scholarly journals OPTIMIZATION OF TIME REACTION AND HYDROXIDE ION CONCENTRATION ON FLAVONOID SYNTHESIS FROM BENZALDEHYDE AND ITS DERIVATIVES

2010 ◽  
Vol 5 (2) ◽  
pp. 163-168 ◽  
Author(s):  
Sri Handayani ◽  
Sunarto, Sunarto, ◽  
Susila Kristianingrum
Keyword(s):  
Reaction Time ◽  
Optimum Concentration ◽  
Ion Concentration ◽  
Optimum Time ◽  
Hydroxide Ion ◽  
Synthesis Time ◽  
Flavonoid Synthesis ◽  
Hydroxyl Ion ◽  
Optimum Reaction ◽  
Time Of Reaction

The aim of this research is to determine the optimum time of reaction and concentration of hydroxide ion on chalcone, 4-methoxychalcone and 3,4-dimethoxychalcone synthesis. Chalcone and its derivatives were synthesized by dissolving KOH in ethanol followed by dropwise addition of acetophenone and benzaldehyde. Then, the mixture was stirred for several hours. Three benzaldehydes has been used, i.e : benzaldehyde, p-anysaldehyde and veratraldehyde. The time of reaction was varied for, 12, 18, 24, 30 and 36 hours. Furthermore, on the optimum reaction time for each benzaldehyde the hydroxyl ion concentration was varied from 5,7,9,11 and 13%(w/v). The results of this research suggested that the optimum time of chalchone synthesis was 12 hours, while, 4-methoxychalcone and 3,4-dimethoxychalcone were 30 hours. The optimum concentration of hydroxide ion of chalcone synthesis was 13% and for 4-methoxychalcone and 3,4-dimethoxychalcone were 11%. Keywords: Chalcone synthesis, time of reaction, hydroxide ion concentration.

scholarly journals PENURUNAN KADAR AMONIAK DAN FOSFAT LIMBAH CAIR TAHU SECARA FOTO KATALITIK MENGGUNAKAN TiO2 DAN H2O2

2018 ◽  
Vol 8 (2) ◽  
pp. 87
Author(s):  
Taufiqur Rohman ◽  
Azidi Irwan ◽  
Zakiyatir Rahmi
Keyword(s):  
Waste Water ◽  
Reaction Time ◽  
Ultra Violet ◽  
Optimum Concentration ◽  
Photocatalytic Reaction ◽  
Phosphate Content ◽  
Optimum Time ◽  
Ammonia Content ◽  
Uv Lamp ◽  
Uv Rays

