraksinasi menggunakan aseton pada tingkat konsentrasi 20, 40, 60 dan 80%. Fraksi yang mempunyai aktivitas spesifik paling tinggi selanjutnya dianalisis menggunakan metode SDS-PAGE untuk menentukan berat molekulnya dan dikarakterisasi lanjut meliputi: pengaruh suhu, pH, konsentrasi substrat dan penambahan ion logam terhadap aktivitas urease. Aktivitas urease ditentukan dengan metode Nessler. Hasil penelitian menunjukkan aktivitas spesifik urease dari kacang panjang paling tinggi ditemukan pada fraksi aseton (FA) 20. Hasil analisis berat molekul dengan metode SDS-PAGE diperoleh beberapa pita protein yang diduga berukuran sekitar 25 KDa dan 17 KDa. Kondisi optimum dari aktivitas urease diperoleh pada suhu 30 ºC, pH 7 dan konsentrasi urea 16,6 mM dengan nilai aktivitas 407,62 U/mL. EDTA dan ion logam dalam CaCl2, NaCl, NiCl2 dan CuCl2 pada variasi konsentrasi 10-3, 10-4  dan 10-5 M merupakan inhibitor urease FA 20 dari kacang panjang.Partial Purification and Characterization of Urease from Asparagus Bean (Vigna unguiculata subsp sesquipedalis L.). Urease is an enzyme used in urea hydrolysis to ammonia and bicarbonate acid and has been widely used in industrial processes. The study focused on isolation and purification of urease from asparagus beans and its characterization. The study was started with germination of asparagus beans for 8 days. Germinated asparagus beans were further extracted using phosphate buffer pH 7 and separated by centrifugation to obtain a crude extract of urease. The crude extract of urease was further fractionated using acetone at concentrations of 20, 40, 60 and 80%. The fraction with highest specific activity was then analyzed using SDS-PAGE method to determine its molecule weight and characterized further including the influence of temperature, pH, substrate concentration, and metal ion addition to urease activity. The urease activity was determined by the Nessler̕ s method. The results showed that the specific activity of urease from asparagus beans was found with highest activity in fraction of acetone (FA) 20. Analytical result using SDS-PAGE method was obtained some protein bands having molecular weights about 25 KD and 17 KDa. The optimum conditions of urease activity was obtained at 30 °C, pH 7, incubation time 20 min and urea concentration 16.6 mM with activity value 407.62 U/mL. EDTA and metal ions contained in CaCl2, NaCl, NiCl2 and CuCl2 at concentrations of 10-3, 10-4 and 10-5 M were FA 20 urease inhibitors.
Deteksi Kurkumin dan Bisdemetoksikurkumin dengan Teknik Voltammetri Menggunakan Elektrode Boron-Doped Diamond Wulan Tri Wahyuni; Latifah Kosim Darusman; Yuris Diksy
ALCHEMY Jurnal Penelitian Kimia Vol 14, No 2 (2018): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.14.2.19576.253-266

