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Polypyrrole (PPy) is widely regarded as a useful electrode material because it has the advantages of low cost, high electrical conductivity, and thermal stability. This study aimed to synthesize PPy membranes using polyphenol oxidase (PPO) isolated from white oyster mushrooms as a biocatalyst for processing textile wastewater. The membranes were produced through the electropolymerization of pyrrole (Py) using the electrodeposition method. The raw materials comprised 0.05 M Py and crude PPO white oyster mushroom extract at 35% v/v in citrate buffer pH = 6.8. The electrolysis process was performed at 6.00 V and 1.063–1.142 A using 16.57-48.97% immobilized PPO in PPy, PPO activity of 1.640–4.160 U, and 0.35 mM phenol as a substrate. The results showed that the use of the membrane in textile wastewater with a discontinuous flow caused a decrease of pH by 14.86%, phenol by 6.80%, Chemical Oxygen Demand (COD) by 81.30%, Biological Oxygen Demand (BOD) by 78.25%, and Total Suspended Solids (TSS) by 20.65%. Meanwhile, using the sample with a continuous flow caused a decrease of pH by 23.97%, phenol by 26.09%, COD by 88.50%, BOD by 78.00%, and TSS by 65.70%. The physical performance of membrane application to textile wastewater with discontinuous (flow rate = 48.19–51.50 L/h, flux = 3191.6–3387.5 L.m-2.h-1, and permeability = 319.2–338.7 Lm-2.h-1.bar) and continuous flow (flow rate = 48.19 L/h, flux = 3191.6 Lm-2.h-1, and permeability = 319.2 Lm-2.h-1.bar) was also assessed in this study. The Scanning Electron Microscopy (SEM) image was used to assess the morphology of the membrane before and after its application.

A microbial desalination cell (MDC) built on a modified surface has been studied for seawater desalination. The goal of this study is to provide and develop a seawater desalination system that does not require energy support by applying a modification of the anode as an electron acceptor. The different potential charges that occur between anode and cathode can serve as the driving force for electrodialysis of seawater, resulting in its desalination. Yeast has been applied as a biocatalyst and neutral red has been chosen as a redox mediator to facilitate the electron transport originating from the bioactivity of cells. Several types of surface modification have been conducted, i.e., biocatalyst-mediator immobilisation and electropolymerisation of neutral red at the anode surface. The optimisation of each device has been characterised by cyclic voltammetry and chronoamperometry. It has also been observed in a microbial fuel cell (MFC), prior to being functioned in the MDC. The concentrations of salt ion migration have been determined by ion exchange chromatography. This study found that the best configuration of a modified surface was obtained from carbon felt coated by polyneutral red film (CF/PNR); this generated the maximum value of all tested parameters: 42.2% of current efficiency; 27.11% of bio-devices efficiency; 92.5 mA m-2 of current density; and 61% of NaCl transport. Moreover, the modified surface could be a promising method for improving anode performance.

This research aims to make a polypyrrole (PPy) membrane and crude extract of polyphenol oxidase (PPO) as a membrane of mPPy/PPO apple extracts. The membrane of PPy/PPO-apple extract has been synthesized by the electrodeposition method. The electrolyte composition consists of a mixture of 0.10-0.20 M pyrrole (Py) and 50-100% PPO apple extract, which is stable using 50 mM of phosphate buffer solution at pH 6.80-7.00 and room temperature. The electrodeposition process is used 400 mesh steel gauze anode ST-304 and carbon plate cathode. Electrodeposition is carried out at potential = 5.00-6.00 V; current = 0.02-0.25 A; the distance from both electrodes = 1.00-2.00 cm for 300-500 seconds. The results from the deposition of PPy/PPO apple extract of the anode are a membrane of mPPy/PPO-apple extract, with total enzyme activity (U) = (957,1441, 2287 and 1754) using 2.00-5.00 mM phenol as a substrate which is measured based on the UV-visible spectrophotometric method. PPy and mPPy/PPO-apple extracts were characterized by SEM and SEM-EDS. The membrane of mPPy/PPO-apple extract can be used to remove phenol in industrial wastewater samples is 50-65% with a filtration capacity of 500 mL for 2 hours.

