scholarly journals A Full Automatic Device for Sampling Small Solution Volumes in Photometric Titration Procedure Based on Multicommuted Flow System

2007 ◽  
Vol 2007 ◽  
pp. 1-6
Author(s):  
Sivanildo S. Borges ◽  
Gláucia P. Vieira ◽  
Boaventura F. Reis
Keyword(s):  
Flow System ◽  
Sodium Hydroxide Solution ◽  
Glass Tube ◽  
Automatic Device ◽  
Vertical Position ◽  
Good Precision ◽  
Small Solution ◽  
Relative Standard ◽  
Photometric Titration ◽  
Solution Volume

In this work, an automatic device to deliver titrant solution into a titration chamber with the ability to determine the dispensed volume of solution, with good precision independent of both elapsed time and flow rate, is proposed. A glass tube maintained at the vertical position was employed as a container for the titrant solution. Electronic devices were coupled to the glass tube in order to control its filling with titrant solution, as well as the stepwise solution delivering into the titration chamber. The detection of the titration end point was performed employing a photometer designed using a green LED (λ= 545 nm) and a phototransistor. The titration flow system comprised three-way solenoid valves, which were assembled to allow that the steps comprising the solution container loading and the titration run were carried out automatically. The device for the solution volume determination was designed employing an infrared LED (λ= 930 nm) and a photodiode. When solution volume delivered from proposed device was within the range of 5 to 105μl, a linear relationship (R = 0.999) between the delivered volumes and the generated potential difference was achieved. The usefulness of the proposed device was proved performing photometric titration of hydrochloric acid solution with a standardized sodium hydroxide solution and using phenolphthalein as an external indicator. The achieved results presented relative standard deviation of 1.5%.

scholarly journals Instrumentation and Automated Photometric Titration Procedure for Total Acidity Determination in Red Wine Employing a Multicommuted Flow System

2006 ◽  
Vol 2006 ◽  
pp. 1-8 ◽  
Author(s):  
Ausberta Jesus Cabezas Garcia ◽  
Boaventura F. Reis
Keyword(s):  
Red Wine ◽  
Flow System ◽  
Reference Method ◽  
Total Acidity ◽  
Real Time Processing ◽  
Photometric Detection ◽  
Titration Procedure ◽  
Relative Standard ◽  
Significant Difference ◽  
Photometric Titration

An automated procedure for photometric titration of red wine and associated instrumentation is described. The procedure was based on the flow-batch approach implemented employing multicommutation. The photometric detection was carried out using a homemade LED-based photometer. The mixing device, LED, and photodetector were attached to the titration chamber in order to form a compact and small-sized unit. The flow system comprised an automatic injector and three-way solenoid valves, which were controlled by a microcomputer through an electronic interface card. The software, written in Quick BASIC 4.5, was designed with abilities to accomplish all steps of the titration procedure including data acquisition and real-time processing to decide about the course of titration in the following step and so forth, until the titration endpoint was reached. The usefulness of the proposed titration system was demonstrated by analyzing red wine samples. When results were compared with those obtained using the AOAC reference method, no significant difference was observed at the95%confidence level. A relative standard deviation of ca 2%(n=9) was obtained when processing a typical red wine sample containing 7.3gl-1total acidity expressed as tartaric acid.

Validation of A Simple HPLC-UV Method For the Quantification of Andrographolide in Self-Nano Emulsifying Drug Delivery System (Snedds) For Dissolution Study

2017 ◽  
Vol 7 (04) ◽  
Author(s):  
Syukri Y ◽  
Afetma D. W. ◽  
Sirin M. ◽  
Fajri R. ◽  
Ningrum A. D. K. ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Delivery System ◽  
Gastric Fluid ◽  
Hplc Method ◽  
Good Precision ◽  
Intestinal Fluid ◽  
Dissolution Medium ◽  
Relative Standard ◽  
Sufficient Precision