Decreasing of Amoniac and Phosphate Content of Tofu Wastewater by photocatalytic Using TiO2 And H2O2          The research reduction of ammonia and phosphate content of photocatalytic tofu wastewater by using TiO2 and H2O2 had been done. The aim of this research is to find out the optimum concentration of TiO2 and H2O2, reaction time to decrease ammonia and phosphate in tofu wastewater after treatment with photocatalytic reaction. The photocatalytic reaction was used to degradation of ammonia and phosphate with the radiation by UV lamp, photocatalyst and oxidant. The results are shown that of ammonia content in artificial waste was decreased, variation in the concentration of TiO2, H2O2, and time obtained the optimum concentration of 50 mg/L, 140 mg/L and the optimum time for 60 minutes with a percentage 72,18%, 86,00%, and 83.11%. The decrease of phosphate content, that found of variation in the concentration of TiO2, H2O2, and time obtained the optimum concentration of 100 mg/L, 160 mg/L and the optimum time for 300 minutes with a percentage 79,34%, 77,59% and 78,12% respectively. The photocatalytic treatment of the tofu waste water carried out the addition with aeration. Measurement level of ammonia in tofu wastewater without aeration and with aeration a percentage of decreased are 56.5% and 66.14%. Measurement of phosphate without aeration and with aeration a percentage of decrease are 47.03% and 53.30%. Concluded, ammonia and phosphate content in tofu wastewater can be decreased by photocatalytic with UV rays. Keywords: tofu wastewater, photocatalytic, ammonia, phosphate, TiO2, H2O2  ABSTRAK          Penelitian tentang penurunan kadar amoniak dan fosfat limbah cair tahu secara foto katalitik menggunakan TiO2 dan H2O2 telah dilakukan. Penelitian ini bertujuan untuk mendapatkan konsentrasi TiO2 dan H2O2 optimum, dan waktu reaksi terbaik untuk penurunan amoniak dan fosfat limbah cair tahu setelah pengolahan dengan reaksi foto katalitik. Reaksi foto katalitik digunakan untuk mendegradasi amoniak dan fosfat dengan bantuan sinar ultra violet, fotokatalis dan oksidan. Hasil penelitian menunjukkan bahwa penurunan kadar amoniak pada limbah buatan dengan variasi konsentrasi TiO2 dan H2O2 didapatkan konsentrasi optimum sebesar 50 mg/L dan 140 mg/L dengan persentase penurunan sebesar 72,18% dan 86,00%. Penurunan kadar fosfat dengan variasi konsentrasi TiO2 dan H2O2 didapatkan konsentrasi optimum sebesar 100 mg/L dan 160 mg/L dengan persentase penurunan sebesar 79,34% dan 77,59%. Pada variasi waktu didapatkan waktu terbaik selama 60 menit pada amoniak dan 300 menit pada fosfat dengan persentase penurunan sebesar 83,11% dan 78,12%. Pada perlakuan foto katalitik terhadap limbah cair tahu dilakukan aerasi. Pengukuran kadar amoniak limbah cair tahu tanpa aerasi dan aerasi didapatkan persentase penurunannya sebesar 56,50% dan 66,14%. Pengukuran kadar fosfat limbah cair tahu tanpa aerasi dan aerasi didapatkan persentase penurunannya sebesar 47,03% dan 53,30%. Disimpulkan bahwa kadar amoniak dan fosfat limbah cair tahu terjadi penurunan secara foto katalitik dengan bantuan sinar UV. Kata Kunci: limbah cair tahu, foto katalitik, amoniak, fosfat, TiO2, H2O2

scholarly journals STUDY OF COLLOIDAL CHITIN HYDROLYSIS TO PRODUCE THE N ACETYL GLUCOSAMINE FROM SHRIMP SHELL WASTE USING HYDROCHLORIC ACID AND NITRIC ACID

2015 ◽  
Vol 2 (1) ◽  
pp. 77
Author(s):  
Sri Wahyuni
Keyword(s):  
Nitric Acid ◽  
Reaction Time ◽  
Hydrochloric Acid ◽  
Acid Hydrolysis ◽  
Optimum Concentration ◽  
Colloidal Chitin ◽  
Optimum Temperature ◽  
Chitin Hydrolysis ◽  
Optimum Reaction

Shrimp processing industries produces shrimp waste by 30-75% is wasted without being processed causing environmental pollution. The purpose of this study examines efforts to produce monomers of chitin hydrolysis of colloidal chitin compound derived from shrimp shells are chemically (hydrochloric acid and nitric acid) to produce N acetyl glucosamine bioactive compounds that have health benefits. The method used in this study is the optimization of chemical hydrolysis conditions using a solution of HCl and HNO3. On determining the optimum time to sample variation colloidal chitin 0,5%, 1% and 2%, the sample is heated with time variation 1,3,6, 9,12, and 24 hours at a temperature of 60 oC and the concentration of acid was 4 M. In the determination of the optimum temperature, each sample was heated at a temperature variation of 40, 60, and 80 oC at the optimum time (9 hours ) and acid concentration of 4 M. In the determination of the optimum concentration of acid, each sample was heated at a temperature and the optimum reaction time. Production results showed the highest compound N acetyl glucosamine as 623.3 ppm, using hydrochloric acid hydrolysis reaches optimum temperature 40° C, the optimum reaction time 9 hours, the optimum concentration of 4 M hydrochloric acid, the concentration of 2% colloidal chitin. Production of N acetyl glucosamine supreme as 625.83 ppm, using nitric acid hydrolysis reaches optimum temperature 60° C, the optimum reaction time 9 hours, the optimum concentration of 4M nitric acid, and the concentration of 1% colloidal chitin. Therefore we can conclude the results of 1% colloidal chitin hydrolysis using nitric acid more efficiently produce N acetyl glucosamine than hydrochloric acid, due to the temperature, reaction time, and acid concentration are not the same ability to hydrolyze colloidal chitin. Differences in the results of hydrolysis reached 11,59 ppm. Keywords : Chitin, N acetyl glucosamine, acid hydrolysis, optimum reaction 