Polypyrrole (PPy) is widely regarded as a useful electrode material because it has the advantages of low cost, high electrical conductivity, and thermal stability. This study aimed to synthesize PPy membranes using polyphenol oxidase (PPO) isolated from white oyster mushrooms as a biocatalyst for processing textile wastewater. The membranes were produced through the electropolymerization of pyrrole (Py) using the electrodeposition method. The raw materials comprised 0.05 M Py and crude PPO white oyster mushroom extract at 35% v/v in citrate buffer pH = 6.8. The electrolysis process was performed at 6.00 V and 1.063-1.142 A using 16.57-48.97% immobilized PPO in PPy, PPO activity of 1.640-4.160 U, and 0.35 mM phenol as a substrate. The results showed that the use of the membrane in textile wastewater with a discontinuous flow caused a decrease of pH by 14.86%, phenol by 6.80%, Chemical Oxygen Demand (COD) by 81.30%, Biological Oxygen Demand (BOD) by 78.25%, and Total Suspended Solids (TSS) by 20.65%. Meanwhile, using the sample with a continuous flow caused a decrease of pH by 23.97%, phenol by 26.09%, COD by 88.50%, BOD by 78.00%, and TSS by 65.70%. The physical performance of membrane application to textile wastewater with discontinuous (flow rate = 48.19-51.50 L/h, flux = 3191.6-3387.5 L.m-2.h-1, and permeability = 319.2-338.7 Lm-2.h-1.bar) and continuous flow (flow rate = 48.19 L/h, flux = 3191.6 Lm-2.h-1, and permeability = 319.2 Lm-2.h-1.bar) was also assessed in this study. The Scanning Electron Microscopy (SEM) image was used to assess the morphology of the membrane before and after its application. [ABSTRACT FROM AUTHOR]

Tujuan dari penelitian ini adalah untuk mengkaji pengaruh lama aktivasi terhadap perubahan struktur kimia dan mutu arang aktif. Arang aktif dibuat di dalam retor baja tahan karat yang dilengkapi dengan pemanas listrik pada suhu 850ºC dengan lama waktu reaksi 30, 60, 90 dan 120 menit dengan menggunakan uap air sebagai bahan pengaktif. Evaluasi strukur kimia arang aktif dilakukan dengan menggunakan spektrofotometri inframerah (FTIR), X-ray difraksi (XRD) dan elektron mikroskop (SEM). Mutu arang aktif terbaik dihasilkan pada arang yang diaktivasi selama 90 menit. Rendemen yang dihasilkan sebesar 13,75%, kadar air 3,03%, abu 23,57% zat terbang 11,12%, karbon terikat 65,31%. Daya serap terhadap iodin sebesar 1003,9 mg/g, benzena 19,10%, formaldehida 40,55% dan metilina biru 282,19 mg/g. Mutu arang aktif yang dihasilkan ini, terutama apabila dilihat dari besarnya daya serap terhadap iodin dan metilina biru memenuhi persyaratan Standar Indonesia. Hasil pengkajian struktur arang aktif dengan menggunakan XRD menunjukkan tinggi (Le) dan jumlah (N) lapisan aromatik meningkat dengan makin lamanya waktu aktivasi, sedangkan lebar (La) lapisan aromatik dan kristalinitasnya (X) menurun dengan jarak antar lapisan (d) stabil. Hasil analisis FTIR menunjukkan bahwa permukaan arang aktif mengandung ikatan C-0 dan C-B, dan hasil analisis SEM menunjukkan jumlah dan diameter pori meningkat dengan makin lamanya waktu aktivasi dan didominasi oleh makropori.

Tulisan ini membahas struktur arang dari lignin pada suhu karbonisasi yang berbeda. Proses pembuatan arang lignin dilakukan pada suhu 200, 300, 400, 500, 650, 750 dan 850°C dalam suatu retort yang terbuat dari baja tahan karat yang dilengkapi dengan pemanas listrik Untuk mengetahui perubahan struktur arang yang terjadi dilakukan analisis dengan menggunakan FTIR, XRD dan SEM. Hasil analisis XRD menunjukkan bahwa jarak antar ruang lapisan aromatik (d) dan lebar lapisan aromatik (La) menurun dengan makin meningkatnya suhu karbonisasi, sedangkan untuk tinggi lapisan aromatik (Lc), derajat kristalinitas (X) dan jumlah lapisan aromatik (N) meningkat dengan makin naiknya suhu karbonisasi. Spektrum FTIR dari arang lignin menunjukkan bahwa antara suhu 300-500°C terjadi perubahan struktur kimia dari bahan baku secara nyata. Ikatan OH, dan C=C alifatik menurun dengan naiknya suhu, sedangkan struktur eter dan aromatik makin berkembang. Pada suhu 850°C arang yang dihasilkan mempunyai struktur aromatik yang permukaannya mempunyai gugus C-O-C, C=O dan C- H. Analisis SEM menunjukkan bahwa jumlah dan diameter pori arang meningkat dengan makin naiknya suhu karbonisasi. Kualitas arang yang baik diperoleh pada suhu karbonisasi 500°C yang menghasilkan derajat kristalinitas sebesar 33,90 %, tinggi lapisan aromatik 3.21 nm, lebar lapisan aromatik 10,96 nm, jumlah lapisan aromatik 8,67, jarak antar lapisan aromatik d(002) = 0,35 nm dan d(100) = 0,21 nm dengan diameter pori arang antara 12,6 mm. Arang ini mempunyai sifat keteraturan yang tertinggi, permukaannya bersifat polar, kaku, keras dan struktur porinya makropori