This research aim to validation of a simple, rapid and accurate HPLC-UV method for the quantification of andrographolide isolated from Andrographis paniculata Ness in Self Nano Emulsifying Drug Delivery System (SNEDDS) formulation during the dissolution test. The assay was performed using a XTerra® MS C18 column (150 mm X 4.6 mm, five μm) with a mobile phase of methanol and water (70: 30), at 0.8 mL/min flow rate and UV detection of 229 nm. Simulation gastric fluid (SGF) and intestinal fluid (SIF) were prepared as dissolution medium. The validation parameter was conducted including the test on linearity, precision, accuracy, LOD, and LOQ. The result showed an excellent linearity with r = 0.999 and good selectivity for both medium dissolution. The method showed sufficient precision, with a relative standard deviation (RSD) smaller than % Horwitz. The accuracy reported as % recovery was found to be 102.61 and 101.17 % in each SGF and SIF dissolution medium. LOD and LOQ were found 0.46 and 1.40 in SGF medium, 0.87 and 2.64 in SIF medium. In conclusion, the HPLC method developed showed specificity and selectivity with linearity in the working range, good precision and accuracy and suitable for quantification andrographolide in SNEDDS formulation.

Determination of Epsilon Aminocaproic Acid Based on Charge Transfer Complexation with p-Nitrophenlol by Spectrophotometry

2020 ◽  
Vol 16 ◽  
Author(s):  
Sheng-Yun Li ◽  
Fang Tian
Keyword(s):  
Charge Transfer ◽  
Aminocaproic Acid ◽  
Concentration Limit ◽  
Official Method ◽  
Good Precision ◽  
Pharmaceutical Dosage Forms ◽  
Relative Standard ◽  
A Charge ◽  
Epsilon Aminocaproic Acid

: A spectrophotometry was investigated for the determination of epsilon aminocaproic acid (EACA) with p-nitrophenol (PNP). The method was based on a charge transfer (CT) complexation of this drug as n-electron donor with π-acceptor PNP. Experiment indicated that the CT complexation was carried out at room temperature for 10 minutes in dimethyl sulfoxide solvent. The spectrum obtained for EACA/PNP system showed the maximum absorption band at wavelength of 425 nm. The stoichiometry of the CT complex was found to be 1:1 ratio by Job’s method between the donor and the acceptor. Different variables affecting the complexation were carefully studied and optimized. At the optimum reaction conditions, Beer’s law was obeyed in a concentration limit of 1～6 µg mL-1. The relative standard deviation was less than 2.9%. The apparent molar absoptivity was determined to be 1.86×104 L mol-1cm-1 at 425 nm. The CT complexation was also confirmed by both FTIR and 1H NMR measurements. The thermodynamic properties and reaction mechanism of the CT complexation have been discussed. The developed method could be applied successfully for the determination of the studied compound in its pharmaceutical dosage forms with a good precision and accuracy compared to official method as revealed by t- and F-tests.

scholarly journals Determination of uranium in tree bark samples by epithermal neutron activation analysis

2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Nicole Pereira de Lima ◽  
Mitiko Saiki
Keyword(s):  
Neutron Activation Analysis ◽  
Activation Analysis ◽  
Neutron Activation ◽  
Reference Materials ◽  
Epithermal Neutron ◽  
Certified Reference Materials ◽  
Tree Bark ◽  
Good Precision ◽  
Epithermal Neutron Activation Analysis ◽  
Relative Standard

In this study uranium (U) concentrations were determined in certified reference materials (CRMs) and in tree bark samples collected in “Cidade Universitária Armando de Salles Oliveira” (CUASO) USP, São Paulo. The barks were collected from different species namely Poincianella pluviosa and Tipuana tipu. These bark samples were cleaned, dried, grated and milled for the analyses by epithermal neutron activation analysis method (ENAA). This method consists on irradiating samples and U standard in IEA-R1 nuclear reactor with thermal neutron flux of 1.9 x 1012 n cm-2 s-1 during 40 to 60 seconds depending on the samples’ matrices. The samples and standard were measured by gamma ray spectroscopy. U  was identified by the peak of  74.66 keV of 239U with half life of 23.47 minutes. Concentration of U was calculated by comparative method. For analytical quality control of U results, certified reference materials were analyzed. Results obtained for CRMs presented good precision and accuracy, with |Z score| ≤ 0.39. Uranium concentrations in tree barks varied from 83.1 to 627.6 ng g-1 and the relative standard deviations of these results ranged from 1.8 to 10 %.

