Kajian Kadar Akrilamida dalam Kopi Arabika dengan Variasi Suhu Penyangraian

Acrylamide levels in Arabica coffee at various roasting temperatures have been determined. Coffee beans are roasted at 160°C, 180°C, and 210°C for 8 minutes. Analysis was carried out using High-Performance Liquid Chromatography (HPLC) with C-18 reversed-phase, mobile phase using methanol and 0.1% phosphoric acid solution (5:95), flow rate 1 mL/min, UV-Vis detector 198 nm wavelength. Acrylamide levels in Arabica coffee are 160°C of 14.665 ppm, 180°C of 15.973 ppm, and 210°C of 18.501 ppm. Based on the results of the acrylamide content in Arabica coffee, the higher the roasting temperature, the greater the acrylamide content. ANOVA test regarding the normality test sig value of 0.637, 0.463, and 0.637 normally distributed. Based on the homogeneity test, it was found that the variation between groups was the same or homogeneous. The results of the ANOVA test stated that there were differences in the acrylamide levels of Arabica coffee in the roasting temperature difference group and the results of the post hoc Bonferroni test found that the average differences in the roasting temperature of Arabica coffee were significantly different 160°C-180°C and 160°C-210°C.

Microwave Assisted Extraction of Berberine and Preparation of Berberine Hydrochloride from Berberis Aristata Variety of Nepal, and Quantification using RP-HPLC and HPTLC Methods

Berberis aristata a Himalayan woody spiny shrub with yellow flowers and red berries commonly called as Daruharidra in Sanskrit and locally in Nepal is called as Chutro or Chitra. The root and stem are the two parts widely used in traditional medicines of India and China. Berberine is the key active ingredient present in stem and root parts. Berberine hydrochloride is the derivative of berberine. The present study aimed to study the microwave assisted extraction of berberine and its conversion into berberine hydrochloride and quantifying by RP-HPLC and HPTLC methods.In the present paper we have mentioned microwave assisted extraction of berberine and preparation of berberine hydrochloride in detail. Berberine extracted from roots of Berberis aristata using microwave assisted extraction in 80% ethanol to obtain 20% pure berberine crude by HPTLC densitometry at 350 nm absorption. The crude berberine was further purified to berberine hydrochloride by adding 10% Hcl in aqueous solution of berberine and allowed to crystallize at 5 0C over 24 hours. The crystals were further purified and recrystallized in ethanol and subjected to RP-HPLC. Reverse phase HPLC was carried out on Shimadzu UV detector at wave length of 265 nm using Acetonitrile-0.1% phosphoric acid solution (50:50) (add 0.1g sodium dodecyl sulfonate per 100ml) as the mobile phase; Phenomenex RP-column (250 mm × 4.6 mm, 5 μm), With flow rate 1.0 mL/minute, 5 µL injection volume, column temperature 25 0C for run time of 35 minutes, and retention time of berberine hydrochloride was 12.008 minutes with purity of 82% and recovery of 90% yield obtained.

Preparation of 1060, 2024 and 7075 Aluminum Alloy Anodic Oxide Films

On aluminum alloys of grades 1060, 2024 and 7075, regular and highly uniform oxide films were formed by anodic oxidation. Anodizing was carried out at a constant pressure in a phosphoric acid solution of various concentrations. Using scanning electron microscopy (SEM) and X-ray diffraction (XRD), the optimal characteristics of the method of anodic oxidation for forming uniform oxide films on aluminum alloys were determined: anodic oxidation time, temperature, voltage and the concentration of H3PO4. It was found that, in the process of anodizing, the films have gone through four stages: a non-porosity stage, a mixed stage, an ordered porosity stage and a disordered porosity stage.

Simultaneous Determination of Emtricitabine and Tenofovir disoproxil fumarate in Pharmaceutical Dosage by Reverse Phase High Performance Liquid Chromatography

A simple, rapid and accurate high performance liquid chromatography method is described for simultaneous determination of emtricitabine and tenofovir disoproxil fumarate from active pharmaceutical ingredients. The separation of drug was achieved on Hypersil BDS C18 (150 x 4.6 mm i.d.) with 5 µ particle size column showed most favorable chromatographic pattern over the other columns. The mobile phase consisted of a mixture of buffer and methanol (85:15 % v/v). The buffer was mixtures of 0.1 % (v/v) ortho-phosphoric acid solution adjusted the pH 3.5 with tri-ethyl amine. The detection was carried out at wavelength 260 nm. The mixture of buffer of pH 3.5 and methanol (85:15% v/v) was used as a diluent. The method was validated for system suitability, linearity, accuracy, precision, robustness, stability of sample solution. The method has been successfully used to analyze emtricitabine and tenofovir disoproxil fumarate from active pharmaceutical ingredients.