The characterization of activated charcoal from steam activation of sengon (Paraserianthes falcataria) wood is reported in this paper. The purpose of this investigation was to study the influences of temperature and concentration of chemical activator on the activated charcoal yield and its quality. The activated charcoal was produced in a stainless steel retort with electrical heater at the temperature of 7000C, 8000C and 9000C and for activation used NH4HCO3 with its consentration 0,5; 1,0; 3,0; 5,0 and 10% respectively. The best quality of the activated charcoal produced when the activation temperature was 9000C with the NH4HCO3 1,0 %. The yield of activated charcoal was 5,90%, moisturecontent 6,39 %, ash content 9,15 %, volatile matter 8,81 %, fixed carbon 82,04 %. Adsorptive capacity of iodine was 1154,4 mg/g, NH3 25,08 %, CHCl3 42,28 %, CCl4 51,74 %, benzene 49,10% and methylene blue 138,80 - 319,00 mg/g. Surface area was 1143,7 m2/g. The most abundance of particle size was 4,00 - 5,65 micron and pore volume 16,00 - 22,62 micron. High and diameter pore was 37,49 and 22,52 micron.

Penelitian nano teknologi dalam ranah hasil hutan dapat dieksploitasi dari lignoselulosa menjadi nano karbon. Penelitian ini bertujuan untuk mendapatkan struktur nano karbon yang potensial sebagai material bioenergi atau biosensor. Kayu jati dan bambu dikarbonisasi pada suhu 400-500oC, arang yang dihasilkan diaktivasi secara kimia dan fisika pada suhu 800oC selama 60 menit. Dari proses ini dihasilkan arang dengan derajat kristalinitas dan luas permukaan tinggi. Setelah pemurnian dan aktivasi, arang aktif yang dihasilkan dimasukkan logam Ni dan Zn yang kemudian dipanaskan secara vakum mengunakan spark plasma pada suhu 1300oC. Karbon yang dihasilkan diuji struktur dan sifatnya menggunakan perangkat Pyrolysis Gas Chromatography Mass Spectrometer, Scanning Electron Microscope-Energy Diffraction Xray Spectrometer, X-ray Diffractometer, I-V meter dan potensiometer. Hasil penelitian menunjukkan arang aktif terbaik dihasilkan dari aktivasi kimia-fisik (KOH uap air) menghasilkan kadar karbon 84,29%; luas permukaan 850,5 m2/g, derajat kristalinitas 38,99% dan hambatan sebesar 0,10. Sifat arang aktif kayu jati yang dimasukkan logam Ni dengan perbandingan 1:5 menghasilkan sifat terbaik dengan derajat kristalinitas 73,45% dan konduktivitas sebesar 433,86 S/m. Arang aktif jati hasil pemanasan vakum menghasilkan derajat kristalinitas sebesar 78,29% dengan pola I-V meter berbentuk sigmoid dan respon potensiometer berbentuk slope mendekati faktor Nerst. Nano karbon dari lignoselulosa kayu jati yang dihasilkan bersifat semikonduktor dan lebih sesuai digunakan sebagai biosensor.

In this work, the oligomer of 4-vinylpyridine designated as O(4-VP) was synthesized by hydrogen peroxide initiated chain growth polymerization and characterized in terms of molecular weight and structure by matrix assisted laser desorption ionization time of flight mass spectroscopy (MALDI-TOF MS). The oligomer was tested as corrosion inhibitor of mild steel in brine solution saturated with carbon dioxide, with the main purpose to investigate the effect of inhibitor concentrations and temperatures on the inhibition activity defined in terms of corrosion rate and percent of protection. The inhibition tests were carried out using the methods of weight loss (WL) and linear polarization (LP). Characterization using MALDI-TOF MS revealed that the oligomer has the mass (m/z) in the range 200-2400, which corresponds to chain length of 2-22 repeating units. The results of corrosion rate measurements show that the corrosion rate with the use of oligomer is significantly lower than that without inhibitor, demonstrating that the oligomer functioned as effective corrosion inhibitor, while the 4-vinyl pyridine monomer was found to promote the corrosion. It was also found that the protection by the oligomer increased with increasing temperature and it was predicted the oligomer was chemically adsorbed by the surface of the metal.

