Ammonium Sulfate Concentration Research Articles

Multi-dimensional Studies on Thermotolerant Phosphate Solubilizing Bacteria Isolated from Rock Phosphate Mines for Bioactivation of Rock Phosphate

We conducted multi-parametric studies on thermotolerant phosphate solubilizing bacteria useful in bioactivation of rock phosphate. Selected two different thermotolerant phosphate solubilizing cultures. Statistical optimization found pH, ammonium sulfate and EDTA concentration to be the significant variables for high phosphate solubilization by Bacillus sp. BISR-HY63. Alkaline phosphatase production by Brevibacillus sp. BISR-HY07 was increased from 1400 unitsL−1 to 3000 unitsL−1. Partial purification of alkaline phosphatase performed by size exclusion and anion-exchange chromatography and the enzyme purified by 76 folds. Organic compost prepared and inoculated with alkaline phosphatase producing bacterium BISR-HY07 for increasing it’s efficacy. Soluble P decreased from 9.5 mgKg−1 to 4.1 mgKg−1 and available P increased from 200 mgKg−1 to 1000 mgKg−1 after incubation of 50 days. When cultures used as bioinoculants, total P content absorbed by the plants inoculated by Brevibacillus sp. BISR-HY07 along with rock phosphate was highest and significantly higher at 9.3 gkg−1. Shoot length of plants treated by rock phosphate and Brevibacillus sp. BISR-HY07 found to be highest and significantly higher at 31.5 cm. Root length, shoot biomass and root biomass of plants treated by rock phosphate and Bacillus sp. BISR-HY63 was highest but not significantly high at 10.3 cm, 0.73 g and 0.34 g respectively.

Design of novel temperature-resistant and salt-tolerant acrylamide-based copolymers by aqueous dispersion polymerization

ABSTRACT Development of polymer-based flooding technology to improve oil recovery efficiency, water dispersion copolymerization of acrylamide, cationic monomer methacryloxyethyltrimethyl ammonium chloride (METAC), and anionic monomer acrylic acid (AA) were carried out in aqueous ammonium sulfate solution with polyvinyl pyrrolidone (PVP) as the stabilizer. The copolymers were characterized by 1H-NMR, FT-IR, TG, and SEM to confirm that they were prepared successfully and exhibited excellent salt-resistant property. Moreover, the effect of the aqueous solution of ammonium sulfate (AS) concentration, stabilizer concentration, and initiator concentration on the viscosity and size were systematically investigated. To further improve the thermal endurance properties of copolymer, hydrophobic monomers with different alkyl chain lengths were added to the above system. The acrylamide-based quadripolymer possessed prominent thermal and salt endurance properties by utilizing the advantages of zwitterionic structure and hydrophobic monomer. With the temperature rising, the viscosity retention could reach 70.2% in the water and 63.8% in the saline. This work had expected to provide a new strategy to design polymers with excellent salinity tolerance and thermal-resistance performances.

A comprehensive mechanistic analysis of silver dissolution with the monoethanolamine-copper-ammonium system and the development of a novel leaching technology

In the present research, the novel system of monoethanolamine-copper-ammonium was electrochemically studied to improve our knowledge of the reaction mechanism of silver dissolution. This paper introduces the effect of varying the concentration of monoethanolamine (MEA), ammonium sulfate, copper sulfate and temperature on the silver leaching kinetics and mechanism. The study has been complemented with thermodynamic analysis, characterization techniques (FESEM-EDS), leaching tests with H2O2 as oxidizing agent and electrochemical techniques such as Tafel, linear voltammetry and open circuit potential. The results demonstrate that it is possible to dissolve silver inhibiting the Cu(OH)2 precipitation in the system by increasing the concentration of MEA up to 1.5 M. The anodic polarization of silver reveals that an increase in the MEA concentration from 0.05 to 1.5 M, promotes the silver oxidation kinetics, maintaining the concentrations of 0.3 and 0.8 M of CuSO4 and (NH4)2SO4, respectively. Furthermore, the Tafel analysis shows that an increase in temperature from 15 to 45 °C minimizes the charge transfer coefficient and increases the silver oxidation kinetics using a leaching solution which avoids the precipitation of copper hydroxide species. The electrochemical results reveal the catalytic role of MEA during the silver dissolution and the possibility to eliminate the use of cupric ions while an energetic condition higher than 0.4 V vs SHE is maintained. In the case of silver sulfide dissolution, the results revealed that the reductive decomposition of silver sulfide is favored at a more cathodic potential than −0.6 V vs SHE with the MEA-Na2SO4-(NH4)2SO4 system, this cathodic pre-treatment facilitates the accelerated dissolution of silver from Ag2S using the same MEA leaching system. Finally, it is possible to dissolve 81 % of metallic silver using a conventional batch reactor with the MEA-Na2SO4-(NH4)2SO4-H2O2 novel system at room temperature.

