scholarly journals ADSORPTION OF AFLATOXIN B1 IN CORN ON NATURAL ZEOLITE AND BENTONITE

2012 ◽  
Vol 12 (3) ◽  
pp. 279-286 ◽  
Author(s):  
Nuryono Nuryono ◽  
Ali Agus ◽  
Sri Wedhastri ◽  
Y.M.S. Maryudhani ◽  
Deni Pranowo ◽  
...  
Keyword(s):  
Particle Size ◽  
Natural Zeolite ◽  
High Performance ◽  
Aqueous Suspension ◽  
Hplc Method ◽  
Elisa Method ◽  
Batch System ◽  
Before And After ◽  
Standard Solution ◽  
The Difference

A study on adsorption of AFB1 in corn (kernel and grained) on natural zeolite and bentonite has been investigated. The first work was adsorption in a batch system of standard AFB1 solution on adsorbents. Some factors such as contact time, concentration of AFB1 and particle size of adsorbent were evaluated. The amount of AFB1 adsorbed was calculated based on the difference of AFB1 concentration before and after adsorption determined by high performance liquid chromatography (HPLC) method. Adsorption of AFB1 in corn sample was emphasized by mixing aqueous suspension of sample with adsorbent. Concentration of AFB1 in suspension was analyzed by enzyme-linked immuno-sorbent assay (ELISA) method. Result shows that adsorption of AFB1 on adsorbents of natural zeolite and bentonite is very fast. Within 15 min 99% of AFB1 (200 ng/mL) has been adsorbed by 25 mg of bentonite and 96% by zeolite. The particle size higher than 200 mesh did not give significant effect on the AFB1 adsorption capability. Effectiveness of zeolite in adsorbing AFB1 is lower than that of bentonite. Capability in reducing AFB1 contamination in corn samples (kernel and meal) for both adsorbents is lower than that in standard solution.

Effect of particle size and delignification on the rate of digestion of hemicellulose and cellulose by cellulase in mature pangola grass stems

1983 ◽  
Vol 34 (3) ◽  
pp. 241 ◽  
Author(s):  
CW Ford
Keyword(s):  
Particle Size ◽  
Cell Walls ◽  
Trichoderma Viride ◽  
Structural Features ◽  
Cell Wall Polysaccharides ◽  
Particle Size Reduction ◽  
Digitaria Decumbens ◽  
Hemicellulose Degradation ◽  
Before And After ◽  
The Difference

Stem cell walls of pangola grass (Digitaria decumbens) were ground to two particle sizes (c. 1 and 0.1 mm diameter), and incubated with cellulase (ex. Trichoderma viride) for varying times before and after delignification. Total cell walls finely ground (0.1 mm) with a Spex Shatterbox mill were initially degraded more rapidly (to 24 h) than delignified 1 mm particles. Thereafter the delignified material was solubilized to a greater extent. Subsequent specific determinations of cell wall polysaccharides indicated that delignification increased the rate of hemicellulose degradation to a greater extent than did particle size reduction, whereas the opposite was found for cellulose. The difference between delignified and Spex-ground residues, in terms of the amount of polysaccharide digested, was much greater for cellulose than hemicellulose. It is concluded that structural features play a more important role in limiting cellulase degradation of cellulose than does association with lignin, the reverse being so for hemicellulose.

scholarly journals ANALYITCAL METHOD DEVELOPMENT AND VALIDATION OF A REVERSED-PHASE HIGHPERFORMANCE LIQUID CHROMATOGRAPHY FOR THE DETERMINATION OF MODAFINIL IN BULK AND PHARMACEUTICAL DOSAGE FORMS

2016 ◽  
Vol 9 (5) ◽  
pp. 177
Author(s):  
Bijithra Cholaraja ◽  
Shanmugasundaram P ◽  
Ragan G ◽  
Sankar Ask ◽  
Sumithra M
Keyword(s):  
Particle Size ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Reversed Phase ◽  
Dosage Forms ◽  
Hplc Method ◽  
Rp Hplc ◽  
Development And Validation

