Effect of Stirring Time on Sodium Silicate Synthesis From Mount Kelud Volcanic Ash

This study performed the synthesis of sodium silicate from the volcanic ash of Mount Kelud with various stirring time in the sodium silicate synthesis process. Synthesis of sodium silicate was carried out using alkaline extraction at low temperature. This method is based on the solubility of silica under alkaline conditions and is proven to be more effective than the smelting method. The dissolution of silica contained in the volcanic ash of Mount Kelud was carried out using NaOH solution to form a Na2SiO3 solution. This process also studied the effect of stirring time on the amount of dissolved silica, with the stirring time of 0.5; 1; 1.5; 2; 2.5; 3 and 4 hours. The dissolved silica levels were tested using AAS. The amount of dissolved silica increased sharply with the longer length of stirring time, however for a stirring time of more than 2.5 hours, the dissolution was slow. The study revealed that the optimal result time was obtained from the stirring time of 2.5 hours with dissolved silica content of 19.82%. Keywords: volcanic ash, silica, sodium silicate, stirring time

Analisis Sidik Jari Kromatografi Lapis Tipis Tanaman Anting-Anting (Acalypha indica L.)

Anting-anting plant (Acalypha indica L.) is a plant that the community has used as raw material for herbal medicine. Anting-anting plants contain chemical compounds, so it is difficult to ensure these plants' safety and quality control. The research objective was to validate the method by knowing the stability, specificity, precision, and rigidity of the chromatographic profile of alkaloid compounds in the TLC analysis of the anting-anting extract. Extraction was carried out using ethyl acetate solvent for 20 minutes with a frequency of 42 kHz. The eluent used is cyclohexane: toluene: diethylamine (75:15:10) with Dragendorff reagent. The method of validation was acceptable according to the criteria except for the stability test of the analyte during chromatography. The instability of the analyte is indicated that not all spots form a straight diagonal line. The specificity of the method was carried out by comparing the fingerprint patterns of the leaves of the anting-anting with ekor kucing (Acalypha hibsida Farm.) and teh-tehan plants (Acalypha siamensis). The fingerprint profile showed a yellow stain (Rf = 0.39) on the leaves of the anting-anting, which did not appear in the fingerprint profiles of the two comparison samples. Keywords: anting-anting, fingerprint analysis, thin layer chromatography, method validation Anting-anting (Acalypha indica L.) merupakan tanaman yang telah dimanfaatkan masyarakat sebagai bahan baku obat herbal. Anting-anting mengandung banyak senyawa kimia sehingga sulit menjamin keamanan dan pengendalian mutu dari tanaman tersebut. Penelitian ini dilakukan untuk validasi metode dengan mengetahui kestabilan, spesifitas, presisi, dan ketegaran profil kromatografi senyawa alkaloid pada analisis KLT ekstrak anting-anting. Ekstraksi dilakukan menggunakan pelarut etil asetat selama 20 menit dengan frekuensi 42 kHz. Eluen yang digunakan adalah sikloheksana : toluena : dietilamin (75:15:10) dengan reagen Dragendorff. Validasi metode dapat diterima sesuai kriteria kecuali uji stabilitas analit selama kromatografi. Ketidakstabilan analit ditunjukkan dengan seluruh noda yang dihasilkan tidak membentuk garis diagonal yang lurus. Spesifitas pada metode dilakukan dengan membandingkan pola sidik jari daun anting-anting dengan daun ekor kucing (Acalypha hibsida Farm) dan daun teh-tehan (Acalypha siamensis). Profil sidik jari menunjukkan bahwa terdapat noda berwarna kuning kehijauan (Rf = 0,39) pada daun anting-anting yang tidak muncul pada profil sidik jari kedua sampel pembanding tersebut. Kata kunci: anting-anting, analisis sidik jari, kromatografi lapis tipis, validasi metode