Copper Amalgam Working Electrode for Voltammetric Determination of Selenite

2021 ◽  
Vol 874 ◽  
pp. 35-44
Author(s):  
Ria Sri Rahayu ◽  
Meuthia Khelfa Pramesti ◽  
Adib Hasanawi ◽  
Dian Ayu Setyorini ◽  
Muhammad Yudhistira Azis
Keyword(s):  
Statistical Tests ◽  
Stripping Voltammetry ◽  
Good Precision ◽  
Linear Calibration ◽  
Working Electrode ◽  
Relative Standard ◽  
Significant Difference ◽  
Square Wave Stripping Voltammetry ◽  
Recovery Percentage ◽  
Aas Method

Selenium is one of the heavy metal pollutants in the aquatic environment. Selenite is a form of inorganic selenium, which is very poisonous to living things. Therefore, we need a method that selectively identify selenite to determine its concentration in water. In this study, a square wave stripping voltammetry was used to measure selenite concentration using copper amalgam working electrode. The optimum measurement parameters were obtained at a deposition potential of –450 mV and a deposition time of 800 seconds. This analysis method had good precision with a relative standard deviation (% RSD) of 4.89%. Linear calibration curves are shown in the range 0.03 mM – 0.10 mM with R2 of 0.988 and in the range of 0.10 mM – 0.70 mM with R2 of 0.995 and a detection limit of 9.0 µM. The standard selenite solution was measured with a recovery percentage of 96.67%. The same solution was measured using the HG-AAS method and the recovery percentage was 96.35%. Statistical tests using the t-test showed that the two results did not have a significant difference with a 95% confidence limit. Thus, the voltammetry method using copper amalgam working electrode can be used as an alternative method for determining selenite, as it is cheaper and simpler than the HG-AAS method.

scholarly journals ISOLATION, CHARACTERIZATION AND VALIDATION OF HPLC METHOD FOR QUANTIFICATION OF BIS-[10-(2-METHYL-4H-3-THIA-4,9-DIAZABENZO[F]AZULENE)]-1,4-PIPERAZINE IN AN ANTI-PSYCHOTIC DRUG SUBSTANCE, OLANZAPINE

2018 ◽  
Vol 10 (4) ◽  
pp. 22
Author(s):  
Suresh Babu Bodempudi ◽  
Ravi Chandra Babu Rupakula ◽  
Konda S. Reddy ◽  
Mahesh Reddy Ghanta
Keyword(s):  
Mobile Phase ◽  
Sodium Hydroxide Solution ◽  
Linear Regression Analysis ◽  
Sodium Dodecyl ◽  
Hplc Method ◽  
Drug Substance ◽  
Phase System ◽  
Column Temperature ◽  
Relative Standard

Objective: The main objective of present study was to Isolate, characterize and validate a reverse phase high performance liquid chromatographic method was validated for quantification of bis-[10-(2-methyl-4H-3-thia-4,9-diazabenzo[f]azulene)]-1,4-piperazine in Olanzapine drug substance; it decreases the mental disorders in human body. The method is specific, rapid, precise and accurate for the separation and determination of bis-[10-(2-methyl-4H-3-thia-4,9-diazabenzo[f]azulene)]-1,4-piperazine in Olanzapine drug substance form.Methods: The bis-[10-(2-methyl-4H-3-thia-4,9-diazabenzo[f]azulene)]-1,4-piperazine of Olanzapine was resolved on a Zorbax RX-C 8, 250 mm X 4.6 mm, 5 micron column (L-1) using a mobile phase system containing 0.03 M sodium dodecyl sulphate in water pH 2.5 with 1 N sodium hydroxide solution and acetonitrile in the ratio of (Mobile phase A-52:48 v/v) and (Mobile phase B-buffer and Acetonitrile 30:70 v/v) by using the gradient program. The mobile phase was set at a flow rate of 1.5 ml/min and the volume injected was 20μl for every injection. The detection wavelength was set at 220 nm and the column temperature was set at 35 °C.Results: The proposed method was productively applied for the quantitative determination of bis-[10-(2-methyl-4H-3-thia-4,9-diazabenzo [f]azulene)]-1,4-piperazine in Olanzapine drug substance form. The linear regression analysis data for calibration plots showed a good linear relationship over a concentration range of 0.025to 0.903 µg/ml for bis-[10-(2-methyl-4H-3-thia-4,9-diazabenzo[f]azulene)]-1,4-piperazine, 0.081-0.608 µg/ml for Olanzapine. The mean values of the correlation coefficient were 0.999 and 0.999 for bis-[10-(2-methyl-4H-3-thia-4,9-diazabenzo[f]azulene)]-1,4-piperazine and Olanzapine. The method was validated as per the ICH guidelines. The detection limit (LOD) was about 0.007 µg/ml, 0.024 µg/ml and quantitation limit (LOQ) was about 0.024 µg/ml, 0.081 µg/ml for bis-[10-(2-methyl-4H-3-thia-4,9-diazabenzo[f]azulene)]-1,4-piperazine and Olanzapine. The relative standard deviation was found to be 1.64 % and 2.18 % for bis-[10-(2-methyl-4H-3-thia-4,9-diazabenzo[f]azulene)]-1,4-piperazine and Olanzapine.Conclusion: The validated HPLC method and the statistical analysis showed that the method is repeatable and selective for the estimation of the bis-[10-(2-methyl-4H-3-thia-4,9-diazabenzo[f]azulene)]-1,4-piperazine of the Olanzapine drug substance.

