Determination of Formaldehyde Based on the Fading Reaction of Methyl Orange by Reversed Flow Injection Spectrophotometry

2013 ◽  
Vol 295-298 ◽  
pp. 479-482
Author(s):  
Ling Su ◽  
Jia Liang Guo ◽  
Zhen Liu ◽  
Lu Sheng Liu ◽  
Wei Wei

A rapid method for determination of formaldehyde in paint and indoor air by flow injection spectrophotometry based on the catalytic effects of formaldehyde on the oxidation reaction of methyl orange by potassium bromate in sulfuric acid medium was established. The relationship of the reduced absorbency to the concentration of formaldehyde was good linearity and the maximum absorption peak located at 508 nm. The affecting factors on the strength of absorption including temperature, acidity, dosage, coexisting ions and so on, and the optimal conditions of the reaction in the system were investigated. Calibration graphs were linear for ranges of 0 to 1.0 mg/L and a detection limit of 1.1×10-8 g/mL formaldehyde was achieved. The proposed method was successfully applied to the analyses of paint and indoor air samples, with relative standard deviation of less than 1.8% and the recoveries are 94.6% to 106.2%for the determination of formaldehyde.

2012 ◽  
Vol 610-613 ◽  
pp. 436-439
Author(s):  
Ling Su ◽  
Wei Wei ◽  
Jia Liang Guo ◽  
Zhen Liu ◽  
Lu Sheng Liu

A method for determination of formaldehyde by flow injection spectrophotometry based on the catalytic effects of formaldehyde on the oxidation reaction of Bordeaux R by potassium chlorate in sulfuric acid medium was established. The relationship of the reduced absorbency to the concentration of formaldehyde was good linearity and the maximum absorption peak located at 520nm. The affecting factors on the strength of absorption including acidity, dosage, temperature, coexisting ions and so on, and the optimal conditions of the reaction in the system were investigated. Calibration graphs were linear for ranges of 0 to 3.0 mg l−1 and a detection limit of 2×10-8 g ml−1 formaldehyde was achieved. The proposed method was successfully applied to the analyses of environmental samples, with relative standard deviation of less than 1.6% and the recoveries are 93.6 % to 94.5% for the determination of formaldehyde.


2014 ◽  
Vol 955-959 ◽  
pp. 1276-1279
Author(s):  
Ling Su ◽  
Heng Shen Xie

A method for determination of cobalt in water by flow injection spectrophotometry based on the catalytic effects of cobalt on the oxidation reaction of arsenazo III by potassium bichromate in HAc-NaAc buffer solution of pH 4.6 was established. The relationship of the reduced absorbency to the concentration of cobalt was good linearity and the maximum absorption peak located at 550 nm. The affecting factors on the strength of absorption including acidity, dosage, temperature, coexisting ions and so on, and the optimal conditions of the reaction in the system were investigated. Calibration graphs were linear for ranges of 0 to 20 μg/mL and a detection limit of 0.3 μg/mL cobalt was achieved. The proposed method was successfully applied to the analyses of industrial waste water samples, with relative standard deviation of less than 1.5% and the recoveries are 95.1% to 96.8%for the determination of cobalt.


2011 ◽  
Vol 356-360 ◽  
pp. 939-942
Author(s):  
Ling Su ◽  
Heng Shen Xie

A method for determination of Chromium(VI) by reversed flow injection spectrophotometry based on the catalytic effects of chromium on the oxidation reaction of methylene blue by sodium periodate in sulfuric acid medium is established. Effects of concentration of reagents and other conditions have been optimized. Calibration graphs are linear for ranges of 0 to 1.0mgl−1. A detection limit of 0.007mgl−1 chromium is achieved. The proposed method is successfully applied to the analyses of industrial waste water and electroplating waste liquor, with relative standard deviation of less than 1.5% and the recoveries are 92.9% to 97.5%for the determination of chromium.


1998 ◽  
Vol 81 (6) ◽  
pp. 1190-1201 ◽  
Author(s):  
Marvin Carlson ◽  
Richard D Thompson

Abstract An ion chromatographic (IC) method was developed for determining phosphine (PH3) in whole grains (barley, corn, oats, rice, rye, and wheat) and soybeans. The method converts phosphine to phosphate (i.e., orthophosphate) and isolates the phosphate by IC with eluent-suppressed conductivity detection. Recoveries of unbound phosphine by the method were similar to those obtained by an established colorimetric method for 7 different products fortified at 3 levels. Mean recoveries were low (i.e., 30-60%) and varied with product type and level of fortification. Recoveries of PH3 from previously fumigated products fortified with aluminum phosphide ranged from 19.0% for barley fortified at 0.734 ppm to 88.3% for corn fortified at 1.691 ppm. Precision data from 3 products based on replicate analyses (n = 4 or 5) gave relative standard deviations of 1.78-4.66% for mean laboratory-fumigated PH3 levels of 0.679-1.309 ppm. Estimated limits of detection (LOD) and quantitation (LOQ) for PH3 were 0.010 μg/g (10 ppb) and 0.0275 μg/g (27.5 ppb) at signal-to-noise ratios (S/N) of 4:1 and 10:1, respectively. These values were also determined for a nonchemically suppressed IC system with LOD of 0.02 μg/g (20 ppb) and LOQ of 0.055 μg/g (55 ppb) at S/N of 4:1 and 10:1, respectively. Phosphate response was linear over the concentration range equivalent to 0.30-10.0 fig P/mL, with a mean correlation coefficient of 0.9988 based on replicate standard curves. The relationship of product composition to recovery from various products was also examined.


