• Bulletin of the Korean Chemical Society
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• v.22 no.5
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• pp.441-442
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• 2001

• Natural Product Sciences
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• v.29 no.1
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• pp.24-30
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• 2023

Adenanthera pavonina L. is an important medicinal plant for Indonesian traditional medicine ("Jamu"). The present study is to determine the phenolic content and evaluate the antioxidant activity of ethyl acetate and ethanolic extracts of leaves and bark of A. pavonina. The total phenolic content was determined using the Folin-Ciocalteu reagent methods, and the antioxidant activity was performed by phosphomolybdate assay, through EC₅₀ values. The highest phenolic content (81.379 mg GAE/g) was found in the hydro-ethanolic extract of the leaves and (80.630 mg GAE/g) in the bark. The antioxidant activity of the two samples was 42.270 ㎍/mL (leaves) and 45.261 ㎍/mL (bark). Plants have the potential as drugs with good antioxidant potential and phenolic compound content. Further scientific studies of this plant are supported to evaluate the antioxidant activity using other methods to validate these preliminary experiments properly.

• Journal of Environmental Science International
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• v.10 no.1
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• pp.13-19
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• 2001

An on-line digestion system based on the flow injection analysis technique was presented for the determination of total phosphorus. The system converts condensed and organic phosphoruses into orthophosphate that can be analyzed spectrophotometically. The reaction between orthophosphate and ammonium molybdate in a strong acid medium forms the yellow complex of phosphomolybdate which is next reduced to a molybdic blue complex by stannous chloride. The quantitation of orthophosphate is based on the absorbance of the molybdic blue. To determine total phosphorus, the digestion system was installed between the sample injector and the reaction coil with the added lines of digestion solution(potassium persulfate+sulfuric acid) and the $H_2O$ carrier. The system has shown that the digestion efficiencies were greater than 95% for the typical condensed and organic phosphoruses. When tripolyphosphate standards were used, the calibration data showed that the linear dynamic range extended to a concentration of 1.5ppm with the detection limit of 25ppb total phosphorus. The typical relative standard deviation was less than 2%. The proposed system was successfully applied to lake water, wastewater, and streamwater. The analytical variables such as digestion efficiency, analysis time, and reproducibility were evaluated and compared with the manual digestion method.