Characteristics of Bromelain enzyme from Queen variety pineapple crown at different drying temperatures

Pineapple (Ananas comosus (L) Merr) is a plant that contains bromelain enzymes in almost all parts of the plant, such as fruit, leaves, crown, and the stem with different amounts. Bromelain is included in the protease enzyme group that can break down the molecular structure of proteins into amino acids. Pineapple crown is one of the waste products from pineapple processing that has not been used optimally. This study aims to utilise Queen pineapple crown waste and determine the characteristics of Queen pineapple crown bromelain enzymes which consist of protein content, unit activity, and specific activity at different drying temperatures. Queen pineapple crowns were dried using a cabinet dryer at the temperature of 35°C, 40°C, 45°C, and 50°C before the extraction process. The optimum temperature in the Queen pineapple crowns drying process to produce bromelain with a protein content of 4.41 mg/ml, unit activity 1.36 U/ml, and specific activity 0.31 U/ml was 40°C, then purified by adding 20%, 40%, 60%, and 80% ammonium sulfate. The optimum concentration of ammonium sulfate used to produce pure bromelain (0.33 U/mg specific activity) from Queen pineapple crowns was 60%.

Potential and whole-genome sequence-based mechanism of elongated-prismatic magnetite magnetosome formation in Acidithiobacillus ferrooxidans BYM.

A magnetosome-producing bacterium Acidithiobacillus ferrooxidans BYM (At. ferrooxidans BYM) was isolated and magnetically screened. The magnetosome yield from 0.5896 to 13.1291mg/g was achieved under different aeration rates, ferrous sulfate, ammonium sulfate, and gluconic acid concentrations at 30℃. TEM observed 6-9 magnetosomes in size of 20-80nm irregularly dispersed in a cell. STEM-EDXS and HRTEM-FFT implied that the elongated-prismatic magnetite magnetosomes with {110} crystal faces grown along the [111] direction. Whole-genome sequencing and annotation of BYM showed that 3.2Mb chromosome and 47.11kb plasmid coexisted, and 322 genes associated with iron metabolism were discovered. Ten genes shared high similarity with magnetosome genes were predicted, providing sufficient evidence for the magnetosome-producing potential of BYM. Accordingly, we first proposed a hypothetic model of magnetosome formation including vesicle formation, iron uptake and mineralization, and magnetite crystal maturation in At. ferrooxidans. These indicated that At. ferrooxidans BYM would be used as a commercial magnetosome-producing microorganism.

Iron from coal combustion particles dissolves much faster than mineral dust under simulated atmospheric acidic conditions