ABSTRACTObjective: To development and validation of a reversed-phase high-performance liquid chromatography (RP-HPLC) for the determination of modafinilin bulk and pharmaceutical dosage forms.Methods: A simple, precise, rapid, and accurate RP-HPLC method was developed for the estimation of modafinil in bulk and pharmaceutical dosageforms. Xterra RP 18 (250 mm × 4.6 mm, 5 µ particle size) with a mobile phase consisting of methanol:water 70:30 V/V was used. The flow rate1.0 ml/min and the effluents were monitored at 260 nm. The retention time and recovery time was 12 minutes. The detector response was linear inthe concentration of 10-50 µg/ml. The respective linear regression equation being Y=452.1x+65237. The limit of detection and limit of quantificationwere 4.547 and 1.377 mcg, respectively. The method was validated by determining its accuracy, precision, and system suitability.Result: The objective of the present work is to develop simple, precise, and reliable HPLC method for the analysis of modafinil in bulk andpharmaceutical dosage forms. This is achieved using the most commonly employed Xterra RP 18 (250 mm × 4.6 mm, 5 μ particle size) columndetection at 260 nm. The present method was validated according to ICH guidelines.Conclusion: In this study, a simple, fast and reliable HPLC method was developed and validated for the determination of modafinil in pharmaceuticalformulations.Keywords: Modafinil, Reversed-phase high-performance liquid chromatography, Estimation, ICH guidelines, Tablets. 

scholarly journals The Waste Recycling of Sugarcane Bagasse-Based Biochar for Biogas Purification

2021 ◽  
Vol 940 (1) ◽  
pp. 012029
Author(s):  
M A Wuri ◽  
A Pertiwiningrum ◽  
R Budiarto ◽  
M Gozan ◽  
A W Harto
Keyword(s):  
Carbon Dioxide ◽  
Sugarcane Bagasse ◽  
Natural Zeolite ◽  
Pressure Range ◽  
Room Temperature ◽  
Waste Recycling ◽  
Biomass Waste ◽  
Before And After ◽  
Biogas Purification ◽  
The Difference

Abstract The utilization of the recycling of biomass waste for carbon dioxide (CO2) adsorption in biogas is still rare. Even though the experiments on the biogas purification still using synthetic biogas. This paper investigated the recycling of biomass waste, sugarcane bagasse for biogas purification. The conversion of biomass into biochar was claimed to expand the surface area of its pores for capturing CO2 in biogas. Five treatments of adsorbents used in this study, 100% volume of zeolite or biochar, 75% volume of zeolite and 25% biochar, 50% volume of zeolite and biochar, 25% volume of zeolite and 25% volume of zeolite, and 25% volume of biochar. The difference of volume treatment in adsorbents affected methane (CH4) and CO2 composition of biogas. Biogas purification by adsorption was conducted at 5-7 bar pressure range and room temperature. Biogas before and after purification were tested of CH4 and CO2 composition by gas chromatography. A significant reduction in CO2 was shown when 50% volume of zeolite was replaced by biochar. The highest in CO2 reduction showed by the composition of 50% sugarcane bagasse-based biochar and 50% natural zeolite. The CO2 decreases did not accompany by the CH4 increases because mesopore-sized still dominated the adsorbents’ pore size.

scholarly journals VARIASI WAKTU KONTAK ARANG AKTIF UNTUK MENURUNKAN BILANGAN PEROKSIDA PADA MINYAK GORENG BEKAS PAKAI

2021 ◽  
Vol 5 (1) ◽  
pp. 104-110
Author(s):  
Tuti Rustiana ◽  
Dinar Rahayu
Keyword(s):  
Particle Size ◽  
Peroxide Value ◽  
Activated Charcoal ◽  
Contact Time ◽  
Sodium Thiosulfate ◽  
Used Cooking Oil ◽  
Cooking Process ◽  
Significant Difference ◽  
Before And After ◽  
The Difference