Antioxidant and Cytotoxicity Activities of the Fermentation Extract of the Endophytic Fungi from the Marine Biota of Colt Coral

Indonesia has the largest and most biodiverse coral reef in the world. Colt coral has not been studied and explored especially endophytic fungi associated with the coral. Endophytic fungi are highly potential for the production of antioxidant and anticancer compounds. This research aimed to study the antioxidant and cytotoxic activities of fermentation extract from endophytic fungi from colt coral. Filtrate and mycelium extracts were obtained from static and shake fermentations of isolate SKF 15. Antioxidant and cytotoxic assays were conducted by free radical scavenger 1,1-diphenyl-2-picrylhydrazyl (DPPH) and AlamarBlue methods, respectively. The result showed that FD extract provided the highest antioxidant activity with inhibition of 49.36% at 200 ppm of DPPH. Variation of fermentation time (3-21 days) demonstrated the highest activity with inhibition of 66.97% for antioxidant assay (7 days) and 81.13% for cytotoxic assay (3 days). FTIR analysis presented the existence of hydroxyl groups O-H (3452.58 cm-1), C=C groups (1668.43 cm-1); C-O hydroxyl group (1230.58 cm -1), and C-H sp3 groups (2941.44 cm-1). Based on LC-MS analysis, FD extract has a mass of m/z 305.63, [M+H]+, predicted as dihydroquercetin (C15H24O7). Keywords: Antioxidant assay, cytotoxic assay, endophytic fungi, colt coral, DPPH method, AlamarBlue method

Ekstraksi Minyak Atsiri dari Bunga Mawar (Rosa hybrda L.) dengan Metode Solvent Free Microwave Extraction

To date, essential oils still play an important role in various aspects of human life. Flowers are essential oil-producing plants that still need to be further explored, of which rose petals (Rosa hybrda L.) are an option for types of flowers that have the potential to produce economical essential oils. In this study, solvent-free microwave extraction (SFME) was used as an essential oil extraction method, which is considered safe because it does not use heat energy and chemical solvents which can be considered to trigger a decrease in the quality of the oil extract. The optimum microwave power in this study is 560 Watt with a yield of 0.0124%. The difference in the value of the feed intake ratio to the volume of the distiller (F/D) influences yield, where the F/D value of 0.15 g/mL gives the highest yield value of 0.0145%. The result of the Gas Chromatography Mass Spectrometry (GCMS) analysis shows rose flower essential oil extract provided a profile of 12 compounds, of which three dominant compounds are β-phenylethyl acetate, 2-isopropyl-5-methyl-9-methylene-bicyclo-1-decene, and nonadecane. Keywords: Extraction, rose flower petals, solvent-free microwave extraction (SFME), essential oils Hingga saat ini, minyak atsiri masih memegang peranan penting untuk berbagai aspek kehidupan manusia. Bunga-bungaan merupakan tanaman penghasil minyak atsiri yang masih perlu dieksplorasi lebih lanjut, yang mana mahkota bunga mawar (Rosa hybrda L.) adalah satu opsi jenis bunga yang berpotensi sebagai penghasil minyak atsiri bernilai ekonomis. Pada penelitian ini digunakan solvent-free microwave extraction (SFME) sebagai metode ekstraksi minyak atsiri yang dinilai aman karena tidak menggunakan energi panas dan bahan pelarut kimia yang dapat dianggap memicu penurunan kualitas ekstrak minyak. Daya microwave optimum pada penelitian ini adalah 560 Watt dengan perolehan yield sebesar 0,0124%. Perbedaan nilai rasio feed masuk terhadap volume distiler (F/D) memberikan pengaruh terhadap hasil rendemen, yang mana nilai F/D 0,15 g/mL memberikan nilai rendemen tertinggi sebesar 0,0145%. Hasil analisis Gas Chromatography Mass Spectrometry (GCMS) menunjukkan bahwa ekstrak minyak atsiri bunga mawar memberikan profil 12 senyawa dengan tiga senyawa dominan yaitu β-phenylethyl acetate, 2-isopropyl-5-methyl-9-methylene-bicyclo-1-decene, dan nonadecane. Kata kunci: Ekstraksi, mahkota bunga mawar, solvent-free microwave extraction