Nano teknologi di bidang hasil hutan yang dapat dikembangkan di antaranya adalah nano karbon dari lignoselulosa. Bahan baku utamanya adalah atom karbon yang berasal dari arang hasil karbonisasi lignoselulosa. Bahan baku yang digunakan adalah jati yang dikarbonisasi pada suhu 400-500 °C, arang yang dihasilkan kemudian dilanjutkan dengan diaktivasi pada suhu 800 °C selama 60 menit dengan uap air dan kalium hidroksida (KOH) 15% sebagai aktivator. Proses selanjutnya dilakukan interkalasi dengan logam nikel dan di karbonisasi lagi pada suhu 900 °C selama 60 menit. Kualitas dan struktur karbon dievalusi menggunakan Pirolisis-gas kromatografi mass spectrofotometri (Py-GCMS), skening electron mikroskop-energi diperse spektrofotometer (SEM-EDS), X-ray difraktometer (X-RD). Arang aktif yang dihasilkan juga di uji sifat fisika dan kimianya. Biosensor dibuat dengan sistem moleculary imprinted polimer (MIP) berbasis elektroda pasta karbon dan optimasinya. Hasil penelitian menunjukkan bahwa nano karbon dari lignoselulosa dapat dibuat biosensor dengan sistem moleculary imprinted polimer (MIP). Formula optimum yang dihasilkan terdiri dari campuran 15% MIP, 45% karbon dan 40% parafin yang menghasilkan faktor nernst sebesar 49,7 mV/dekade dan limit deteksi sebesar 1,02 x 10-6 M pada pH optimum 4.

Penyelidikan kimia telah dilakukan untuk pertama kalinya terhadap tumbuhan Litsea cassiaefolia. Pada penyelidikan ini, melalui kombinasi kromatografi partisi dan cara pemisahan yang lazim, tiga alkaloid telah ditemukan, yakni disentrin (I), dehidrodisentrin (II), dan disentrinon (III), masing-masing termasuk alkaloid benzilisokuinolin jenis aporfin, dehidroaporfin, dan oksoaporfin. Karakterisasi ketiga alkaloid tersebut dilakukan berdasarkan data spektroskopi UV, 1H-NMR, 13C-NMR, dan massa. Di antara ketiga senyawa tersebut, disentrin (I) merupakan alkaloid utama yang ditemukan dengan kadar yang cukup tinggi; oleh karena itu, sifat biologi senyawa ini diselidiki lebih lanjut. Ditemukannya ketiga alkaloid dalam tumbuhan ini sangat berguna sebagai dasar kajian kemotaksonomi. The first chemical study on Litsea cassiaefolia had been carried out in our laboratory. In this investigation, by combination of partition chromatography and common separation methods, three alkaloids had been isolated, namely dicentrine (I), dehydrodicentrine (II), and dicentrinone (III), which belong to benzylisoquinoline alkaloids of the types aporphine, dehydroaporphine, and oxoaporphine, respectively. The characterization of the alkaloids had been based upon the UV, 1H-NMR, 13C-NMR and mass spectroscopic evidence. Among these compounds, dicentrine (I) is the major alkaloid which may be isolated in relatively higher yield, thus, the biological property of this compound is being further investigated. Finding the alkaloids in this plant is beneficial as a basis for chemotaxonomy.

The first chemical investigation on Litsea excelsa had been carried out in our laboratories. Three alkaloids had been isolated in this investigation, namely dicentrinone (I), nordicentrine (II), and norpredicentrine(III), and their identities were established through UV, 1H-NMR, 13C-NMR, and mass spectral evidence. Based on the co-occurrence of these three alkaloids in the single plant, a biogenetic oxidative sequence of these compounds may be proposed. This work will be of value for chemotaxonomy of the genus Litsea in particular, the Lauraceae in general. Penyelidikan kimia telah dilakukan untuk pertama kalinya terhadap tumbuhan Litsea excels. Tiga alkaloid telah ditemukan pada penyelidikan ini, yakni disentrinon (I), nordisentrin (II), dan norpredisentrin (III). Identitas ketiga senyawa ini ditetapkan berdasarkan data spektroskopi UV, 1H-NMR, 13C-NMR, dan spectrum massa. Dengan ditemukannya ketiga alkaloid secara bersama-sama dalam satu spesies tumbuhan ini, maka tahap oksidasi biogenesis ketiga senyawa dapat disarankan. Hasil penelitian ini berguna untuk kemotaksonomi genus Litsea khususnya, famili Lauraceae umumnya.