Abstract. Mineral dust is the largest source of aerosol iron (Fe) to the offshore global ocean, but acidic processing of coal fly ash (CFA) in the atmosphere could be an important source of soluble aerosol Fe. Here, we determined the Fe speciation and dissolution kinetics of CFA from Aberthaw (United Kingdom), Krakow (Poland), and Shandong (China) in solutions which simulate atmospheric acidic processing. In CFA PM10 fractions, 8 %–21.5 % of the total Fe was found to be hematite and goethite (dithionite-extracted Fe), and 2 %–6.5 % was found to be amorphous Fe (ascorbate-extracted Fe), while magnetite (oxalate-extracted Fe) varied from 3 %–22 %. The remaining 50 %–87 % of Fe was associated with other Fe-bearing phases, possibly aluminosilicates. High concentrations of ammonium sulfate ((NH4)2SO4), often found in wet aerosols, increased Fe solubility of CFA up to 7 times at low pH (2–3). The oxalate effect on the Fe dissolution rates at pH 2 varied considerably, depending on the samples, from no impact for Shandong ash to doubled dissolution for Krakow ash. However, this enhancement was suppressed in the presence of high concentrations of (NH4)2SO4. Dissolution of highly reactive (amorphous) Fe was insufficient to explain the high Fe solubility at low pH in CFA, and the modelled dissolution kinetics suggest that other Fe-bearing phases such as magnetite may also dissolve relatively rapidly under acidic conditions. Overall, Fe in CFA dissolved up to 7 times faster than in a Saharan dust precursor sample at pH 2. Based on these laboratory data, we developed a new scheme for the proton- and oxalate-promoted Fe dissolution of CFA, which was implemented into the global atmospheric chemical transport model IMPACT (Integrated Massively Parallel Atmospheric Chemical Transport). The revised model showed a better agreement with observations of Fe solubility in aerosol particles over the Bay of Bengal, due to the initial rapid release of Fe and the suppression of the oxalate-promoted dissolution at low pH. The improved model enabled us to predict sensitivity to a more dynamic range of pH changes, particularly between anthropogenic combustion and biomass burning aerosols.

Pembuatan Konsentrat Protein Ampas Tahu Menggunakan Garam Ammonium Sulfat

Tofu pulp which generally becomes waste can be used as a source of protein concentrate. Protein concentrates from tofu pulp have been obtained at various ratios of tofu pulp: ammonium sulfate and ammonium sulfate salt concentration. The research was conducted to obtain the highest protein yield and content of tofu pulp protein concentrate. This study used a completely randomized design (CRD) with the independent variable being the ratio of tofu pulp filtrate: ammonium sulfate (1:2, 1:3, 1:4, 1:5, 1:6, and 1:7 (v/v)) and concentrations of ammonium sulfate (30, 40, 50, 60, 70, and 80%), while the dependent variables were the yield of protein concentrate and protein content. Production of protein concentrate used the salting-out method with ammonium sulfate salt. The ratio of tofu pulp: ammonium sulfate 70% obtained the best ratio of 1:5 with a yield of 41.6% and protein content of 84.58%. Tofu pulp as industrial waste can be a potential source of protein concentrate because it has a high protein content.

Recovery of Rare-Earth Elements from Brazilian Ion-Adsorption Clay: A Preliminary Study

Ion-adsorption clays (IAC) are alumino-silicate ores, considered an essential source of heavy rare-earth elements (REE). With the increasing discovery and exploitation of IAC deposits, the present work sought to evaluate different methods of solubilization of REE through the use of different concentrations of inorganic acids (H 2 SO 4 , HCl, and HNO 3 ), as well as different concentrations of ammonium sulfate and lactic acid. According to the results, the sulfuric acid solution favored the solubilization of both La 3+ and Sm 3+ elements. The solubilization of REE in the presence of ammonium sulfate showed no significant differences as a function of the leaching time but favored the solubilization of Y 3+ and Tb 3+ . More efficient solubilization of Sm 3+ was observed with the addition of lactic acid at a concentration of 30 g L -1 , leading to 90% (4.5 ppm) of Sm 3+ extraction. The solubilization of La 3+ was favored by the contact time, with higher Sm 3+ extraction yields in 14 days of leaching. DOI: http://dx.doi.org/10.17807/orbital.v14i1.1569

Exploration of the cardinal formulation parameters influencing the encapsulation and physicochemical properties of co-loaded anticancer dual drug nanoliposomes

