scholarly journals Determination of Potassium, Sodium, and Total Alkalies in Portland Cement, Fly Ash, Admixtures, and Water of Concrete by a Simple Flow Injection Flame Photometric System

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Jaroon Junsomboon ◽  
Jaroon Jakmunee

A simple flow injection with flame photometric detection has been developed for determination of sodium, potassium, and total alkalies in portland cement, fly ash, admixtures, and water of concrete. A liquid sample or a digest of solid sample was injected into a water carrier stream which flowed to a flame photometer. A change in emission intensity at a selected wavelength was recorded as a peak. An amplifier circuit was fabricated, which helped improve sensitivity of the flame photometer. Calibration graphs in the range of 0.05–1.0 mg L−1and 1.0–20.0 mg L−1were obtained with a detection limit of 0.02 mg L−1, for both potassium and sodium determination. Relative standard deviations for 11 replicates of injecting of 10 mg L−1potassium and sodium solutions were 1.69 and 1.79%, respectively. Sample throughput of 120 h−1was achieved. The proposed method was successfully applied to portland cement, fly ash, admixtures, and water samples validated by the ASTM standard method and certified reference materials of portland cement.

2010 ◽  
Vol 113-116 ◽  
pp. 1732-1734
Author(s):  
Xin Zhao ◽  
Zhi Hui Sui ◽  
Jing Bin Zhang

In 1.0 mol/L H2SO4 solution, a rapid and simple flow—injection spectrophotometric method has been developed for Cr(Ⅵ) determination, based on the violet—red Cr(Ⅵ)—diphenylcarbazide chelates formed by reactions. The results show, under optimum conditions, the maximum absorption of the complex is at 540 nm and the detection limits of the method is 0.0136mg/L for Cr(Ⅵ) and Beer’s law is obeyed for Cr(Ⅵ) in the range of 0.03—1.60mg/L. The determination frequency is l00 times/h. The relative standard deviation of eleven replicates is less than 4.0%. The method has been applied to the determination of trace Cr(Ⅵ) in tanning wastewater with satisfactory results.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Xiaocui Duan ◽  
Pingping Zhang ◽  
Jing Feng ◽  
Ning Jiao

The study based on the chemiluminescence (CL) reaction of potassium ferricyanide and luminol in sodium hydroxide medium, enrofloxacin (ENRO) could dramatically enhance CL intensities and incorporated with matrix solid-phase dispersion (MSPD) technique (Florisil used as dispersant, dichloromethane eluted the target compounds). A simple flow injection chemiluminescence (FL-CL) method with MSPD technique for determination of ENRO in eggs was described. Under optimal conditions, the CL intensities were linearly related to ENRO concentration ranging from4.0×10-8 g.L−1to5.0×10-5 g.L−1, with a correlation coefficient of 0.9989 and detection limit of5.0×10-9 g.L−1. The relative standard deviation was 3.6% at an ENRO concentration of2.0×10-6 g.L−1. Our testing technique can help ensure food safety, and thus, protect public health.


2006 ◽  
Vol 60 (4) ◽  
Author(s):  
X. Xie ◽  
X. Shao ◽  
Z. Song

AbstractA simple flow-injection chemiluminescence method with synergistic enhancement has been investigated for the rapid and sensitive determination of antipsychotic risperidone. The synergistic action was significant in the chemiluminescence system of luminol—hydrogen peroxide with risperidone as an enhancer. The increased chemiluminescence intensity was correlated with risperidone concentration within the range from 10 pg mL−1 to 1.0 ng mL−1 with relative standard deviations lower than 5.0 % and the detection limit of 4 pg mL−1. At a flow rate of 2.0 mL min−1, the flow-injection chemiluminescence method exhibited both a high sensitivity and excellent selectivity giving a throughput of 120 times per hour. The proposed method was successfully applied to determine the risperidone content in human urine without any pretreatment. It was found that the excretive amounts of risperidone reached their maximum after taking 2.0 mg of risperidone for 1 h, with a total excretive ratio of 17.37 % in 8.5 h.