Analisis Kualitas Air Berdasarkan Parameter Fisika di Wilayah Kota Bengkulu

Water is a source of basic human needs. Clean water quality will affect environmental health and all activities in it. This study aimed to measure the quality of the water around beaches, rivers and swamps near settlements in Bengkulu City. The research location consisted of nine points with a radius of 0-2 km from the beach. Sampling was carried out using the stratified disproportional random sampling method with measured parameters including temperature, total dissolved solids (TDS) and water turbidity. The method used in the data analysis is the STORET scoring system. The samples were tested using TDS and turbidity meter based on the Arduino Uno ATMega 328. Results of temperature measurement showed relatively stable values in the range of 29-30°C; TDS values were 53-565 mg/L and water turbidity levels ranged from 90.8 to 1938.1 NTU. Based on the results of the analysis using the STORET scoring system, the water quality status in the study area was included in the medium polluted category (score -15) of 3 test parameters (temperature, TDS and water turbidity). Keywords: Water quality, physical parameter, STORET method, Bengkulu City Air merupakan sumber kebutuhan dasar manusia. Kualitas air yang bersih akan mempengaruhi kesehatan lingkungan dan seluruh aktivitas didalamnya. Tujuan penelitian ini adalah untuk mengukur kualitas air yang ada di sekitar pantai, sungai dan rawa dekat pemukiman di Kota Bengkulu. Lokasi penelitian terdiri dari 9 titik dengan radius 0-2 km dari pinggir pantai. Pengambilan sampel dilakukan dengan menggunakan metode stratified disproportional random sampling dengan parameter yang diukur diantaranya suhu, total dissolved solids (TDS) dan kekeruhan air. Metode yang digunakan dalam analisis data yaitu sistem penilaian STORET. Pengujian sampel dilakukan dengan TDS meter dan turbidity meter berbasis Arduino Uno ATMega 328. Hasil pengukuran suhu menunjukkan nilai yang relatif stabil dengan kisaran 29-30°C; nilai TDS antara 53-565 mg/L dan tingkat kekeruhan air pada rentang 90,8-1938,1 NTU. Berdasarkan hasil analisis menggunakan sistem penilaian STORET, status mutu air di wilayah penelitian termasuk pada kategori cemar sedang (skor -15) berdasarkan 3 parameter uji (suhu, TDS dan kekeruhan air). Kata kunci: Kualitas air, parameter fisika, metode STORET, Kota Bengkulu

Free-Radical Scavenging Activity (FRSA) of Secondary Metabolite Extracted from Indonesian Eucheuma spinosum

IIndonesia is the biggest country in the production of red seaweed of Eucheuma spinosum. The red seaweed has bioactive compounds that have a potential activity such as phenolic compounds as well as carrageenan and pigments. This paper reported phytochemical analysis of E. spinosum harvested by a local farmer in Sumenep Island, East Java and free-radical scavenging activity (FRSA) derived from 2,2’-diphenyl-1-picrylhdrazyl (DPPH) for several organic solvents. For extraction, dried powder is added with 5.0 mL of various solvents following by ultra-sonication assisted extraction for 30 minutes. The extract was separated by centrifugation for phytochemical analysis and radical scavenging evaluation. The prospecting of dichloromethane, ethyl acetate, and n-hexane extracts indicated the potency for radical scavengers. Alkaloids, terpenoids, and saponins were secondary metabolites that indicated the presence in the extracts. The best IC50 value was presented by ethyl acetate extracts (384,86 ppm) with 38.78% for 50 ppm, while IC50 values of n-hexane, methanolic, dicloromethane extracts were 410.12, 677.76 and 685.08 ppm, respectively. Keywords: Eucheuma spinosum, phytochemical analysis, radical scavenging activity

