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Retno Yusiasih
Division of Analytical Chemistry and Standard, Research Center for Chemistry, Indonesian Institute of Sciences, Jl. Cisitu-Sangkuriang, Bandung 40135
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GROWTH RESPONSE OF NANNOCHLOROPSIS AT OUTDOOR CULTIVATION IN MEDIUM WITH VARIATION OF NITROGEN CONCENTRATION Astuti, J. Tri; Sriwuryandari, Lies; Yusiasih, Retno; Sembiring, Tarzan
Teknologi Indonesia Vol 33, No 2 (2010)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (16.048 KB) | DOI: 10.14203/jti.v33i2.20

Abstract

Micro-algae are fast-growing unicellular photosynthetic microorganisms that able to fi x CO2 while capturing solar energy. Source and concentration of nitrogen itself affected to the growth character and composition of microalgae. Cultivation with limited of nitrogen resulted great increase in the lipid content. This study was conducted to investigate the infl uence of nitrogen concentration to the growth rate and lipid characteristics of Nannochloropsis sp. In this study, ammonium nitrate (NH4NO3) was added in different concentration, i.e. 0; 30; 70; and 100% based on nitrogen content in f/2 medium, or equivalent to 0; 1.06; 2.47; and 3.53 (10-4 M). All treatment was prepared triplicate, then cultivated at outdoor batch culture systems and aerated continuously with a sterilized of atmospheric air. The algae biomass was harvested at 14th day after inoculated and then analyzed. Data showed that Nannochloropsis sp. could be cultivated in the outdoor batch system, which temperature was in the range of 26.1137.97oC, with average of 33.44oC. Compared to its initial condition, pH culture increased signifi cantly from 6.92 to 8.54. The highest OD680nm (0.500) and dry cell concentration (458mg.L-1) was obtained by using NH4NO3 at 2.47x10-4 M. The lipid content was 63.58% and 46.59% of dry cell weight when using nitrogen 1.06x 10-4M and 2.47x10-4M, respectively. Composition of fatty acid was not signifi cantly affected by the changing of nitrogen concentration. Palmitic acid (C16:0) was the most of fatty acid in Nannochloropsis sp. (44.4753.97%), followed by lauric acid (25.7834.34%), and myrictic acid (19.0721.19%). The using of N-NH4NO3 at 2.47x10-4M gave the highest lipid content of 213.15mg.L-1.
METHOD DEVELOPMENT OF SONICATION TECHNIQUE EXTRACTION FOR DETERMINATION OF CARBOFURAN PESTICIDE IN SPIKE SOIL SAMPLE BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY Yusiasih, Retno; Pitoi, Mariska M; Ariyani, Miranti
Teknologi Indonesia Vol 41, No 1 (2018)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (16.054 KB) | DOI: 10.14203/jti.v41i1.527

Abstract

A method for determination of carbofuran pesticides residue utilizing extraction by sonication has been developed for spike soil sample collected from horticulture farms in Lembang, North Bandung Regency, Indonesia. The simple, reliable, and cost-effective method was performed without any clean up prior injection to HPLC-UV. The method was validated by evaluating its detection limit, linearity, repeatability, recovery, and matrix effect. The detection limit of the method is 0.50 mg/kg. The linearity of the method is very good (r=0.99677) for concentration range of 1.0 to 5.0 mg/kg. The repeatability of the method is acceptable (CV value of 2.56 %). The fortified recoveries are acceptable, ranging from 93.44 to 101.03%. Statistical analysis shows that the matrix effect is insignificant to the method. The application of the method is able to offer a minimization of waste, miniaturization of method, and increased the safety for the operator as required for Green Analytical Chemistry.
Co-Authors astuti, J. Tri Miranti Ariyani Pitoi, Mariska M Sembiring, Tarzan Sriwuryandari, Lies