Perkembangan ilmu pengetahuan abad ini dan yang akan datang sudah memasuki teknologi nano. Di bidang hasil hutan, teknologi nano yang dapat dikembangkan di antaranya adalah nano karbon dari bahan berlignoselulosa. Tujuan penelitian ini adalah menyediakan informasi dan teknologi pengolahan arang sebagai bahan baku nano karbon dari bahan lignoselulosa. Bahan baku lignoselulosa yang digunakan dalam penelitian ini adalah kayu jati, dan bambu yang dikarbonisasi pada suhu 400-500°C menggunakan kiln drum, arang yang dihasilkan dimurnikan dengan jalan dipanaskan pada suhu 800°C selama 60 menit yang sebelumnya didoping dengan logam Zn, Ni dan Cu. selanjutnya dihaluskan menggunakan high energy mechanic (HEM) selama 48 jam. Arang dengan kristalinitas tinggi disintering menggunakan spark plasma pada suhu 1.300°C. Karbon yang dihasilkan diuji sktuktur dan sifatnya menggunakan Py-GCMS, SEM-EDX, XRD,dan sifat elektrik. Hasil penelitian menunjukkan struktur karbon yang terbaik dihasilkan dari arang jati yang dikarbonisasi pada suhu 800°C yang didoping dengan atom Ni pada perbandingan 1:5 yang menghasilkan derajat kristalinitas sebesar 78,98% resistensi (R) 0,17Ω, konduktivitas 175,52 Ω-1m-1. Kualitas nano karbon setelah disintering derajat kristalinitasnya menjadi 81,87%, resistensi (R) 0,01Ω, dan konduktivitasnya sebesar 1067,26 Ω-1m-1. Nano karbon yang dihasilkan dapat dibuat sebagai biosensor, biobatere dan bioelektroda. Sehingga diperlukan penelitian lebih lanjut.

Preliminary study of preparation reference material for trigonelline determination in green coffee beans have been performed by HPTLC method. Physical characterization performed on green coffee beans include the determination of moisture content, ash content and metal content. Water content values obtained on average 6.4% (%RSD 4.8) and ash content 3.9% (%RSD 16.2). Metal determination (Cu, Zn, Fe) with atomic absorption spectrometry method found Cu 9.4 (mg/kg), Zn 12,0 (mg/kg) and Fe 64.0 (mg /kg). Sonication as extraction method using methanol solvent for 30 minutes and separation method HPTLC on aluminum plates coated with silica gel 60 F254. Eluent used was mixture of n-propanol: methanol: water (4:1:4, v/v/v) with elution length 8 cm. Linear regression obtained in concentration range 200-1200 ng spot-1 with R2 = 0.9857. Detection limits obtained 140.7 ng and 468.9 ng for quantitation limit. Repeatability was achieved from 800 ng spot-1 (% RSD 13.8). Keywords : Reference material, Trigonelline, green coffee, HPTLC

ABSTRAK Telah dilakukan penelitian penentuan diazinon dari sampel tanah pertanian di beberapa kecamatan Kabupaten Nganjuk Jawa Timur menggunakan elektroda kerja tembaga amalgam padat (CuSAE) secara diferensial pulsa voltametri (DPV) dibandingkan dengan metode kromatografi. 100 g sampel tanah pertanian yang dihaluskan dengan ukuran 100 mesh diekstraksi menggunakan aseton. Ekstraksi dilakukan menggunakan ekstraktror soxhlet dengan 10 kali sirkulasi. Hasil ekstraksi sebagian ditambahkan surfaktan SDS untuk dianalisis secara voltametri menggunakan elektroda CuSAE dan sebagian dianalisis menggunakan kromatografi cair kinerja tinggi (HPLC). Analisis voltametri dilakukan pada pH 3 dengan elektrolit pendukung CaCl 2 menggunakan standar adisi, sedangkan analisis dengan HPLC menggunakan grafik standar. Berdasarkan data voltamogram dan kromatogram yang telah diolah dengan program origin 7.0 menghasilkan perolehan kembali rata-rata diazinon (97.40 ± 1.02) % pada voltametri dan (100.98 ± 7.10) % pada HPLC. Analisis diazinon kedua metode dibandingkan dengan uji t (t hitung = 0.4785 < t tabel = 2.31) sehingga tidak ada perbedaan hasil antara metode voltametri dan HPLC. ABSTRACT The research has been done for determination of diazinon in agricultural soil samples from several districts n Nganjuk, East Java . Solid copper amalgam (CuSAE) used as a working electrode using differential ulse voltammetry (DPV) compared with chromatographic method. Around 100 g sample of agricultural soil ith a size 100 mesh was extracted using 100 ml acetone. The extraction was done using extractor oxhlet with 10 times the circulation. A part of the extraction yield was added SDS surfactant for analysis by DPV, and another part analyzed by using high performance liquid chromatography (HPLC). Voltammetric analysis carried out at pH 3 with CaCl2 as a supporting electrolyte using standard addition method, while the analysis by HPLC using calibration curve (standard graphic).Based on the data from voltammograms and chromatograms after processing data using Origin 7.0 programme, the average of recovery of diazinon found to be 97.40 ± 1.02 % and 100.98 ± 7.10 % using voltammetry and HPLC methods, respectively. The results from both of methods compared using t test (t count = 0.4785 < ttable = 2.31). Therefore, there is no difference between the results from voltammety method compared with HPLC method.