Sintesis dan Karakterisasi Poly (Anthranilic Acid-Co-Formaldehyde) untuk Adsorpsi Ion Pb(II)

Besides having a positive impact, rapid industrial development also gives a negative impact in the form of industrial waste causing environmental pollution. Lead is one of the heavy metal ions that become a primary indicator of pollution according to the United States Environmental Protection Agency (US EPA). The determination of lead directly in environmental samples is often difficult because of the very low concentration of metal ions and the matrix interferences. Therefore, preconcentration techniques that can simplify the matrix are required. Ionic exchange resins, functionalized chelating resins, and ion imprinted polymers are mostly used to preconcentrate the trace elements. Poly (anthranilic acid-co-formaldehyde) is polymer synthesized by mixing anthranilic acid, formaldehyde, and HCl. The poly (anthranilic acid-co-formaldehyde) was characterized by FTIR and SEM analysis. Characterization results indicate that polymerization reaction has been formed indicated by the vibration of the CH2 bridge. Poly (anthranilic acid-co-formaldehyde) has a relatively smooth surface with pores. The batch method was applied. The maximum adsorption for Pb(II) ions was 16.37 mg/g at pH 5 with a contact time of 10 minutes. Keywords: poly (anthranilic acid-co-formaldehyde), adsorption, lead Selain memberikan dampak positif, perkembangan industri yang pesat juga dapat memberikan dampak negatif berupa limbah industri penyebab pencemaran lingkungan. Timbal merupakan salah satu ion logam berat yang menjadi indikator primer pencemaran menurut United States Environmental Protection Agency (US EPA). Penentuan konsentrasi timbal secara langsung dalam sampel lingkungan seringkali sulit dilakukan karena terdapat pada konsentrasi renik dengan matriks yang rumit. Oleh karena itu, teknik prakonsentrasi yang dapat menyederhanakan matriks sangat diperlukan. Resin penukar ion, resin pengkhelat, dan ion imprinted polymers banyak digunakan untuk prakonsentrasi unsur renik. Poly (anthranilic acid-co-formaldehyde) merupakan polimer yang disintesis dengan cara mencampurkan asam anthranilat, formaldehida, dan HCl. Karakterisasi poly (anthranilic acid-co-formaldehyde) telah dilakukan menggunakan FTIR dan SEM. Hasil karakterisasi mengindikasikan bahwa reaksi polimerisasi telah terbentuk yang ditunjukkan dengan adanya vibrasi CH2 bridge. Poly (anthranilic acid-co-formaldehyde) memiliki morfologi permukaan yang relatif halus dan berpori. Metode yang digunakan untuk mempelajari kemampuan adsorpsi adalah metode batch. Kapasitas adsorpsi poly (anthranilic acid-co-formaldehyde) terhadap ion Pb(II) adalah 16,37 mg/g pada pH 5 dengan waktu kontak 10 menit. Kata kunci: poly (anthranilic acid-co-formaldehyde), adsorpsi, timbal