PREPARATION OF FEED-GRADE MONOCALCIUM PHOSPHATE BY CRYSTALLIZATION IN AQUEOUS MEDIUM: CALCULATION AND EXPERIMENTS

In this paper, we present the results of calculation, and experiments for the preparation of feed-grade monocalcium phosphate by crystallization method in phosphoric acid solution. Some parameters influence to the production such as the reaction and crystallization temperature, the ratio of recycle mother liquor to reactant mixture have been investigated. The results show that the crystallization method in the preparation of monocalcium phosphate will give product with higher quality, less impurities that will be suitable for animal feed additives.

Purification of recovered phosphoric acid by extracting aluminium with di-2-ethylhexyl phosphoric acid

The extraction of aluminium from dilute phosphoric acid with di-2-ethylhexyl phosphoric acid (DEHPA) was optimized using response surface methodology. The optimization was based on the experimental three-level central composite face-centred design (CCF) and was conducted on real-life samples. The three variables included were pH, extractant concentration and aqueous to organic phase ratio (AO). Under the optimized conditions (pH 2.5, 0.6 M DEHPA and AO ratio 1:2), extraction efficiency of 99% for aluminium in four extraction stages is achieved. The purified phosphoric acid solution can then be utilized by the fertilizing industry. Stripping tests for organic phase loaded with aluminium were conducted with sulphuric acid. Extremely high stripping efficiency was obtained with 0.9 M sulphuric acid resulting in the recovery rate of 88% in one stage. After stripping, the aluminium sulphate solution can be reused as a precipitation agent for phosphorus in the wastewater treatment process.

Dual-frequency ultrasonic cleaning with diluted phosphoric acid solution for removing oxide scale of uncoated steel sheets in hot stamping

Dual-frequency ultrasonic cleaning with a diluted phosphoric acid solution was developed to remove oxide scales on surfaces of hot-stamped parts from uncoated steel sheets, and conventional shot blasting processes are omitted. The removal of the oxide scale by ultrasonic cleaning is accelerated by the phosphoric acid solution and the dual frequency. The removing time for the phosphoric acid solution was shorter than that for a hydrochloric acid solution, and rust appearing for leaving after cleaning was prevented by generating an iron phosphate layer. In dual-frequency ultrasonic cleaning with the diluted phosphoric acid solution, the oxide scale was dissolved, and then the oxide scales were exfoliated from the thin scale and high-pressure portions. The removing time decreased with decreasing pH and oxide scale thickness and with increasing solution temperature. The surface roughness and distortion of an ultrasonic-cleaned hot-stamped part were smaller than those for shot blasting, and the weldability and paintability were similar. The oxide scale of a hot-stamped part having a nonuniform distribution of oxide scale thickness was successfully removed by dual-frequency ultrasonic cleaning with the diluted phosphoric acid solution.

Extraction of Rare Earth Metals by Solid-Phase Extractants from Phosphoric Acid Solution

Nowadays, solving the problem of rational, integrated use of the mined raw materials, the transition to waste-free technologies for its processing is a crucial task. The sulfuric acid technology used for the processing of apatite concentrates on a large industrial scale does not provide the associated extraction of accompanying valuable components—rare earth metals (REM). During apatite concentrate processing, rare-earth metals are affected by the technology-related dispersion, being distributed between the insoluble leaching residue and phosphoric acid solution sent to the production of fertilizers. The necessity of a cost-effective method development for the extraction of rare earth metals is quite obvious already in connection with the indicated significance of the problem. Phosphoric acid solutions that simulate the composition of industrial phosphoric acid solutions of the following composition 4.5 mol/L H3PO4, 0.19 mol/L H2SO4 and 0.10–0.12% REM were selected as the object of research. The extraction of rare earth metals was carried out using polymers containing a fixed layer of an extractant—di-2-ethylhexylphosphoric acid (D2EHPA). Fixed layer was obtained by impregnation-saturation (solvent-impregnated resin (SIR)) or by the introduction of an extractant at the stage of polymer matrix synthesis (extractant-resin extraction (ERE)). The work determined the thermodynamic and technological characteristics of the solid-phase extraction of rare earth elements from phosphoric acid solutions with polymers impregnated with D2EHPA and containing a rigidly fixed extractant in a styrene-divinylbenzene resin matrix. The possibility of effective multiple use of polymeric resins containing D2EHPA, regenerated with a solution of 1 mol/L sodium citrate, was revealed.