Vegetable oil in the cooking process usually is used multiple times to fry food. This process exposes the oil to heat and oxidation. The oil itself is lipid. Lipid is a triglyceride, which means three carboxylic acids are bonded to one molecule of glycerol to form of ester. Exposing triglyceride to heat and oxidation causes it to deteriorate and break into smaller molecules such as aldehyde, ketones, and hydrocarbons. This molecule causes rancidity. Rancidity can be measured in terms of the amount of hydroperoxide presents in oil in mEq of O2/Kg. The peroxides present oxidize the iodide to iodine and the iodine is then titrated to a colorimetric endpoint using sodium thiosulfate with starch as an indicator. The amount of iodine produced is directly proportional to the peroxide value. The research has been conducted to reduce the peroxide value of used cooking oil using adsorption. The adsorbent used here is activated charcoal with a concentration of 3% and particle size of 100 Mesh. Contact time with oil is varied, ranged from 30 to 90 minutes. Statistic treatment of t-student test is performed between peroxide value before and after treatment and it is found that the difference is significant. That means active charcoal can decrease peroxide value. One way of ANOVA test among contact times (30, 60, 90 minutes) proves there is no significant difference, leading to the conclusion that activated charcoal at 3% and particle size 100 Mesh can decrease the peroxide value of oil in only 30 minutes of contact time.

Processing of High Performance Silicon Carbide

2008 ◽  
Vol 403 ◽  
pp. 165-168 ◽  
Author(s):  
Yoshihiro Hirata ◽  
Naoki Matsunaga ◽  
Nobuhiro Hidaka ◽  
Shuhei Tabata ◽  
Soichiro Sameshima
Keyword(s):  
Fracture Toughness ◽  
Particle Size ◽  
High Performance ◽  
Weibull Modulus ◽  
Aqueous Suspension ◽  
Liquid Phase Sintering ◽  
Precipitation Mechanism ◽  
Precursor Polymer ◽  
Sic Particles ◽  
Positively Charged

Liquid phase sintering based on the dissolution-precipitation mechanism was applied to densify a 0.8 μm SiC powder with alumina (1.2 vol%)-yttria (0.9-3.3 vol%) additives. To uniformly distribute the sintering additives around the SiC particles, a heterocoagulated particle network was formed among negatively charged SiC particles, positively charged 0.2 μm alumina and yttrium ions in an aqueous suspension at pH 5. Yttrium ions were electrostatically adsorbed on the negatively charged SiC surfaces. The consolidated green compacts were highly sintered to 97-99 % of theoretical density by hot-pressing at 1950 °C. Four-point strength, fracture toughness and Weibull modulus were highly enhanced when a bimodal particle size system of SiC (75 vol% 0.8 micrometer-25 vol% 30 nanometer SiC) was sintered. The maximum strength reached 1.1 GPa. The fracture toughness was about 6 MPa•m1/2 and the Weibull modulus was 5.9. When a small amount of SiC precursor polymer was infiltrated in the green compact, the strength and Weibull modulus were further improved.

Standardization of Glycohemoglobin Determinations in the Clinical Laboratory: Three Years of Experience

1992 ◽  
Vol 38 (12) ◽  
pp. 2414-2418 ◽  
Author(s):  
G S Bodor ◽  
R R Little ◽  
N Garrett ◽  
W Brown ◽  
D E Goldstein ◽  
...  
Keyword(s):  
Affinity Chromatography ◽  
Analytical Methods ◽  
High Performance ◽  
Clinical Laboratory ◽  
Hplc Method ◽  
Diabetic Patients ◽  
Years Of Experience ◽  
Chromatography Method ◽  
Before And After

Abstract Measurement of glycohemoglobin has been recommended for the long-term assessment of glycemic control in diabetic patients. Because different analytical methods measure different glycohemoglobin species, it has been difficult to compare results between laboratories. Here we report 3 years of experience with calibration of an affinity chromatography method for measuring total glycohemoglobin (GHb). Calibration was achieved by including in each assay three hemolysate calibrators for which values for HbA1c and GHb had been determined by repeated analyses by high-performance liquid chromatography (HPLC) and affinity chromatography, respectively. Calibration improved interassay precision (CV = 3.20-7.90% and < 5.0% before and after the introduction of calibration, respectively) and eliminated lot-to-lot variability. In 91 samples, HbA1c was estimated by the calibrated affinity chromatography assay and measured by an ion-exchange HPLC method. Estimated and HPLC-measured HbA1c showed no clinically significant differences during 36 months. The high degree of long-term precision, the disappearance of lot-to-lot variability, and the excellent comparability between analytical methods measuring different species of glycated hemoglobins demonstrate the advantages of calibration.