Penelitian ini bertujuan untuk mengkaji pembuatan elektroda termodifikasi film polipirol-lisin dan penerapannya untuk sensor potensiometrik lisin. Polipirol-lisin dilapiskan pada permukaan elektroda Pt dengan metode elektropolimerisasi dalam larutan air yang mengandung L-lisin HCl dan ion ClO pada pemindaian potensial 0 – 1.100 mV terhadap elektroda Ag/AgCl sebanyak 50 siklus. Kondisi optimum elektroda tipe kawat terlapis polipirol-lisin diperoleh pada komposisi pirol/lisin/ClO 0,05/0,05/0,1 M. Spektrum FTIR telah direkam dan menunjukan lisin terimobilisasi dalam film polipirol. Elektroda yang dibuat menunjukkan perilaku Nernstian dengan kemiringan 56,91± 1,75 mV per dekade (per 10 mV) pada daerah linier 10-3– 10-1 M, batas deteksi 10M lisin, waktu respon pada konsentrasi daerah linier dari 120 - 60 detik. Pemakaian selama 20 hari menunjukkan respon yang relatif konstan. Kedapatulangan elektroda cukup bagus ditunjukkan dengan koefisien variansi (%KV) sebesar 3,06.

Electropolymerization processes of pyrrole and the usage of polypyrrole membrane as lysine and alanine deliverance have been studied by cyclic voltammetry technique. Polypyrrole membrane was prepared by electropolymerization processes of pyrrole in water based solvent containing sodium perchlorate as supporting electrolyte. Electropolymerization processes were carried out within potential range of 0-1100 mV vs Ag/AgCl reference electrode and at the scanning rate of 100 mV/s. In this study, lysine and alanine have been used as molecules which could easily be loaded on and released from polypyrrole membrane. The presence of lysine or alanine during electropolymerization process reduced the rate of electropolymerization of polypyrrole. In lysine or alanine transfer processes into polypyrrole membrane, the interaction between polypyrrole and lysine or alanine showed by the curve of E½ oxidation in respect of - log C. It proved that the E½ oxidation shifted to more positive potential showed by the increasing of concentration of lysine or alanine. Beside that, voltammetric responses of lysine and alanine transfered into polypyrrole membrane were found to be Nernstian. The results indicated that polypyrrole could be used as a sensor of lysine and alanine. Keywords: Electropolymerization, polypyrrole membrane, voltammetry technique

This paper describes a reverse-phase high performance liquid chromatographic (HPLC) method for the separation, identification and quantification of vanillin in ethanolic extracts of cured vanilla. The fresh green beans were cured by three methods: scalding in hot water, drying in the oven, and drying in the sun. Two treatments for the cured beans before extraction, there were cutting cured vanilla about 2.5 cm and not cutting. The extraction was with Soxhletation and percolation method in 99.9 % ethanol. The vanillin was separated on C18 column using a mobile phase gradient of methanol - acidified water (10-90), detection at 280 nm. The HPLC technique allows a more accurate means of determining the vanillin content of vanilla than the spectrophotometric method . Keywords: Vanilla planifolia Andrews, Vanillin, HPLC

Electropolymerization processes and electrochemical properties of polypyrrole as electroactive polymer have been studied by cyclic voltammetric technique. Pyrrole was electropolymerized to form polypyrrole in water-based solvent containing sodium perchlorate as supporting electrolyte in several pH values. The pH of the solutions were varied by using Britton Robinson buffer. The results showed that oxidation potential limit of electropolymerization processes of pyrrole was 1220 mV vs Ag/AgCl reference electrode. It can be seen that cyclic voltammetric respon of polypyrrole membrane that was prepared by electropolymerization processes of pyrrole at the scanning rate of 100 mV/s was stable. While the processes of pyrrole electropolymerization carried out at the variation of pH showed that the best condition was at the pH range of 2 - 6. Keywords: polypyrolle, electropolymer, voltammetric technique

A conducting polymer, polypyrrole, has been electrochemically synthesized from pyrrole monomer using cyclic voltammetry technique in aqueous solution in the presence of HDS dopant and KNO3 supporting electrolyte. The polymer was deposited on the surface of an Au-wire and the modified electrode obtained was then used as dodecylsulfate (DS-) ion sensor electrode. The best performance PPy-DS modified-Au electrode conditioned in the air system without HDS or SDS solution gave linear potential response for the concentration range of 1.0 x 10-5 - 1.0 x 10-3 M, sensitivity of 54.5 mV/decade, detection limit of 1.0 x 10-5 M, and response time of 23 - 30 second. The electrode showed good selectivity towards other anions, therefore can be used to determine SDS concentration in real samples system without any change of the samples matrix. Keywords: polypyrrole, SDS, cyclic voltammetry

