SINTESIS DAN STUDI STABILITAS NANOPARTIKEL PERAK TERTUDUNG ASAM SALISILAT

Silver nanoparticles capped with salicylic acid have been synthesized by reduction of silver nitrate with salicylic acid without additional capping agent. In the formation of silver nanoparticles, the solution of silver nitrate was first mixed with the pH 11 salicylic acid solutions at a mole ratio of 1:40. The mixture was heated for 45 minutes in a boiling water bath. The formation of silver nanoparticles was indicated by the appearance of yellow color and monitored using UV-Vis spectrophotometer. The maximum peak of resulted silver nanoparticles appeared in the range of 410-420 nm with the average size of particles was 66±28 nm. Stability test over a period of 16 weeks showed that silver nanoparticles capped with salicylic acid were stable. The results of stability test show that salicylic acid simultaneously act as reducing as well as capping agent in the formation of silver nanoparticles.

BIOADSORPSI Fe(II) OLEH KULIT BUAH JERUK Citrus nobilis Lour. var microcarpa TERMODIFIKASI Ca(OH)2

Pontianak peel fruit waste contains pectin, cellulose, and hemicellulose which can be used as heavy metal adsorbents by modifying using Ca(OH)2. The purpose of this study was to determine the physicochemical characteristics of calcium-modified Pontianak Citrus adsorbents (JeP-Oca), determine the maximum capacity of Fe(II) adsorption by JeP-OCa, and JeP-OCa adsorption kinetics. The characteristics of the adsorbent were analyzed using the Fourier Transformation Infra Red (FTIR) showing the functional groups of –OH and -COOH, Electron Scanning (SEM) Microscopy showing the surface structure of the canal and many irregular niches. The adsorption isotherm method with the BET model showed a large difference in porous surface area, namely 104.872 m2/g for JeP, 242.649 m2/g for JeP-ONa and 3759.745 m2/g for JeP-OCa. Optimization of the influence of pH, adsorbent mass, adsorbate concentration, and time using the column method. Adsorption isotherm followed the Freundlich isotherm model with maximum adsorption capacity value of 22.7272 mg/g. Fulfill the pseudo-order 2 reaction kinetics with a rate constant value of 4.097 L/mg. Min. The adsorption application using groundwater resulted in absorption efficiency of 82.99%.

PENENTUAN STRUKTUR SENYAWA ANTIOKSIDAN LIMONOID DARI BIJI JERUK SAMBAL (Citrus microcarpa Bunge) KALIMANTAN BARAT

Limonoid has been isolated from orange seeds of Citrus microcarpa Bunge using extraction and partitioning methods. It is a yellowish-white crystal with a melting point of 276-277 oC. Based on the phytochemical analysis and FTIR spectroscopy, 1H NMR and compared with the literature, the compound is limonin which is a triterpenoid. The purpose of this study was to determine the structure and evaluate antioxidant activity of the limonin. The antioxidant activity by DPPH obtained IC50 value of limonin was 199.18 ppm. Whereas, the test antioxidant activity by FRAP method using a comparative solution of ascorbic acid showed that there was an increasingly blue color change, which meant that antioxidant activity was stronger with activity value of 11.88 mgAAE /g sample.

ADSORPTION OF Pb(II) BY POLYANILINE/SILICA GEL COMPOSITE: KINETICS AND ISOTHERM STUDIES

Research on the study of kinetics and isotherm adsorption of Pb(II) by polyaniline/silica gel (PANI/SiO2) composite from glass waste has successfully been done. The polymerization of silica gel was prepared by sol-gel process. Meanwhile, PANI/SiO2 composite was prepared using sulfuric acid (H2SO4) as its dopants and hydrogen peroxide (H2O2) for oxidation process. Composition of oxide compound in PANI/SiO2 composite was analyzed by X-Ray Fluorosence (XRF) and Gas Sorption Analyzer (GSA). Adsorption of Pb(II) was carried out by contacting PANI/SiO2 with Pb(NO3)2 solution for 20, 40, 60 and 80 minutes, with concentrations of 150, 200, 250, 300, 350 and 400 mg/L. The optimum contact time was reached at 40 minutes. This adsorption followed pseudo-second order model with R2= 0.996. The first optimum adsorption capacity was reached in the concentration of 250 mg/L. Isotherm adsorption followed Langmuir models with R2= 0.954 (monolayer capacity= 51.02 mg/g).

EKSTRAKSI DAUN PELAWAN (Tristaniopsis merguensis)SEBAGAI ANTIOKSIDAN MENGGUNAKAN MICROWAVE ASSISTED EXTRACTION (MAE)

Indonesia is a country that produces a wealth of abundant biodiversity, one of which is a plant that is often cultivated the tree of Pelawan (Tristaniopsis merguensis). Pelawan trees are widely spread in Indonesia one of them found in the forests of the Bangka Belitung island. Therefore, this study aims to identify the secondary metabolites and testing antioxidants in leaf of pelawan extract by comparing methods of Microwave Assisted Extraction (MAE) with maceration method. The resistant leaf used in this study was obtained from Sempan, Bangka Belitung. The observation result shows that the use of MAE method can extract with faster time compared with maceration method. So the MAE method is more effective than the maceration method. The using of MAE method for 30 minutes obtained the highest yield percentage of 41.3% in ethanol solvent which is more effective than acetone solvent. Extraction by using 48 hour maceration yields is 28.985%. While the extraction with 30 minute maceration is 13.385%. Testing of antioxidant activity using Microwave Assisted Extraction (MAE) method on acetone solvent has the highest antioxidant activity than ethanol extract that is 9,501 μg/mL. The use of the MAE method is more efficient in extracting the leaves of Pelawan than the maceration method when viewed from the time and antioxidant activity.