Rationale-based modulation of physico-chemical properties is critical towards design of optimal liposomal formulations having desired pharmacokinetic and pharmacodynamic profiles. The aim of the study was evaluation of critical formulation factors which may influence the encapsulation efficiency, hydrodynamic diameter, electrokinetic potential, internal morphology and drug release profiles of nanoliposomes. Doxorubicin and Vincristine were actively co-loaded in preformed PEGylated liposomes prepared using ethanolic injection. The variation of independent factors (transmembrane gradient, lipid-molar ratio, drug loading temperature, phosphatidylcholine chain length, sequence of drug addition, drug loading pH, external medium) on dependent variables were evaluated using array of univariate analysis with key determinants further analysed using multivariate studies. Univariate study results showed that concentration of ammonium sulphate, drug loading pH and lipid-molar ratio had significant effect on dependent variables. Nanoliposomes prepared in multivariate studies exhibited high encapsulation efficiency (>95%), particle size (Z-average: 106.55 ± 6.63 nm) and surface charge of −5.55 ± 2.77 mV. The optimized nanoliposomes exhibited characteristic coffee-bean shaped morphology showing doxorubicin nanoprecipitation and electron dense vincristine presence in internal aqueous phase that exhibited controlled in-vitro release of both drugs unaffected by presence of each other. Further, an attempt was made to correlate these results to the chemical structure and physicochemical properties of the drugs.

How Xylenol Orange and Ferrous Ammonium Sulphate Influence the Dosimetric Properties of PVA-GTA Fricke Gel Dosimeters: A Spectrophotometric Study.

The development of Fricke gel (FG) dosimeters based on poly(vinyl alcohol) (PVA) as the gelling agent and glutaraldehyde (GTA) as the cross-linker has enabled significant improvements in the dose response and the stability over time of spatial radiation dose distributions. However, a standard procedure for preparing FG in terms of reagent concentrations is still missing in the literature. This study aims to investigate, by means of spectrophotometric analyses, how the sensitivity to the radiation dose and the range of linearity of the dose–response curve of PVA-GTA-FG dosimeters loaded with xylenol orange sodium salt (XO) are influenced by ferrous ammonium sulphate (FAS) and XO concentrations. Moreover, the effect of different concentrations of such compounds on self-oxidation phenomena in the dosimeters was evaluated. PVA-GTA-FG dosimeters were prepared using XO concentrations in the range 0.04–0.80 mM and FAS in the range 0.05–5.00 mM. The optical absorbance properties and the dose response of FG were investigated in the interval 0.0–42.0 Gy. The results demonstrate that the amount of FAS and XO determines both the sensitivity to the absorbed dose and the interval of linearity of the dose–response curve. The study suggests that the best performances of FG dosimeters for spectrophotometric analyses can be obtained using 1.00–0.40 mM and 0.200–0.166 mM concentrations of FAS and XO, respectively.

Aqueous Two-Phase Extraction, Antioxidant and Renal Protective Effects of Polysaccharides from Spores of Cordyceps cicadae

The aim of this study was to investigate the aqueous two-phase extraction (ATPE), in vitro antioxidant, and in vivo renal protective effects of polysaccharides from spores of Cordyceps cicadae (CCSPs). The optimal ATPE parameters were as follows: an extraction temperature of 61 °C, an ammonium sulfate concentration of 18%, an ethanol concentration of 40%, a liquid-to-material ratio of 33 mL/g, and an extraction time of 60 min. Under these parameters, the CCSPs yield was 6.96 ± 0.11% (n = 3), which was consistent with the predicted yield (6.92%). Among the three purified polysaccharide fractions, CCSP-2 displayed stronger scavenging activities against DPPH radicals and hydroxyl radicals, reducing power and ferrous-ion-chelating ability to a greater extent than CCSP-1 and CCSP-3. CCSP-2 exhibited its protective effect in lipopolysaccharide (LPS)-induced septic acute kidney injury (AKI) mice by significantly alleviating renal edema; reducing 24 h urine protein, blood urea nitrogen (BUN), and serum creatinine (SCr); inhibiting the release of serum proinflammatory cytokines; boosting the activities of antioxidant enzymes; and reducing the levels of oxidative damage products. These results suggest that CCSP-2 exerted its protective effect against LPS-induced septic AKI in mice through anti-inflammatory and antioxidant pathways.