Residual phase lignin in haft cooking related to the conditions in the cook

1997 ◽  
Vol 12 (4) ◽  
pp. 225-229
Author(s):  
Cart-in A-S. Gustavsson ◽  
Chritofer T. Lindgren ◽  
Mikael E. Lindström
Keyword(s):  
Hydrogen Sulfide ◽  
Ionic Strength ◽  
Sodium Ion ◽  
Ion Concentration ◽  
Constant Composition ◽  
Hydroxide Ion ◽  
Sulfide Ion ◽  
Residual Phase ◽  
Kraft Cooking ◽  
Very High

Abstract The amount of lignin reacting according to the slow residual phase, i.e. the residual phase lignin, is in many perspectives an interesting issue. The purpose of the present investigation was to develop a mathematical model to show how the amount of residual phase lignin in the kraft cooking of spruce chips (Picm ahies) depends on the conditions in the earlier phases of the cook. The variables studied were hydroxide ion concentration, hydrogen sulfide ion concentration and ionic strength. The liquor-to-wood ratio during pulping was very high to maintain approximately constant chemical concentrations throughout each experiment (so called "constant composition" cooks). An increase in hydroxide ion concentration andtor hydrogen sulfide ion concentration leads to a decrease in the amount of residual phase lignin, while an increase in ionic strength, i.e. sodium ion concentration, leads to an increase. A signiticant result is that the hydrogen sulfide ion concentration has a pronounced influence on the amount of residual phase lignin during a cook at a low hydroxide ion concentration. The amount of residual phase lignin expressed as % lignin on wood, L,, can be described by the following equation developed for "constant composition" cooks (when cooking with a constant sodium ion concentration of 2 mol/L): LT=0,55-0.32*[HO-](-1,3)*ln[HS-] This equation is valid for a concentration of HO- in the range from 0.17 to 1.4, and a hydrogen sulfide ion concentration from 0.07 to 0.6 mol/L.

Study on the Synthesis of Isoamyl Acetate Catalyzed by Strong Acidic Cation Exchange Resin

2011 ◽  
Vol 396-398 ◽  
pp. 2411-2415 ◽  
Author(s):  
Ping Lan ◽  
Li Hong Lan ◽  
Tao Xie ◽  
An Ping Liao
Keyword(s):  
Acetic Acid ◽  
Reaction Time ◽  
Cation Exchanger ◽  
Cation Exchange Resin ◽  
Isoamyl Acetate ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Reaction Conditions ◽  
Optimum Reaction

Isoamyl acetate was synthesized from isoamylol and glacial acetic acid with strong acidic cation exchanger as catalyst. The effects of reaction conditions such as acid-alcohol ratio, reaction time, catalyst dosage to esterification reaction have been investigated and the optimum reaction conditions can be concluded as: the molar ratio of acetic acid to isoamylol 0.8:1, reaction time 2h, 25 % of catalyst (quality of acetic acid as benchmark). The conversion rate can reach up to 75.46%. The catalytic ability didn’t reduce significantly after reusing 10 times and the results showed that the catalyst exhibited preferably catalytic activity and reusability.

scholarly journals Optimization of Synthesis of Seleno-Sargassum fusiforme(Harv.) Setch. Polysaccharide by Response Surface Methodology, Its Characterization, and Antioxidant Activity