GREEN SYNTHESIS NANOPARTIKEL PERAK MENGGUNAKAN EKSTRAK DAUN PUCUK IDAT (Cratoxylum glaucum) SEBAGAI BIOREDUKTOR

An environment friendly technique for green synthesis of silver nanoparticles has been reported. Silver nanoparticle have been synthesized using water extract of leaves of pucuk idat (Cratoxylum glaucum), commonly known as local Bangka plant. The flavonoid and tannin present in the extract act as reducing agent. AgNO3 0,05 M solution was reducing using the extract at room temperature by stirring. Color changing of the solution was detected at 30 minutes reaction time. The color tends to be darker by the increasing of reaction time. Various techniques used to characterize synthesized nanoparticles are UV-Visible spectrophotometer, x-ray diffraction (XRD) and scanning electron microscopy (SEM). UV-Visible spectrophotometer showed absorbance peak in 405 nm, the XRD shows that silver nanoparticles formed are crystalline. The average particle size of Ag nanoparticles estimated from the Scherrer formula is 35,59 nm, while SEM image shows shape of silver nanoparticle is random and some spherical shape.

DETEKSI KEBERADAAN BAKTERI RESISTEN LOGAM MERKURI (Hg) PADA PENAMBANGAN EMAS TANPA IZIN (PETI) DI SIMPI, SEKADAU, KALIMANTAN BARAT

The purpose of this research is to know the existence of mercury metal degradation bacteria in the activity of illegal gold mining (PETI) in Simpi Village, Belitang Hilir sub-district, Sekadau District, West Kalimantan. The samples were taken from one location with three different sampling points. Isolation of bacteria by pour plate method in NA-HgCl medium. Detection of bacteria by paper disc method based on inhibit zone resistant of Mueller-Hinton Agar (MHA) with mercury levels such as 10 mg/L, 20 mg/L and 30 mg/L . The results showed that it was found that one pure isolate (PP) showed the most resistant isolate to the mercury stress of 10 mg/L can be detected

ANTIFUNGAL ACTIVITY OF METHANOL EXTRACT OF BLACK CUMIN SEEDS ON Aspergillus sp.

Aspergillus sp. is a type of pathogenic fungus and can cause pulmonary aspergillosis. This research aims to determine the concentration of methanol extract from black cumin (Nigella sativa) seeds which effective to inhibit the growth of Aspergillus sp. (RMPRB2). This research used poisoned food method with Completely Randomized Design consisting of six treatments with four replications. The results showed that the methanol extract of Nigella sativa seeds could inhibit the growth of fungal isolates from Aspergillus sp. (RMPRB2). The Methanol extract of Nigella sativa with a concentration of 2% and the positive control gave a strong inhibitory activity to the growth of Aspergillus sp. (RMPRB2) with a percentage of 100%. Concentration of 1% is the most effective result because gave a very strong inhibitory activity to the growth of fungal isolates of Aspergillus sp. (RMPRB2).

PHYTOCHEMICAL SCREENING, ANTIOXIDANT, AND CYTOTOXICITY OF Zamioculcas zamiifolia ROOT EXTRACT

Zamioculcas zamiifolia is an ornamental plant that had been used pharmacologycally as a traditional medicine plant. The aims of this research were to investigate the phytochemistry of n-hexane, chloroform and methanol extracts from the roots of Z. zamiifolia and to evaluate their biological activities as antioxidant and cytotoxic. All extracts were screened phytochemically using specific reagents and TLC technique to reveal the major component of each extract. The chloroform was obtained as the highest quantity of extract which gave positive test for steroids and flavonoids. All extracts were tested for their antioxidant activity using DPPH method and for their cytotoxic activity against two types of human cancer cell lines, HepG2 and T47D, and normal African green monkey kidney ephitelial cell lines, Vero. The methanol and chloroform extract exhibited antioxidant activity with AA50 values of 180.0 and 431.5 µg/mL, respectively. Chloroform and methanol extracts showed potencial and moderate cytotoxicity towards T47D cell line with IC50 433.1 and 461.1µg/mL, respectively. None of the extracts was toxic against HepG2 and Vero cell lines.

KINETIKA DEGRADASI SELULOSA ASETAT DARI SABUT PINANG

Cellulose Acetate is a material with wide range in applications. Cellulose acetate may obtain from natural resources, such as areca fiber. Polymers should have uniform molecular weight for the applications and could be modify by ultrasonic waves. Ultrasonic treatment on polymer entangled with polymer degradation. In this research, degradation kinetics of cellulose acetate in acetone had been studied. Analysis was performed by determination of intrinsic viscosity in polymer solution system. Intrinsic viscosity was successfully obtained by fitting data using Huggins equation, indicate molecular interaction in polymer solution should not be neglected. Increasing in sonication time reducing the intrinsic viscosities as well as molecular size in solutions. Degradation rate constant and reaction order were obtained 5,975x10-3(g.mL-1)0,1.min-1 and 1,0616, respectively. Kinetics model was successful to determine the degradation rates of cellulose acetate on acetone by correlation coefficient (R2) at 0,966.