Insolubilization of Tramates versicolor laccase as cross-linked enzyme aggregates for the remediation of trace organic contaminants from municipal wastewater

The novelty of this study deals with the biocatalytic treatment of trace organic contaminants (TrOCs) from municipal wastewater by insolubilized laccase. Laccase from Trametes versicolor was aggregated by three-phase partitioning technique followed by cross-linking with glutaraldehyde to produce insolubilized laccase as cross-linked enzyme aggregates (CLEAs). The optimal conditions for CLEAs preparation include ammonium sulphate concentration of 83% (w/v), crude to t-butanol ratio of 1.00: 1.05 (v/v), pH 5.3, and glutaraldehyde concentration of 20 mM obtained via statistical design. The efficiency of insolubilization of the CLEAs laccase based on the kcat/km ratio was approximately 4.8-fold greater than that of free laccase. The developed CLEAs showed greater resistance to product inhibition mediated by ABTS than the free enzyme and exhibited excellent catalytic activity even after the tenth successive cycle. Further, free laccase and the synthesized CLEAs laccase were utilized to treat five analgesics, two NSAIDS, three antibiotics, two antilipemics, and three pesticides in the municipal wastewater. Under the batch process with operating conditions of pH 7.0 and 20 °C, 1000 U/L of CLEAs, laccase removed 11 TrOCs in the range of about 20–99%. However, the inactivated CLEAs only adsorbed 2–25% of TrOCs. It was observed that acetaminophen, mefenamic acid, trimethoprim, and metolachlor depicted almost complete removal with CLEAs laccase. The performance of CLEAs laccase in a perfusion basket reactor was tested for the removal of TrOCs from municipal wastewater.

Ultrasound-Assisted Intensification of β-Glucosidase Enzyme Activity in Free and Immobilized Forms

The focus of the current work was to enhance the productivity and activity of enzymes based on immobilization and application of ultrasound. β-Glucosidase was immobilized using a cross-linking method that was a carrier-free approach. Parameters such as the ammonium sulfate concentration (60–90%), glutaraldehyde concentration (0.5–1.5%), and use of bovine serum albumin (BSA) were optimized during the preparation of cross-linked enzyme aggregates (CLEAs). The optimum temperature (50 °C) and pH (5) were observed to be the same for both the soluble and immobilized enzymes in CLEAs. Use of 1% glutaraldehyde concentration gave a recovery of 30%, but after adding BSA (0.3 mM) the recovery enhanced to 57%. The effect of ultrasonic treatment on enzyme activity was analyzed using an ultrasonic bath with maximum activity observed at a 30% duty cycle, a 50 W power, and a treatment time of 20 min with an actual value of 9.7 U/mL, which was higher as compared to that of the untreated enzyme (8.86 U/mL). The enzyme immobilized after pretreatment with ultrasound allowed an activity recovery of 82% that was significantly higher compared to that of the untreated immobilized enzyme. The immobilized enzyme prepared with a pretreated enzyme exhibited higher reusability and thermal stability as compared to the enzyme immobilized with the untreated enzyme. Overall, an effective method for immobilization of enzymes along with the use of ultrasound for intensification was demonstrated.

Influence of different PEG/salt aqueous two-phase system on the extraction of 2,3-butanediol

The production of 2,3-butanediol (2,3-BDO), a dialcohol of great interest for the food, chemical, and pharmaceutical industry, through the fermentation of biomass, is a sustainable process strategic position for countries with abundant biomass generated by the agribusiness. However, the downstream process of 2,3-BDO is onerous due to the complexity of fermentation broth and the physical-chemical characteristics of the 2,3-BDO. This study investigated the feasibility of 2,3-BDO extraction from model aqueous solutions using aqueous two-phase systems (ATPS). A central composite rotational design (CCRD) was employed to evaluate different ATPS compositions and the influences on the 2,3-BDO recovery and partition coefficient. The polyethylene glycol (PEG) and different concentrations of sodium citrate, ammonium sulfate, and potassium phosphate were investigated. The concentration of salt and PEG in the ATPS was identified as the most significant factors influencing the recovery and partition coefficient of 2,3-BDO. The recovery of 2,3-BDO reached 94.5% and was obtained when the system was composed of 36.22% (w/w) of PEG 4000 and 4.47% (w/w) of potassium phosphate. The results indicate that ATPS based on PEG-salt has a high potential for industrial application, using mild conditions and a simple process for recovering and purifying the 2,3-BDO produced from microbiological synthesis.