Simultaneous liquid-chromatographic determination of prednisone and prednisolone in plasma.

1988 ◽  
Vol 34 (9) ◽  
pp. 1897-1899 ◽  
Author(s):  
M H Cheng ◽  
W Y Huang ◽  
A I Lipsey
Keyword(s):  
High Performance ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Hplc Method ◽  
Liquid Chromatographic Determination ◽  
Standard Solution ◽  
Liquid Chromatographic

Abstract This high-performance liquid-chromatographic (HPLC) method for simultaneous determination of prednisone and its metabolite, prednisolone, in plasma is a modification of the method of Frey et al. (Clin Chem 1979;25:1944-7). Heparinized plasma (1.0 mL) with 0.1 mL of internal standard solution (11-deoxy-17-hydroxycorticosterone, 2 mg/L) is extracted with 7.0 mL of dichloromethane, then washed sequentially with 0.1 mol/L HCl, 0.1 mol/L NaOH, and deionized water, 2.0 mL each. The extract is evaporated and the residue reconstituted with 75 microL of mobile phase, methanol/H2O (40/60 by vol). Thirty microliters of this is injected onto a reversed-phase C6 column, which is eluted at 1.4 mL/min. Analytical recoveries of prednisone and prednisolone were 94-98% and 102-106%, respectively. Day-to-day precision (CV) was 3.8% for prednisone, 6.1% for prednisolone. We encountered no interference from the 21 other steroids and 25 drugs tested. This method is simple, accurate, and precise.

scholarly journals Characterization, purity assessment, and preparation of liposomal formulation of 2,4,6-trihydroxygeranylacetophenone

2020 ◽  
Vol 19 (10) ◽  
pp. 2025-2032
Author(s):  
Yamen Alkhateeb ◽  
Qais B. Jarrar ◽  
Faridah Abas ◽  
Yaya Rukayadi ◽  
Khozirah Shaari
Keyword(s):  
Particle Size ◽  
High Performance ◽  
Encapsulation Efficiency ◽  
Water Solubility ◽  
Analytical Techniques ◽  
Spectroscopic Characterization ◽  
Hplc Method ◽  
Liposomal Formulation ◽  
Poor Solubility ◽  
Quantitative Nuclear Magnetic Resonance

Purpose: To prepare, characterize, and determine the purity of 2,4,6-trihydroxygeranylacetophenone (tHGA), and also to develop and characterize a liposomal formulation of tHGA to overcome its poor water solubility. Methods: The tHGA was synthesized and then purified in two steps using two types of column chromatography separation techniques. The compound was characterized using different analytical techniques, while the purity of tHGA was determined by quantitative-nuclear magnetic resonance (qNMR). Proliposomes method was developed to produce liposome-encapsulated tHGA which was characterized based on particle size, polydispersity, stability, and encapsulation efficiency. A selective and rapid high-performance liquid chromatography (HPLC) method was developed and validated to quantify tHGA in a liposomal formulation in order to evaluate the encapsulation efficiency. Results: The tHGA was successfully prepared and characterized with 98.4 % purity. A simple and reproducible proliposomes method was successfully developed to produce liposome-encapsulated tHGA. The liposomal formulation exhibited excellent encapsulation efficiency (90.4 %). This formulation also yielded a homogenous liposome population (polydispersity index = 0.39) with a small particle size (250.8 nm). The prepared liposome-encapsulated tHGA was stable at refrigerated temperature (4 ºC) for at least four weeks. The developed HPLC method showed good linearity over the range of 10 to 500 μg/mL with high precision and accuracy. Conclusion: The compound produced has a high purity which can be used as an analytical reference standard. The developed formulation is  effective for dissolving and entrapping a high amount of tHGA which helps to overcome its poor solubility. Keywords: Liposomes, Proliposomes, Trihydroxygeranylacetophenone, tHGA, Spectroscopic characterization, Poor solubility

scholarly journals Development of RP-HPLC Method for the Simultaneous Quantitation of Levamisole and Albendazole: Application to Assay Validation