Abstract

Pada penelitian ini metode deteksi kurkumin dan bisdemetoksikurkumin dikembangkan dengan teknik voltammetri siklik menggunakan elektrode boron-doped diamond. Voltammogram siklik kurkumin dan bisdemetoksikurkumin dalam larutan elektrolit tetrabutilamonium heksafluorofosfat (TBAPF6)-asetonitril masing-masing menunjukkan 2 puncak oksidasi, yaitu pada potensial +0,4 V dan +1,9 V vs. Ag/AgCl untuk kurkumin, serta +0,6 V dan +2,0 V vs. Ag/AgCl untuk bisdemetoksikurkumin. Hubungan linear diperoleh antara konsentrasi kurkumin maupun bisdemetoksikurkumin dengan arus puncak oksidasinya. Hubungan linear  yang diperoleh adalah I(µA) = 8619,9C (M) + 0,7285 (R2=0,9995) dan I(µA) = 14658C (M) + 16,388 (R2=0,9299) berturut-turut untuk kurkumin puncak pertama dan kedua, serta I(µA) = 7953,2C (M) + 5,3977 (R2=0,9871) dan I(µA) = 5807,7 C (M) + 7,7616 (R2=0,9981) untuk bisdemetoksikurkumin puncak pertama dan kedua. Aplikasi metode yang dikembangkan terhadap sampel buatan yang mengandung campuran kurkumin dan bisdemetoksikurkumin menghasilkan 3 puncak oksidasi pada potensial +0,3 V, +1,2 V, dan +2,0 V vs Ag/AgCl mengindikasikan terjadinya tumpang tindih antara puncak kurkumin dan BDMC serta pergeseran puncak oksidasi. Nilai presisi pengukuran dengan metode yang dikembangkan ialah 15,86 dan 15,15% untuk kurkumin, serta 9,85 dan 31,47% untuk bisdemetoksikurkumin. Sementara nilai akurasi pengukuran ialah sebesar 96,69 dan 125,36% untuk kurkumin, serta 97,95 dan 127,54% untuk bisdemetoksikurkumin masing-masing berdasarkan puncak 1 dan 2. Hasil yang diperoleh menunjukkan performa analitik metode yang dikembangkan masih perlu ditingkatkan sebelum diaplikasikan untuk analisis kuantitatif.Detection of Curcumin and Bisdemetoxycurcumin by Voltammetric Technique using a Boron-Doped Diamond Electrode.  This study develops a cyclic voltammetry method for simultaneous detection of curcuminoid by using boron-doped diamond electrode. Curcumin and bisdemethoxycurcumin (BDMC) in tetrabutylammonium hexafluorophosphate (TBAPF6)-acetonitrile as electrolyte solution showed two oxidation peaks at +0.4 V and +1.9 V for curcumin, while those for BDMC appeared at +0.6 V and +2.0 V. Reduction peaks of both standards were not observed. In the optimum conditions, this method showed linear correlation between concentration of curcumin and BDMC with it’s oxidation peak current. The equations of I(µA) = 8619.9(C) (M) + 0.7285 (R2=0,9995) and I(µA) = 14658(C) (M) + 16.388 (R2=0.9299) were obtained for curcumin, I(µA) = 7953.2(C) (M) + 5.3977 (R2=0,9871) and I(µA) = 5807.7(C) (M) + 7.7616 (R2=0.9981) for BDMC. Meanwhile, the measurement of the artificial samples containing a mixture of curcumin and BDMC showed three oxidation peaks at +0.3 V, +1.2 V, and +2.0 V. This result indicated an overlapping between curcumin and BDMC peaks and peak shifting. Precision of the developed method was expressed as percent RSD, giving value of 15.86 and 15.15% for curcumin, and 9.85 and 31.47% for BDMC. The accuracy was 96.69 and 125.36% for curcumin, meanwhile for BDMC was 97.95 and 127.54% for peak 1 and 2. The result indicated that the method required further improvement before applied for quantitative analysis.
Process Technology Of Fabrication NO2 Gas Sensor Devices With Active Layer In2O3 Slamet Widodo
ALCHEMY Jurnal Penelitian Kimia Vol 10, No 1 (2014): March
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.10.1.11.69-86

Abstract

This paper discuss the design and fabrication of NO2 gas sensor based on metal oxide using thick film technology was described. The design of gas sensor is consisted of components, i.e. heater, electrode (interdigital fingers) and sensitive layer from In2O3 material. This sensor has been designed as multilayers with heater and both electrodes in one surface, in accordance with miniaturisation aspect, heat distribution and less consumption of energy from the sensor device. The heater and electrode were fabricated on alumina substrate (aluminum oxide/Al2O3) with silver paste. The In2O3 layer provides\ resistance change when it is exposed by NO2 gas. It indicates that this sensor device has a potency to be used as NO2 detector.
Reduction on The Levels of Tannins from Stevia Rebaudiana Extract Using Activated Carbon Triana Kusumaningsih; Nur Jannah Asrilya; Suci Wulandari; Dewi Restu Tri Wardani; Khoirul Fatihin
ALCHEMY Jurnal Penelitian Kimia Vol 11, No 1 (2015): March
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.11.1.111.81-89

Abstract

Extraction of tannins from leaves of Stevia rebaudiana using ethanol 30% with a temperature variation of 30, 50, 70 and 100oC for 3 hours was performed. Reduction on the levels of tannins in stevia extract is done by using activated carbon.               The results showed the greatest weight of the extract at 70oC is 1.008 g and extract relatively alkaline pH. Reduction on the levels of tannins on stevia extracts done by passing the extract of stevia in the burette containing activated carbon as much as 4 times the cycle. Tannin concentration was reduced by 39.74%.
Photocatalytic Reduction of Cu(II) Ion and TiO2-Catalyzed Paracetamol Photodegradation As An Alternative Method in Waste Treatment Devina Ingrid Anggraini; Eka Susanti Hp; Erliena Okta Guna Santosa
ALCHEMY Jurnal Penelitian Kimia Vol 11, No 2 (2015): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.11.2.726.163-174