Developing an understanding of sophorolipid synthesis through application of a central composite design model.

SummaryA key barrier to market penetration for sophorolipid biosurfactants is the ability to improve productivity and utilize alternative feedstocks to reduce the cost of production. To do this, a suitable screening tool is required that is able to model the interactions between media components and alter conditions to maximize productivity. In the following work, a central composite design is applied to analyse the effects of altering glucose, rapeseed oil, corn steep liquor and ammonium sulphate concentrations on sophorolipid production with Starmerella bombicola ATCC 222144 after 168 h. Sophorolipid production was analysed using standard least squares regression and the findings related to the growth (OD600) and broth conditions (glucose, glycerol and oil concentration). An optimum media composition was found that was capable of producing 39.5 g l–1 sophorolipid. Nitrogen and rapeseed oil sources were found to be significant, linked to their role in growth and substrate supply respectively. Glucose did not demonstrate a significant effect on production despite its importance to biosynthesis and its depletion in the broth within 96 h, instead being replaced by glycerol (via triglyceride breakdown) as the hydrophilic carbon source at the point of glucose depletion. A large dataset was obtained, and a regression model with applications towards substrate screening and process optimisation developed.

Lipid Production by Yarrowia lipolytica B9 Using Crude Glycerol as Carbon Source

The present study was carried out to optimize some culture conditions to increase lipid production from Yarrowia lipolytica B9 in crude glycerol-based medium. The experiments displayed that too high concentrations of ammonium sulfate, KH2PO4, and MgSO4 increased cell growth but inhibited lipid synthesis. In contrast, more synthesis of lipids was determined to be achived at high concentrations of NaCl. The optimum concentrations of glycerol, ammonium sulfate, KH2PO4, MgSO4, and NaCl for lipid synthesis were determined as 50, 3, 1.5, 1 and 5 g/L, respectively. The optimal incubation time for lipid synthesis was found to be 6 days. Lipid concentration of 2.69 g/L and lipid content of 60.1%, were reached under optimal culture conditions.

Three phase purification of milk clotting protease from Wrightia tinctoria fruit and studies on its casein subunit specificity

Crude aqueous extract of Wrightia tinctoria fruit was subjected to three phase partitioning (TPP) with three different ammonium sulphate concentrations (40, 60, 80%) and their effect on concentrating milk clotting proteases were examined with 1:1 ratio of crude extract to t-Butanol. Proteases that concentrated in the interphase (IP) fraction of 60 and 80% salt concentration exhibited high milk clotting activity. TPP contributed to reduction in Caseinolytic Activity (CA) and enhancement of Milk Clotting Index (MCI) in these IP fractions compared to the crude enzyme. Casein (whole and kappa) hydrolytic pattern was analyzed by tricine SDS PAGE. Electrophoretic pattern of hydrolysate after 1 hr incubation revealed hydrolysis of κ-CN by CE, IP 60 and IP 80 fractions. Appearance of two low molecular weight bands approximately around 15 kDa indicated the specific affinity and controlled hydrolytic behavior by the proteases. Study provides evidence towards the utility of TPP in concentrating these milk clotting proteases and in improving their MCI. Keywords : Milk clotting • Wrightia tinctoria • Proteases• cheese

Functionalization of Multiwall Carbon Nano-Tube Supported Zinc Oxide Solid Acid Catalyst Using Sulfonate Compound for Transesterification of Schleichera Oleosa L Oil