Aktivitas Antibakteri Membran Nanokomposit Kitosan/Nanopartikel Perak

The aim of this study was to make and test the antibacterial activity of chitosan/silver nanoparticles nanocomposite membranes. Nanocomposite membranes were synthesized by chitosan with pluronic using acetic acid as a solvent. Silver nanoparticles were synthesized using the green synthesis method and the makasar fruit (Brucea javanica L. Merr) peel extract as a bioreductor. The silver nanoparticles were composited with a chitosan/pluronic mixture and printed on a glass plate. Nanocomposite membranes were characterized using the FTIR spectrophotometer and the scanning electron microscope (SEM). Nanocomposite membrane were tested for antibacterial activity against Escherechia coli. The UV-Vis spectra showed the formation of silver nanoparticles which were indicated by the absorption at 454 nm and the absorbance value of 0.405. Characterization using FTIR showed no new functional groups formed in the composites of chitosan and pluronic. SEM results showed the difference between the chitosan membrane and the nanocomposite membrane. The surface of nanocomposite membrane showed uneven compared to the chitosan membrane. Nanocomposite membranes have antibacterial activity to inhibit E. coli growth. Keywords: nanocomposite, chitosan/silver nanoparticles, antibacterial Penelitian ini bertujuan untuk membuat dan menguji aktivitas antibakteri membran nanokomposit kitosan/nanopartikel perak. Membran nanokomposit dibuat dengan mensintesis kitosan dengan pluronik menggunakan pelarut asam asetat. Nanopartikel perak disintesis menggunakan metode green synthesis dengan ekstrak kulit buah makasar (Brucea javanica L. Merr) sebagai bioreduktor. Nanopartikel perak dikompositkan dengan campuran kitosan/pluronik dan dicetak di atas plat kaca. Membran nanokomposit dikarakterisasi menggunakan spektrofotometer FTIR dan scanning electron microscope (SEM). Membran nanokomposit dilakukan uji aktivitas antibakteri terhadap Escherechia coli. Spektra UV-Vis menunjukkan terbentuknya nanopartikel perak yang ditandai adanya serapan pada panjang gelombang 454 nm dan absorbansi 0,405. Karakterisasi dengan FTIR menunjukkan tidak adanya gugus fungsi baru yang terbentuk pada komposit dari kitosan dan pluronik. Hasil SEM menunjukkan adanya perbedaan antara membran kitosan dengan membran nanokomposit. Permukaan membran nanokomposit terlihat tidak rata dibandingkan membran kitosan. Membran nanokomposit memiliki aktivitas bakteri sehingga dapat mengambat pertumbuhan bakteri E. coli. Kata kunci: nanokomposit, kitosan/nanopartikel perak, antibakteri

Analisis Kadar Arsen (As) pada Sayur Kubis Hijau (Brassica oleracea L.) Pasca Erupsi Gunung Sinabung

ount Sinabung has had an impact on the lives of surrounding farmers after the eruption. One of the negative impacts is the exposure of plants and animals around them to dangerous chemical compounds, especially heavy metals. This work aimed to analyze the levels of arsenic (As) in green cabbage (Brassica oleracea L.) which was exposed after two months of the eruption. The sampling method was done using a simple random sampling technique at five points. The digestion process was carried out using hydrochloric acid and nitric acid. Arsenic analysis was performed using the atomic absorption spectroscopy (AAS) at 193.7 nm with vapor hydride generation accessories. Concentration of arsenic exposed to green cabbage at five sampling points was 0.4102, 0.4936, 0.4501, 0.6425, and 0.6534 mg/Kg. The results obtained were lower than the maximum limit of arsenic contamination in vegetables, namely 1.0 mg/Kg based on SNI No. 7387:2009.Keywords: arsenic, Brassica oleracea L, AAS, SNI, Mount SinabungGunung Sinabung memiliki pengaruh kepada kehidupan petani di sekitarnya pasca erupsi. Salah satu dampak negatifnya adalah terpaparnya tumbuhan dan hewan di sekitar terhadap senyawa kimia yang berbahaya, khususnya logam berat. Penelitian ini bertujuan untuk menganalisis kadar arsen (As) yang terdapat pada sayur kubis hijau (Brassica oleracea L.) yang terpapar setelah dua bulan erupsi. Pengambilan sampel dilakukan dengan menggunakan teknik simple random sampling di lima titik. Proses destruksi dilakukan dengan menggunakan asam klorida dan asam nitrat. Analisis arsen dilakukan dengan menggunakan atomic absorption spectroscopy (AAS) pada panjang gelombang 193,7 nm yang dilengkapi vapour hydride generation accessories. Kadar arsen yang terpapar pada sayur kubis hijau pada lima titik pengambilan sampel berturut turut sebesar 0,4102; 0,4936; 0,4501; 0,6425, dan 0,6534 mg/Kg. Kadar arsen yang diperoleh lebih rendah dari batas maksimum cemaran arsen dalam sayuran yakni 1,0 mg/Kg berdasarkan SNI No. 7387:2009.Kata kunci: arsen, Brassica oleracea L., AAS, SNI, Gunung Sinabung