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
S. Sowjanya ◽  
Ch. Devadasu
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Standard Addition ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Simultaneous Estimation ◽  
Limit Of Quantification ◽  
Rp Hplc ◽  
Standard Solution ◽  
Liquid Chromatographic

A reverse phase high-performance liquid chromatographic (RP-HPLC) method was developed and validated for simultaneous estimation of levamisole and albendazole in drug substance and in its combinational dosage form. The analysis was carried out usingInertsil ODSC18(4.6 x 150 mm, 5μm) column, and the separation was carried out using a mobile phase containing a buffer of pH 3.5 and acetonitrile (70:30 v/v) pumped at a flow rate of 1.0 mL/min with variable wavelength UV-detection at 224 nm. Both the drugs were well resolved in the stationary phase and the retention times were 2.350 min and 4.055 for levamisole and albendazole, respectively. The method was validated and shown to be linear in the concentration range of 15-45μg/ml and 40-120μg/ml for levamisole and albendazole, respectively. The limit of detection (LOD) and limit of quantification (LOQ) were determined based on standard deviation of the y-intercept and the slope of the calibration curve. LOD and LOQ values were 2.08μg/ml and 6.03μg/ml for levamisole and 3.15μg/ml and 10.40μg/ml for albendazole, respectively. The accuracy of the method was assessed by adding known amount of standard solution (75 %, 100 %, and 125% of the sample concentration) to the preanalyzed sample solution of 100% concentration. All the samples were prepared and analyzed in triplicate. The percentage mean recovery by standard addition experiments of levamisole and albendazole is 99.66% and 98.73%, respectively.

Effects of bilirubin photoisomers on the measurement of direct bilirubin by the bilirubin oxidase method

2017 ◽  
Vol 55 (2) ◽  
pp. 276-280 ◽  
Author(s):  
Hitoshi Okada ◽  
Kou Kawada ◽  
Susumu Itoh ◽  
Miyo Ozaki ◽  
Isami Kakutani ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
High Performance ◽  
Direct Bilirubin ◽  
Serum Samples ◽  
Bilirubin Concentration ◽  
Bilirubin Oxidase ◽  
The Past ◽  
Room Light ◽  
Before And After ◽  
The Difference

Background We occasionally encounter increases in direct bilirubin value on reanalysis of the surplus serum collected in the past from a neonate with indirect hyperbilirubinemia. But the details of this phenomenon are unclear. We evaluated the change of direct bilirubin and the relation of bilirubin photoisomer of the serum exposed to room light. Methods Surplus serum samples from neonates with indirect hyperbilirubinemia were exposed to room light for 24 h. The bilirubin fraction assay of samples was performed by the bilirubin oxidase method (Nescauto and Aqua-auto Kainos reagent) and high-performance liquid chromatography. Results Direct bilirubin increased significantly from 0.61 to 2.36 mg/dL. The respective ratios of bilirubin photoisomers before and after exposure were as follows: cyclobilirubin (0.007 to 0.29) and (EZ)-bilirubin (0.018 to 0.041) increased significantly, (ZZ)-bilirubin decreased 0.84 to 0.55 significantly. The difference of the cyclobilirubin concentration was most closely associated with those of the direct bilirubin concentration. Conclusion Direct bilirubin value was increased after exposure to the room light, and increase in direct bilirubin was significantly correlated by cyclobilirubin increase in the serum samples from neonates with indirect hyperbilirubinemia.

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