Biodiesel is an alternative energy obtained through the trasesterification of vegetable oil in the presence of a catalyst. The catalyst plays a very important role in the success of the transesterification process. One way to increase the activity of the catalyst is through chemical modification called functionalization, which generally using SO3 group as a sulfonating agent is known as the sulfonation process. However, the disadvantage of this process is that it uses strong acids which are corrosive, require high temperatures and are not environmentally friendly. This study aims to increase the activity of zinc oxide catalyst supported by multi-wall carbon nano tube (Z/MWCNTs) sulfonated using (NH4)2SO4 as sulfonating agent. The synthesis route includes co-precipitation, sulfonation and precipitation time. The effect of concentration of ammonium sulfate, co-precipitation time, and sulfonating time on yield of biodiesels of kesambi (Schleichera oleosa L) oil (OSOBD) was investigated. The result showed that the activity functionalized Z/MWCNTS catalyst (Z/s-MWCCNTs) could enhance significantly. The results of the catalyst activity test on transesterification of OSO into biodiesel showed that Z/s-MWCNTs gave a high yield of 91% for the functionalized catalyst using ammonium sulfate with a concentration of 35%, co-precipitation time 12 hours and sulfonation time 4 hours. The functionalization of MWCNTS with the sulfonation process using ammonium sulfate has the potential to increase catalyst activity and can increase the efficiency of the transesterification process for non-edible oils, especially kesambi oil.

Process for synergistic extraction of Hf(IV) over Zr(IV) from thiocyanic acid solution with TOPO and N1923

A novel process for the separation of Hf(IV) over Zr(IV) from thiocyanic acid solution using TOPO and N1923 as the extractant has been developed. It was observed that the mixture of TOPO and N1923 exhibited a synergistic effect on selective extracting the minor element of Hf(IV). Several crucial parameters influencing the separation process have been investigated. The extraction efficiency for Hf(IV) was found to be 86.3% under optimum conditions: TOPO+N1923 total concentration of 16 vol%, TOPO/N1923 ratio of 6/10, HSCN concentration of 2.0 M, ammonium sulfate concentration of 0.5 M and extraction O/A phase ratio of 2/1. Meanwhile, the separation factor for Hf(IV) over Zr(IV) could reach up to 21. Furthermore, the reverse extraction properties of the loaded organic phase were studied systematically. The results suggested that the co-extracted Zr(IV) could be scrubbed by 1.0 M H2SO4 with a separation factor of 24.13. Hf(IV) was then stripped from the loaded organic phase using 2.0 M NH4HCO3. The attractive characteristics of the newly designed process were the use of low thiocyanic acid solution, achieving higher extractability of Hf(IV) over Zr(IV), the recyclable process flow and the potential to prepare high pure Hf and Zr.

THE EVALUATION OF ACTIVITY AND STABILITY OF ISOLATED BROMELAIN FROM PINEAPPLE CORES (ANANAS COMOSUS [L.] MERR) AND IN VITRO PENETRATION TEST OF NANOEMULSION TOPICAL BASE

Objective: Oral administration of bromelain as an anti-inflammation therapy still faces several challenges, such as the risk of contact with the gastric fluid and its low absorption rate. Therefore, bromelain isolated from the pineapple core will be formulated as a topical base in a nanoemulsion to increase its stability, activity, and ability to penetrate the skin. Methods: Bromelain was isolated from pineapple core using ammonium sulfate precipitation and dialysis, and then the isolated fraction was loaded into topical nanoemulsion for subsequent evaluation of its characteristics, stability, enzymatic activity, and for in vitro study of penetration using Franz diffusion cell. Results: The highest specific activity of bromelain fractions found in ammonium sulfate concentration is around 20–50%. After being dialyzed, the bromelain fraction showed an increase in specific activity 2.78-fold as compared to crude extract. The characteristics of bromelain nanoemulsion showed a globule size of 21.37±1.8 nm with a polydispersity index (pdI) 0.323±0.049, oil in water (o/w) type, and the type of rheology was plastic flow. The nanoemulsion stability base was observed, and there was no phase separation after centrifugation. Bromelain in nanoemulsion base showed a proteolytic activity of 5.00 U/ml with a protein content of 154.28 mg/l. In vitro penetration studies using Franz diffusion cell for 8 h showed isolated bromelain in nanoemulsion base has a total cumulative number value of 1386.94 μg/cm2 with penetrated velocity/flux (J) of 45.93 μg/cm2 h. Conclusion: The results showed promise for bromelain loaded into nanoemulsion as a vehicle for topically administered therapeutic enzymes.