scholarly journals High-Performance Thin-Layer Chromatography with Densitometry for the Determination of Ciprofloxacin and Impurities in Drugs

2005 ◽  
Vol 88 (5) ◽  
pp. 1530-1536 ◽  
Author(s):  
Jan Krzek ◽  
Urszula Hubicka ◽  
Justyna Szczepańczyk
Keyword(s):  
Thin Layer ◽  
High Performance ◽  
Limit Of Detection ◽  
Degradation Products ◽  
Pharmaceutical Preparations ◽  
High Sensitivity ◽  
Good Precision ◽  
Relative Standard ◽  
Tlc Plates ◽  
Quantitative Analyses

Abstract A thin-layer chromatographic (TLC)-densitometric method has been developed for identification and quantification of ciprofloxacin (Rf = 0.61) and an ethylenediamine compound (Rf = 0.42), a desfluoro compound (Rf = 0.48), by-compound A (Rf = 0.53), and fluoroquinolonic acid (Rf = 0.68) as ciprofloxacin degradation products in pharmaceutical preparations. By using chloroform–methanol–25% ammonia (43 + 43 + 14, v/v/v) as the mobile phase and silica gel 60 F254 high-performance TLC plates as the stationary phase, it was possible to separate individual constituents that, when subjected to ultraviolet (UV) densitometric analysis at 330 nm for fluoroquinolonic acid and 277 nm for the other compounds, gave well developed peaks allowing easy qualitative and quantitative analyses. DMSO–methanol (1 + 1) was used to extract drug constituents. The method showed high sensitivity (limit of detection 10 to 44 ng), a wide linearity range (3 to 20 μg/mL), and good precision (2.32 to 6.46% relative standard deviation) and accuracy (percentage recoveries 98.62 to 101.52%) for individual constituents.

High-Performance Liquid Chromatography Determination of Acrylamide after Its Extraction from Potato Chips

2019 ◽  
Vol 25 (4) ◽  
pp. 338-344
Author(s):  
Maryam Ghalebi ◽  
Samin Hamidi ◽  
Mahboob Nemati
Keyword(s):  
Organic Solvent ◽  
Organic Phase ◽  
High Performance ◽  
Single Step ◽  
Potato Chips ◽  
Process Efficiency ◽  
Local Market ◽  
Good Precision ◽  
Time Saving ◽  
Relative Standard

Background: Acrylamide is a known carcinogenic product that has been found among the substances such as potato chips which to be processed under the heat-treatment. In order to extract amounts of acrylamide from fried chips in market, an ultrasound-assisted liquid– liquid extraction (UA-LLE) technique is proposed. The UA-LLE coupled LLE and ultrasonication in a single step. Methods: Chips samples were dissolved in an extracting organic solvent using ultrasonication to prompt transferring of acrylamide into the organic phase. As a result, the extraction time and process efficiency were significantly enhanced through increasing the collision power and mass transfer between grounded chips and organic phase. Results: Important parameters affecting the extraction efficiency such as kind of organic solvent and its volume, re-dissolving solvent and pH were optimized. This newly proposed method has been applied to determine the trace acrylamide in potato chips samples purchased from local market. Conclusion: UA-LLE is a handy, economic and time-saving method, with high extraction yield (over 103% average recovery) and good precision (lower than 15% relative standard deviation, RSD). Most importantly, it seems this method to be an ideal pre-treatment method for the extraction of acrylamide in food matrix in food quality control laboratories.