2001 ◽  
Vol 84 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Yolanda Fuster Mestre ◽  
Luis Lahuerta Zamora ◽  
José Martínez Calatayud

Abstract A new method is proposed for the determination of phenylephrine hydrochloride by flow injection analysis with direct chemiluminescence detection. The method is based on the oxidation of the drug by potassium permanganate in sulfuric acid medium at 80°C. The calibration graph is linear over the range 0.03–8 ppm phenylephrine hydrochloride, with a relative standard deviation (n = 51, 0.5 ppm) of 1.1% and sample throughput of 134/h. The influence of 38 different foreign compounds was tested, and the method was applied to the determination of phenylephrine hydrochloride in 8 different pharmaceutical formulations.


2012 ◽  
Vol 34 (3) ◽  
pp. 169-184 ◽  
Author(s):  
Hoang Thi Bich Ngoc

Vertical axis wind turbine technology has been applied last years, very long after horizontal axis wind turbine technology. Aerodynamic problems of vertical axis wind machines are discussible. An important problem is the determination of the incidence law in the interaction between wind and rotor blades. The focus of the work is to establish equations of the incidence depending on the blade azimuth, and to solve them. From these results, aerodynamic torques and power can be calculated. The incidence angle is a parameter of velocity triangle, and both the factors depend not only on the blade azimuth but also on the ratio of rotational speed and horizontal speed. The built computational program allows theoretically selecting the relationship of geometric parameters of wind turbine in accordance with requirements on power, wind speed and installation conditions.


1986 ◽  
Vol 14 (4) ◽  
pp. 201-218 ◽  
Author(s):  
A. G. Veith

Abstract This four-part series of papers addresses the problem of systematic determination of the influence of several tire factors on tire treadwear. Both the main effect of each factor and some of their interactive effects are included. The program was also structured to evaluate the influence of some external-to-tire conditions on the relationship of tire factors to treadwear. Part I describes the experimental design used to evaluate the effects on treadwear of generic tire type, aspect ratio, tread pattern (groove or void level), type of pattern (straight rib or block), and tread compound. Construction procedures and precautions used to obtain a valid and functional test method are included. Two guiding principles to be used in the data analyses of Parts II and III are discussed. These are the fractional groove and void concept, to characterize tread pattern geometry, and a demonstration of the equivalence of wear rate for identical compounds on whole tread or multi-section tread tires.


2016 ◽  
Vol 11 (3) ◽  
pp. 802-810 ◽  
Author(s):  
Nitin Yashwant Patil ◽  
Ravi M. Warkhedkar

Purpose In the past decade, much has been written about knowledge management (KM) in the manufacturing; however, less attention has been paid to the Indian automobile ancillary industries located in Chinchwad, Pune. It is suitable to find out the relationship of the factors of the study. It helps in identifying the hierarchy of factors to be taken, and interlinking of production department with KM improves the productivity of the industries. Categorization of these principles based on their driving power (principles which hold other principles) and dependence (principles which are dependent on other principles) has also been examined for KM implementation to study the driving power and dependence power of these principles. This paper aims to determine the roadmap of KM implementation and categorize KM principles based on their driving power for manufacturing industries with the use of the interpretive structural modeling (ISM)-based model. The results indicate that the principles possessing higher driving power, such as KM, inventory control, quality control, productivity and scheduling and their interlinking. The major contribution of this research lies in the development of contextual relationship among various identified factors of KM and determination of their driving and dependence power through a single systemic framework. Design/methodology/approach In this paper, author find out the suitability ISM for Indian Automobile industries to find the relation among the variables. Findings ISM model has been developed for the hierarchy of the identified KM. As ISM model results a hypothetical hierarchy which needs a proper quantitative analysis to evaluate their percentage effectiveness in the hierarchy. Research limitations/implications It is applied to automobile industries with limited number of variables that will show the dependence variable and driving variables and their interrelations. It can be applied other fields to fine the relationship of variables. Practical implications The ISM may be used in supply chain management and total quality management to find interlinking between the variables. Originality/value The limited data collected from Pimpri Chinchwad industrial area of Pune from Maharashtra state (India).


2021 ◽  
Vol 26 (3) ◽  
pp. 34-39
Author(s):  
Z. A. Goncharova ◽  
Y. Y. Pogrebnova ◽  
N. M. Yarosh ◽  
S. M.M. Sehweil

The article presents the literature review and our experience in early diagnosis of multiple sclerosis based on the updated McDonald criteria of 2017. The study included 256 patients with clinic symptoms of probable idiopathic infl ammatory demyelinating disease, including rare and atypical forms of demyelination. As a result of the study the sensitivity and specifi city of the determination of oligoclonal immunoglobulin G in the population of Rostov-on-Don was described for the fi rst time, including dependence of the duration of the disease. The relationship of clinical and MRI features of the fi rst attack of the disease with the probability of determining oligoclonal IgG in the cerebrospinal fl uid is refl ected


2015 ◽  
Vol 60 (11) ◽  
pp. 1-15
Author(s):  
Olga Leszczyńska-Luberek

The author presents the importance of the new European System of National and Regional Accounts (ESA 2010) for statistics of the general government sector. She pays particular attention to the development of data for the excessive deficit procedure. The article explains the methodological changes made to the studies in this field parallel to the ESA 2010. It discusses, among others, issues related to defining the deficit and debt of the general government, as well as the determination of a new way registering transfer of liabilities of pension schemes. It also presents the impact of new methodological guidelines for the relationship of deficit and debt to GDP in the Member States of the European Union.


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