2012 ◽  
Vol 48 (2) ◽  
pp. 325-333 ◽  
Author(s):  
Fernando Campanhã Vicentini ◽  
Willian Toito Suarez ◽  
Éder Tadeu Gomes Cavalheiro ◽  
Orlando Fatibello-Filho

A simple flow-injection analysis procedure was developed for determining captopril in pharmaceutical formulations employing a novel solid-phase reactor containing silver thiocyanate immobilized in a castor oil derivative polyurethane resin. The method was based on silver mercaptide formation between the captopril and Ag(I) in the solid-phase reactor. During such a reaction, the SCN- anion was released and reacted with Fe3+, which generated the FeSCN2+ complex that was continuously monitored at 480 nm. The analytical curve was linear in the captopril concentration range from 3.0 × 10-4 mol L-1 to 1.1 × 10-3 mol L-1 with a detection limit of 8.0 × 10-5 mol L-1. Recoveries between 97.5% and 103% and a relative standard deviation of 2% for a solution containing 6.0 × 10-4 mol L-1 captopril (n = 12) were obtained. The sample throughput was 40 h-1 and the results obtained for captopril in pharmaceutical formulations using this procedure and those obtained using a pharmacopoeia procedure were in agreement at a 95% confidence level.


2009 ◽  
Vol 63 (3) ◽  
Author(s):  
Muberra Andac ◽  
Adem Asan ◽  
Ibrahim Isildak

AbstractA simple and rapid flow-injection spectrophotometric method for the determination of iron(III) and total iron is proposed. The method is based on the reaction between iron(III) and O-acetylsalicylhydroxamic acid (AcSHA) in a 2 % methanol solution resulting in an intense violet complex with strong absorption at 475 nm. Optimum conditions for the determination of iron(III) and the interfering ions were tested. The relative standard deviation for the determination of 5 μg L−1 iron(III) was 0.85 % (n = 10), and the limit of detection (blank signal plus three times the standard deviation of the blank) was 0.5 μg L−1, both based on the injection volumes of 20 μL. The method was successfully applied in the determination of iron(III) and total iron in water and ore samples. The method was verified by analysing a certified reference material Zn/Al/Cu 43XZ3F and also by the AAS method.


1993 ◽  
Vol 15 (4) ◽  
pp. 141-146 ◽  
Author(s):  
J. S. Cosano ◽  
M. D. Luque de Castro ◽  
M. Valcárcel

This paper describes a simple flow-injection (FI) manifold for the determination of a variety of species in industrial water. The chemical systems involved in the determination of ammonia (formation of Indophenol Blue), sulfate (precipitation with Ba(II)), and iron (complexation with 1,10-phenanthroline with the help of a prior redox reaction for speciation) were selected so that a common manifold could be used for the sequential determination of batches of each analyte. A microcolumn of a suitable ion exchange material was used for on-line preconcentration of each analyte prior to injection; linear ranges for the determination of the analytes at the ng/ml levels were obtained with good reproducibility. The manifold and methods are ready for full automation.


2018 ◽  
Vol 33 (2) ◽  
pp. 47
Author(s):  
Orlando Fatibello-Filho ◽  
Heberth Juliano Vieira

A spectrophotometric flow injection method for the determination of paracetamol in pharmaceutical formulations is proposed. The procedure was based on the oxidation of paracetamol by sodium hypochloride and the determination of the excess of this oxidant using o-tolidine dichloride as chromogenic reagent at 430 nm. The analytical curve was linear in the paracetamol concentration range from 8.50 x 10-6 to 2.51 x 10-4 mol L-1 with a detection limit of 5.0 x 10-6 mol L-1. The relative standard deviation was smaller than 1.2% for 1.20 x 10-4 mol L-1 paracetamol solution (n = 10). The results obtained for paracetamol in pharmaceutical formulations using the proposed flow injection method and those obtained using a USP Pharmacopoeia method are in agreement at the 95% confidence level.


2013 ◽  
Vol 295-298 ◽  
pp. 950-953 ◽  
Author(s):  
Dong Yuan ◽  
Da You Fu ◽  
Wen Yuan Tan

A rapid spectrophotometric method for flow injection determination of sulfite in tan wastewater is described. The proposed method was based on the addition reaction of sulfite with fuchsin in Na2B4O7-NaOH medium. The optimum conditions allow a linear calibration range of 0.01-1.20 μg ml-1 SO32-. The detection limit is 0.0023μg ml-1 (S/N=3), and the relative standard deviation for night replicate measurements is 1.1% for 0.5μg ml-1 of sulfite. The sampling rate is 60 samples h-1. The procedure has been applied to the determination of sulfite in tan wastewater. The results were in good agreement with those obtained by pararosaniline method.


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