Penentuan Aktivitas Antioksidan Senyawa Kuersetin dan Ekstrak Lengkuas Menggunakan HPLC dan UV-Vis

The radical scavenging activity of 1,1-diphenyl-2-picrylhidrazyl (DPPH) is generally carried out using a spectrophotometric method. In this study, the value of the antioxidant activity was compared to the HPLC method. Samples used were pure quercetin and extracts of red galangal (Alpinia purpurata) and white galangal (Alpinia galanga). Analysis of antioxidant activity using a UV/Vis spectrophotometer was carried out at a wavelength of 515 nm. Analysis by HPLC method was carried out using an inverse phase with a UV/Vis detector at 515 nm. The results showed that the radical scavenging activity (IC50) of the pure quercetin produced was nearly the same value for the spectrophotometric method (16.24 ppm) dan the HPLC method (15.24 ppm). Even though, the antioxidant activity of pure quercetin was different from the extract. The red galangal extract gave IC50 of 488.43±1.13 ppm (spectrophotometric method) and IC50 of 68.12±10.19 ppm (HPLC method). The radical scavenging activity (IC50) of white galangal extract using the spectrophotometric method and HPLC method was 462.47±2.98 and 62.17±3.87 ppm, respectively. The allegation of other molecular interference in the radical reduction of the extract resulted in a conclusion that the HPLC is better than the spectrophotometric method for determining antoxidant activity of extract sample. Keywords: Antioxidant, Alpinia purpurata, Alpinia galanga, DPPH Aktivitas peredaman radikal 1,1-diphenyl-2-picrylhidrazyl (DPPH) pada umumnya dilakukan menggunakan metode spektrofotometer. Dalam penelitian ini, nilai aktivitas antioksidan tersebut telah dibandingkan dengan metode HPLC. Sampel ujinya adalah senyawa kursetin murni dan ekstrak lengkuas merah (Alpinia purpurata) dan lengkuas putih (Alpinia galanga). Analisis aktivitas antioksidan dengan spektrofotometer UV/Vis dilakukan pada panjang gelombang 515 nm. Analisis dengan metode HPLC dilakukan menggunakan fasa inverse dengan detektor UV/Vis pada 515 nm. Hasil penelitian menunjukkan bahwa aktivitas peredaman radikal senyawa murni kuersetin menghasilkan nilai yang hampir sama untuk kedua metode yaitu IC50 sebesar 17,05 ppm untuk metode spektrofotometer dan IC50 sebesar 15,74 ppm untuk metode HPLC. Akan tetapi, nilai aktivitas antioksidan kuersetin jauh berbeda untuk ekstrak. Ekstrak lengkuas merah memberikan IC50 sebesar 488,43±1,13 ppm (metode spektrofotometer) dan 68,12±10,19 ppm (metode HPLC). Aktivitas peredaman radikal ekstrak lengkuas putih dengan metode spektrofotometer dan HPLC dengan IC50 sebesar 462,89±5,38 dan 62,17±3,87 ppm, berturut-turut. Dugaan adanya interferensi molekul lain dalam analisis peredaman radikal terhadap ekstrak ini menghasilkan suatu kesimpulan bahwa metode HPLC lebih baik digunakan dalam analisis antioksidan dibandingkan metode spektrofotometer untuk sampel berupa ekstrak. Kata kunci: Antioksidan, Alpinia purpurata, Alpinia galanga, DPPH