Determination of Ten Trace Element in River Deposit by ICP-OES

2013 ◽  
Vol 807-809 ◽  
pp. 196-199
Author(s):  
Ting Ting Liu ◽  
Hong Yuan Shen
Keyword(s):  
Trace Element ◽  
Standard Addition ◽  
Measured Data ◽  
Good Precision ◽  
Icp Oes ◽  
Digestion Method ◽  
Wet Digestion ◽  
Relative Standard ◽  
Precision And Accuracy

Wet digestion method had been used in river deposit of BZ profile. At the same time, Mn, Cu, Ba, Ni, Pb, Zn, Rb, V, Sr and Zr in river deposit were determined by ICP-OES. The results show that the relative standard deviations are all below 0.39%, while the recovery of standard addition is 94.3%~117.1%. The method is proved to have good precision and accuracy, and to be simple and rapid. And the measured data provide basis for paleoflood study in this area.

scholarly journals IX. On the solar variations of magnetic declination at Bombay

1869 ◽  
Vol 159 ◽  
pp. 363-386
Keyword(s):  
Circular Hole ◽  
Focal Length ◽  
Flat Glass ◽  
Glass Tube ◽  
Vertical Position ◽  
Glass Vessel ◽  
Magnetic Declination ◽  
The Government ◽  
Intelligent Assistants

1. The observations discussed in the following pages were made at the Government Observatory at Bombay, during the years 1859 to 1865, and constitute a portion of a much larger series of observations of which the remaining part is still awaiting reduc­tion. With the exception of Sundays, and eight or ten complete days in each year, the observations were taken continuously at hourly intervals throughout the period of seven years. The observers were carefully trained Brahmins, who were under the im­mediate oversight of highly intelligent assistants of the same caste. 2. The instrument used was made by Grubb of Dublin, and consists of a rectangular bar-magnet suspended horizontally, and carrying a divided scale and a lens, by means of which its position can be determined from time to time by reading the scale with a fixed telescope properly placed. The dimensions of the magnet are 15 inches by 0.86 inch by 0.25 inch, and the broad surface is made to lie horizontal; the suspension-thread was formed of about forty fibres of untwisted silk, and is 35 inches long, being protected (but not concealed from view) by a glass tube 1.3 inch in diameter: the bot­tom of the glass tube rests upon the top of a cylindrical mahogany box (8.5 inches in height) which surrounds the magnet, and the top supports a horizontal divided circle (the torsion-circle), and a brass cross piece to which the suspension-thread is attached. The tube is secured in a vertical position by a mahogany cross bar which has a circular hole in its centre that fits over the upper end of the tube, and which is fixed at its ex­tremities to two copper pillars whose feet are screwed into the marble basement of the instrument; and the upper aperture of the tube with the attachments is screened from the outer air and dust by an inverted hemispherical glass vessel. A sliding-frame which carries above a finely divided scale etched upon glass is fixed by a binding-screw near the northern extremity of the magnet, and a similar frame carrying a lens, whose focal length is about 12.7 inches, is secured to the magnet at that distance to the southward of the glass scale, so that the latter is approximately in the principal focus of the lens. The vertical lines which form the scale are equidistant and generally of uniform length; but every fifth division is slightly and every tenth division considerably prolonged, and over the tenth divisions numbers are marked in consecutive order, thus allowing a nume­rical designation to be given with facility to every point of the scale when viewed by the telescope. To permit the scale to be viewed through its lens by a telescope outside the mahogany box, the latter has two small windows of flat glass suitably inserted in its curved side, and a lamp is placed on a stool to the northward of the masonry pillar which supports the declinometer, and is kept constantly burning. The joints and crevices, and for greater security, the whole outside surface of the cylindrical box was covered with paper to keep out small spiders or other insects.

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