Extraction of silver (I) has been studied from black/white printing photographic waste by emulsion liquid membrane technique. Composition emulsion at the membrane phase was cerosene as solvent, sorbitan monooleat (span 80) as surfactant, dimethyldioctadesyl-ammonium bromide as carrier and as internal phase was HNO3. Optimum condition was obtained: ratio of internal phase volume and membrane phase volume was 1:1 : concentration of surfactant was 2% (v/v) : time of making emulsion was 20 second : rate of stiring emulsion was 1100 rpm : rest time emulsion was 3 second : rate of emulsion volume and external phase volume was 1:5 : emulsion contact rate 500 rpm : emulsion contact time was 40 second : concentration of silver thiosulfate as external phase was 100 ppm : pH of external phase was 3 and pH of internal phase was 1. Optimum condition was applied in silver(I) extraction from black/white printing photographic waste. It was obtained 77.33% average which 56.06% silver (I) average of internal phase and 22.66% in the external phase. Effect of matrices ion decreased silver(I) percent extraction from 96,37% average to 77.33% average. Keyword: photographics waste, silver extraction

A capillary electrophoretic (CE) analysis with ultra-violet (UV) detection was performed for further separation of low-molecular-mass (LMM) calcium species in phloem sap of Ricinus communis L. Two different background electrolytes (BGE) were used for the separation; these are (1) hydrogen phosphate/dihydrogen phosphate buffer containing cetyltrimethylammonium bromide (CTAB) as an electro-osmotic flow (EOF) modifier, and (2) boric acid buffer containing CTAB. Various parameters affecting the analysis, including the composition and pH of the BGE were systematically studied. The sensitivity, resolution, baseline noise, migration time of the species peaks, and reproducibility of the method were evaluated under optimised condition. At least 13 UV-active species were optimally separated within about ten minutes. The optimised measurement condition was also achieved using 10 mM hydrogen phosphate/10 mM dihydrogen phosphate containing 0.5 mM CTAB at pH 8.0 as BGE, and by applying voltage of ‑20 kV and temperature of 14°C. Evidently, the analytical method was successfully used for the separation of LMM calcium species in phloem sap of R. communis L. Keywords: capillary electrophoresis, calcium species, phloem sap, Ricinus communis

The determination of Sn(II) ion at trace levels using integrated gas-liquid separator-reactor with hydride generation-quartz furnace atomic absorption spectrophotometer (HG-QFAAS) has been done. This modified gas-liquid separator at various sizes was able to increase sensitivity in the determination of Sn(II) in solution. The acid reagent mixing techniques, sample and reductant optimally occurs in a coil reaction before they are going to the gas-liquid separators. The optimum conditions of parameter measurement in the determination of Sn ion with HG method are influenced by type and concentration of acid, and the concentration of reductant has been evaluated. This optimum parameters can increase of analytical performance simultantly, which is shown by detection limit 3.74 mg L-1 for 100 mL injection volume (3.74 pg Sn). The accuracy of measurement shown by the % recovery of the Sn determination in natural water sample at > 95%, indicate this technique is good to be applied for tin analysis at picogram level. Keywords: Sn, hydride generation, gas-liquid reactor separator, QFAAS

The aim of this research is to study the effect of concentration carrier, pH and time of extraction on separation's factor of penicillin g - phenyl acetate by reactive extraction technique. The 10 mL aqueous solution with variation of pH : 5, 6 contains 0.001 M penicillin G and 0.001 M phenyl acetate has been extracted with 10 mL n-butyl acetate contains dioctylamine as carrier. Variation concentration of carrier were 0.000; 0.002; 0.004; 0.006 and 0.008 M. Variation time of extraction were 1, 5, 10, 15 and 20 min. The penicillin G and phenyl acetate that dissolved in organic phase ha been reextracted with 10 mL aqueous with variation of pH : 7, 8. The optimum condition obtained as follow : concentration dioctylamine was 0.002M ; pH the first phase water was 5 and the second phase water was 8 ; and the time of extraction was 10 min. Keywords: Separation factor, Reactive extraction

The research was conducted to know the influence of methanol extracts from 19 plant species to the second-stage juvenil (J2) mortality and to the hatching of the potato cyst nematode, Globodera rostochiensis, the new pest of potato in Indonesia. The research was conducted by using complete random design, where each treatment was repeated 3 times. Cyst hatching was conducted by using ZnSO4 10-2 M. Data obtained to be analyzed with the ANOVA and continued with the DMRT 5%. The result indicated that from 19 species of examined plant, clove flower and leaf methanol extract with concentration 10.000 ppm inflicted 100% and 96,7% J2 mortality and others inflicted