Abstract

Recently, the issue of heavy metals are wastes is become popular such as Cu, Co, Pb, and etc. Furthermore, the presence of Cu together with paracetamol as pharmacy waste. Photocatalytic process could be an alternative to avoid the situation. This research investigated the influence of irradiation and the initial concentration of paracetamol toward TiO2-catalyzed photoreduction of Cu(II). The research aims to develop a photoreduction method that is catalyzed by TiO2 in the presence of paracetamol in reducing Cu(II) and paracetamol concentration. Cu(II) photoreduction process was (II) conducted in a close reactor equipped with a UV lamp. The remaining Cu(II) in solution was analyzed using Atomic Absorption Spectrophotometry (AAS) to determine its concentration and paracetamol concentration by visible spectrophotometry method. Results showed that the use of photocatalyst TiO2improves the photoreduction of  Cu(II), 15-45 minutes irradiation also contributes the increment, over the time a tiny decrease in photoreduction effectivity occur, however. At initial paracetamol concentration, 50 to 250 mg/L lead to an increase in photodegradation of paracetamol, and large decline occur over e.i. 250 mg/L,  however. The presence of paracetamol may increase the effectiveness of Cu(II) photoreduction due to the prevention of  radical OH• and electrons recombination. The most effective photoreduction of  25 mL solution of ion Cu(II) 10 mg/L is readily achieve in reaction conditions  using  20 mg of TiO2 by 45 minutes irradiation in the present of 25 mL of paracetamol 250 mg/L. By those Cu(II) ion was reduced by 98.87 % and 14.73 % of paracetamol was degraded.
Konduktivitas Apatit Lantanum Silikat La9.33Si6O26 Hasil Sintesis Hidrotermal dengan Mineraliser NaOH dan KOH Atiek Rostika Noviyanti; Dani Gustaman Syarif; Riansyah Amynurdin; Iwan Hastiawan; Iman Rahayu; Yati B. Yuliyati
ALCHEMY Jurnal Penelitian Kimia Vol 14, No 1 (2018): March
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.14.1.8468.1-15

Abstract

Apatit lantanum silikat banyak digunakan sebagai elektrolit pada sel bahan bakar padatan (SOFC). Beberapa oksida apatit lantanum silikat La9.33Si6O26 telah disintesis dengan metode hidrotermal guna mengamati pentingnya peranan mineraliser terhadap karakternya. Penelitian ini bertujuan untuk mengetahui pengaruh jenis dan konsentrasi mineraliser terhadap kristalinitas, ukuran partikel dan hubungannya dengan sifat konduktivitas oksida apatit lantanum silikat. Struktur, ukuran partikel dan konduktivitas oksida apatit masing-masing dikarakterisasi dengan XRD, PSA dan spektroskopi impedansi. Oksida apatit lantanum silikat diperoleh dengan melarutkan La2O3 dan Na2SiO3 dengan mol ratio 1,555 menggunakan mineraliser NaOH (3-5 M) dan KOH (0,3-0,7 M). Hasil penelitian menunjukkan bahwa kinerja elektrolit sangat ditentukan oleh kristalinitas dan morfologi apatit lanthanum silikat yang dipengaruhi oleh jenis dan konsentrasi mineralizer. Ukuran apatit lantanum silikat terkecil diperoleh dari hasil sintesis dengan menggunakan mineraliser NaOH 3 M yaitu 1,7889 µm, dengan nilai konduktivitas tertinggi yaitu 1,99×10-6 S/cm pada suhu operasi 600 ºC. Berdasarkan hasil tersebut NaOH 3 M merupakan mineraliser yang paling baik untuk menghasilkan apatit lanthanum silikat La9.33Si6O26.Conductivity of Lanthanum Silicate Apatite Phase of La9.33Si6O26 Prepared by Hydrothermal Synthesis using NaOH and KOH as Mineralizer. Lanthanum silicates are used as electrolytes in solid oxide fuel cells (SOFC). Some oxide-based apatite has been synthesized by hydrothermal method to observe mineralizer effect on the process of crystallization. The effect of type and amount of mineralizers for preparing apatite –type lanthanum silicate of La9.33Si6O26 was investigatedon its crystallinity, particle size, as well as on the conductivity properties relationship were investigated. The structure, particle size and conductivity of La9.33Si6O26 was characterized using X-ray diffraction, particle size analyzer and impedance spectroscopy respectively. The results show that the electrolyte performance is strongly dependent on the crystallinity and the morphology textural of lanthanum silicate apatite affected by the type and amount of mineralizer. The lanthanum silicate apatiteprepared by La2O3 and Na2SiO3 (molar ratio of La2O3 and Na2SiO3 = 1.555), and NaOH (3; 4; 5 M) and KOH (0,3-0,7 M) as mineralizer. As a result, apatite-type lanthanum silicate was prepare using NaOH 3 M shows smallest particle (1.7889 μm) and highest conductivity (1.99 × 10-6 S / cm at 600 ºC). With respect to both particle size and conductivity, the NaOH 3 M can be selected as a suitable type and amount mineralizer for the preparation of excellent lanthanum silicate apatite La9.33Si6O26.

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