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Yu-Bin Ji ◽  
Fang Dong ◽  
Miao Yu ◽  
Long Qin ◽  
Dan Liu
Keyword(s):  
Antioxidant Activity ◽  
Response Surface Methodology ◽  
Reaction Time ◽  
Response Surface ◽  
Reaction Temperature ◽  
Sargassum Fusiforme ◽  
Synthesis Conditions ◽  
Optimum Reaction ◽  
Series Of Experiments

The response surface methodology was employed to optimize the synthesis conditions of seleno-Sargassum fusiforme(Harv.) Setch. polysaccharide. Three independent variables (reaction time, reaction temperature, and ratio of Na2SeO3to SFPSI) were tested. Furthermore, the characterization and antioxidant activity of Se-SFPSIin vivowere investigated. The result showed that the actual experimental Se content of Se-SFPSI was 3.352 mg/g at the optimum reaction conditions of reaction time 8 h, reaction temperature 71°C, and ratio of Na2SeO3to SFPSIB 1.0 g/g. A series of experiments showed that the characterization of Se-SFPSIB was significantly different from that of SFPSIB. Additionally, antioxidant activity assay indicated that the Se-SFPSIB could increase catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activity of mice bearing tumor S180in blood, heart, and liver while decreasing malondialdehyde (MDA) levels. It can be concluded that selenylation is a feasible approach to obtain seleno-polysaccharide which was utilized as highly biological medicine or functional food.

Zeolite Syntheses from Superalkaline Reaction Mixtures

1992 ◽  
Vol 57 (4) ◽  
pp. 788-793 ◽  
Author(s):  
Falk Fischer ◽  
Marianne Hadan ◽  
Günter Fiedrich
Keyword(s):  
Ir Spectroscopy ◽  
Crystalline Phase ◽  
Ion Concentration ◽  
Single Crystalline ◽  
Hydroxyl Ion ◽  
Type Zeolite

The synthesis of faujasite-type zeolite from superalkaline reaction mixtures are described. The contribution shows the influence of component K2O added in the system Na2O-Al2O3-SiO2-H2O with H2O/(K2O + Na2O) = 13-15. The reaction course was investigated in the range K2O/(K2O + Na2O) from about 0.07 to 0.5. Under used conditions it is quite possible to isolate faujasite-type zeolite as a single crystalline phase. By means of IR spectroscopy, low SiO2/Al2O3 ratios from 2.0 to 2.1 in the faujasite framework have been indicated. The low SiO2/Al2O3 ratios are interpreted by a higher stability of the Si-O-Al- than the Si-O-Si- bond with increasing hydroxyl ion concentration.

scholarly journals Activation of Soluble Polysaccharides with 1-Cyano-4-Dimethylaminopyridine Tetrafluoroborate (CDAP) for Use in Protein–Polysaccharide Conjugate Vaccines and Immunological Reagents. III Optimization of CDAP Activation

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 777
Author(s):  
Andrew Lees ◽  
Jackson F. Barr ◽  
Samson Gebretnsae
Keyword(s):  
Reaction Time ◽  
Low Temperature ◽  
Scale Up ◽  
Optimal Time ◽  
Conjugate Vaccines ◽  
Maximal Activation ◽  
Optimum Reaction ◽  
Rapid Reaction ◽  
The Stability ◽  
High Level