Telah dilakukan penelitian ekstraksi La(III), dengan fasa organik senyawa pengemban tributyl phosphate (TBP) dan di(2-etylhexyl) phosporic acid (D2EHPA) yang dilarutkan dalam kerosene. Ekstraksi dilakukan dengan variasi pH, konsentrasi senyawa pengemban, dan kekuatan ion (nitrat). Pemantauan konsentrasi logam lantanum di fasa air dilakukan secara spektrofotometri UV-Vis dengan menggunakan natrium alizarin sulfonat (NAS) sebagai senyawa pembentuk wama dan diukur pada panjang gelombang 528 nm. Senyawa pengemban D2EHPA dalam transpor logam lantanum memperlihatkan keterlibatan ion hidrogen, tetapi tidak untuk nitrat. Hal ini berlawanan dengan TBP. Campuran TBP dan D2EHPA dengan perbandingan 0,2 M:0,8 memperlihatkan sifat yang mengikuti komponen utamanya (D2EHPA). Senyawa pengemban campuran TBP-D2EHPA memberikan efek sinergi dengan bertambahnya fraksi mol D2EHPA Proses stripping (pemisahan/recovery) dipelajari dengan membandingkan pH fasa penerima 1 dan 3 sedangkan pH larutan air (fasa umpan) adalah 3 Pada pH fasa penerima 1 recovery La yang diperoleh jauh lebih baik daripada pH 3

Telah dilakukan penelitian tentang mekanisme transpor logam lantanum melalui membran cair berpendukung (SLM). Sebagai membran pendukung digunakan politetrafluoroetilen (PTFE) yang diaktifkan dengan cara merendamnya dalam campuran senyawa pengemban asam di-2-etilheksilfosfat (D2EHPA) dan tributilfosfat (TBP) dengan pelanit kerosene. Efek sinergi antara kedua senyawa pengemban tersebut dipelajari dengan SLM. Pemantauan konsentrasi logam lantanum di fasa air dilakukan secara spektrofotometri UV-Vis dengan menggunakan natrium alizarin sulfonat (NAS) sebagai senyawa pembentuk warna dan diukur pada panjang gelombang 528 nm. Transpor melalui SLM dipengaruhi oleh gradien konsentrasi, yaitu pH, kekuatan ion, serta senyawa pengemban. Transpor logam lantanum dengan senyawa D2EHPA memperlihatkan keterlibatan ion hidrogen, dan tidak untuk ion nitrat. Hal ini berlawanan dengan TBP. Sedangkan transpor dengan campuran kedua pengemban (perbandingan 0,2 MTBP 0,8 M D2EHPA) memperlihatkan sifat seperti komponen utamanya (D2EHPA). Senyawa pengemban campuran TBP-D2EHPA memberikan efek sinergi denganbertambahnya fraksi mol D2EHPA.

Oleic imidazoline is one of the nitrogen containing heterocyclic compounds that has been widely used as commercial corrosion inhibitor, especially in minimizing the carbon dioxide induced corrosion process in oilfield mining. In this present work, some imidazoline derivative compounds have been synthesized utilizing both conventional and microwave assisted organic synthesis (MAOS) methods, in order to determine their corrosion inhibition properties on carbon steel surface. The MAOS method is more effective in synthesizing these compounds than the conventional method regarding to the higher chemical yields of products (91% to 94%) and the shorter reaction times (7 to 10 minutes). The characterization of corrosion inhibition activities of the synthesized products towards carbon steel in 1% NaCl solution was determined by the Tafel plot method. The corrosion inhibition activities of compound 1b ((Z)-2-(2-(heptadec-8-enyl)-4,5-dihydroimidazol-1-yl)ethanamine), 2b ((Z)-2-(2-(heptadec-8-enyl)-4,5-dihydroimidazol-1-yl)ethanol) and 3b (2-(2-heptadecyl-4,5-dihydroimidazol-1-yl)ethanamine) at 8 ppm concentration in 1% NaCl solution are, respectively, 32.18%, 39.59% and 12.73%. The heptadec-8-enyl and hydroxyethyl substituents at C(2) and N(1) position of imidazoline ring, respectively, gave the most effective corrosion inhibition activity towards carbon steel compared to the presence of other substituents. The increase in concentrations of compound 1b, 2b and 3b in 1% NaCl solution tends to improve their corrosion inhibition activities. Based on the analysis of the free Gibbs adsorption energy (ÄG0ads) values of compound 1b, 2b and 3b (-32.97, -34.34 and -31.27 kJ/mol, respectively), these compounds have the potential to interact with carbon steel through semi-physiosorption or semi-chemisorption.