CDAP (1-cyano-4-dimethylaminopyridine tetrafluoroborate) is employed in the synthesis of conjugate vaccines as a cyanylating reagent. In the published method, which used pH 9 activation at 20 °C (Vaccine, 14:190, 1996), the rapid reaction made the process difficult to control. Here, we describe optimizing CDAP activation using dextran as a model polysaccharide. CDAP stability and reactivity were determined as a function of time, pH and temperature. While the rate of dextran activation was slower at lower pH and temperature, it was balanced by the increased stability of CDAP, which left more reagent available for reaction. Whereas maximal activation took less than 2.5 min at pH 9 and 20 °C, it took 10–15 min at 0 °C. At pH 7 and 0 °C, the optimal time increased to >3 h to achieve a high level of activation. Many buffers interfered with CDAP activation, but DMAP could be used to preadjust the pH of polysaccharide solutions so that the pH only needed to be maintained. We found that the stability of the activated dextran was relatively independent of pH over the range of pH 1–9, with the level of activation decreased by 40–60% over 2 h. The use of low temperature and a less basic pH, with an optimum reaction time, requires less CDAP, improving activation levels while making the process more reliable and easier to scale up.

scholarly journals Biocatalytic Pickering Emulsions Stabilized by Lipase-Immobilized Carbon Nanotubes for Biodiesel Production

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 587 ◽  
Author(s):  
Lihui Wang ◽  
Xinlong Liu ◽  
Yanjun Jiang ◽  
Liya Zhou ◽  
Li Ma ◽  
...  
Keyword(s):  
Reaction Time ◽  
Seed Oil ◽  
High Efficiency ◽  
Polynomial Equation ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Multiwall Carbon Nanotube ◽  
Pickering Emulsions ◽  
Optimum Reaction ◽  
Immobilized Candida Antarctica Lipase

Biodiesel is a promising renewable energy source that can replace fossil fuel, but its production is limited by a lack of high-efficiency catalysts for mass production and popularization. In this study, we developed a biocatalytic Pickering emulsion using multiwall carbon nanotube-immobilized Candida antarctica lipase B (CALB@PE) to produce biodiesel, with J. curcas L. seed oil and methanol as substrates. The morphology of CALB@PE was characterized in detail. A central composite design of the response surface methodology (CCD-RSM) was used to study the effects of the parameters on biodiesel yield, namely the amount of J. curcas L. seed oil (1.5 g), molar ratio of methanol to oil (1:1–7:1), CALB@PE dosage (20–140 mg), temperature (30–50 °C), and reaction time (0–24 h). The experimental responses were fitted with a quadratic polynomial equation, and the optimum reaction conditions were the methanol/oil molar ratio of 4.64:1, CALB@PE dosage of 106.87 mg, and temperature of 34.9 °C, with a reaction time of 11.06 h. A yield of 95.2%, which was basically consistent with the predicted value of 95.53%, was obtained. CALB@PE could be reused up to 10 times without a substantial loss of activity. CALB@PE exhibited better reusability than that of Novozym 435 in the process of biodiesel production.

Microwave-Assisted Synthesis of Cadmium Sulfide Nanoparticles: Effect of Hydroxide Ion Concentration

2013 ◽  
Vol 1617 ◽  
pp. 151-156 ◽  
Author(s):  
Israel López ◽  
Idalia Gómez
Keyword(s):  
Cadmium Sulfide ◽  
Aqueous Dispersion ◽  
Threshold Concentration ◽  
Ion Concentration ◽  
Microwave Assisted Synthesis ◽  
Cubic Phase ◽  
Hydroxide Ion ◽  
Microwave Assisted ◽  
Cadmium Sulfide Nanoparticles ◽  
Vis Spectroscopy

ABSTRACTCadmium sulfide nanoparticles were synthesized by a microwave-assisted route in aqueous dispersion. The cadmium sulfide nanoparticles showed an average diameter around 5 nm and a cubic phase corresponding to hawleyite. The aqueous dispersions of the nanoparticles were characterized by UV-Vis spectroscopy, luminescence analysis, transmission electron microscopy and X-ray diffraction. The addition of sodium hydroxide solutions at different concentrations causes a red-shift in the wavelength of the first excitonic absorption peak of the cadmium sulfide nanoparticles, indicating a reduction of the band gap energy. Besides, the intensity of the luminescence of the nanoparticle dispersions was increased. However, there is a threshold concentration of the hydroxide ion above which the precipitation of the cadmium sulfide nanoparticles occurs.

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