Photometric determination of aluminium and zinc with salicylaldehyde semicarbazone

1984 ◽  
Vol 49 (6) ◽  
pp. 1468-1473 ◽  
Author(s):  
Záviš Holzbecher ◽  
Dagmar Lipská
Keyword(s):  
Ethyl Acetate ◽  
Fluorescence Spectra ◽  
Photometric Determination ◽  
Optimum Conditions ◽  
Fluorometric Determination ◽  
Limit Of Determination ◽  
Relative Standard ◽  
Tenfold Excess ◽  
Masking Agents

The effect of some tensides on the absorption, excitation, and fluorescence spectra of Al and Zn complexes of salicylaldehyde semicarbazone in aqueous-alcoholic solutions and on their extractability into ethyl acetate has been studied. The shape of the absorption spectra is unaffected by the presence of the tensides while the time of the complex formation is shorter. The complexes are extractable into ethyl acetate in the presence of the anionactive tenside tested, sodium lauryl sulphate. The optimum conditions for the spectrophotometric and fluorometric determination of Al and Zn have been established. The limit of determination is 2 ng ml-1 (pH 3.8-4.8) for Al and 50 ng ml-1 (pH 8.4-8.6) for Zn. Using thiosulphate or fluoride as masking agents, Zn can be determined in a concentration of 2 μg ml-1 in the presence of the same quantity of Al or Cu, or in the presence of a tenfold excess of Fe, with a relative standard deviation of 1.5%.

A spectrofluorimetric method for the determination of acitretin in pharmaceuticals

2009 ◽  
Vol 63 (4) ◽  
Author(s):  
Suling Feng ◽  
Yi Zhang ◽  
Jing Fan
Keyword(s):  
Fluorescence Spectra ◽  
Hplc Method ◽  
Relative Fluorescence Intensity ◽  
Optimum Conditions ◽  
Green Fluorescence ◽  
Spectrofluorimetric Method ◽  
Highly Sensitive ◽  
Relative Standard ◽  
Effects Of Ph

AbstractA simple, rapid, and highly sensitive spectrofluorimetric method for the determination of acitretin was developed based on the strong green fluorescence of acitretin. Influence of organic solvents on the fluorescence spectra of acitretin was studied. Effects of pH, standing time, and foreign ions on the determination of acitretin were also examined. Under the optimum conditions, linear relationship between the relative fluorescence intensity and the concentration of acitretin in the range of 30.0–1100 ng mL−1 was obtained. Detection limit of this method is 9.56 ng mL−1 for acitretin. Relative standard deviation for the determination of 480 ng mL−1 of acitretin was 1.70 %. This method was used for the determination of acitretin in pharmaceuticals and the results were compared with those obtained by the HPLC method.

Determination of low concentrations of dibenzyl sulfoxide in aqueous solutions

1979 ◽  
Vol 44 (6) ◽  
pp. 1908-1917 ◽  
Author(s):  
František Vláčil ◽  
Huynh Dang Khanh
Keyword(s):  
Standard Deviation ◽  
Hydrochloric Acid ◽  
Low Flow ◽  
Optimum Conditions ◽  
Hydrochloric Acid Medium ◽  
Low Concentrations ◽  
Limit Of Determination ◽  
Relative Standard ◽  
Basic Anion

A spectrophotometric method was developed for the determination of low concentrations of sulfoxide in water, relying on the formation of a leuco-compound from the reaction of L-tryptophan with p-dimethylaminobenzaldehyde and its oxidation by sulfoxide in hydrochloric acid medium. The optimum conditions for the determination were found by using the simplex method. The calibration curve, measured at 620 nm, is linear up to the sulfoxide concentration 7.5 . 10-5 mol l-1 (i.e. 17.3 ppm), the limit of determination is 0.1 ppm, the reproducibility, expressed as the relative standard deviation (for n = 6) is 3-4%. Oxidants interfere with the determination. Nitrates can be removed by means of a strongly basic anion exchanger in the chloride form. Mixture water-acetone (6 + 1) passing with a low flow rate should be applied to the elution of the partly sorbed sulfoxide.

Rapid Determination of Sulfite by Flow Injection Analysis Based on Fuchsin′s Addition

2013 ◽  
Vol 295-298 ◽  
pp. 950-953 ◽  
Author(s):  
Dong Yuan ◽  
Da You Fu ◽  
Wen Yuan Tan
Keyword(s):  
Flow Injection ◽  
Addition Reaction ◽  
Rapid Determination ◽  
Sampling Rate ◽  
Optimum Conditions ◽  
Linear Calibration ◽  
Relative Standard ◽  
Replicate Measurements ◽  
Good Agreement

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.

scholarly journals Determination of Organophosphorous Pesticide Phosphamidon in Environmental Water with Luminol Chemiluminescence Detection

2009 ◽  
Vol 92 (3) ◽  
pp. 914-918 ◽  
Author(s):  
Aifang Li ◽  
Xiaoyu Liu ◽  
Juan Kong ◽  
Haoyu Hu ◽  
Linghui Sun ◽  
...  
Keyword(s):  
Sodium Dodecyl ◽  
Sodium Dodecyl Benzene Sulfonate ◽  
Environmental Water ◽  
Optimum Conditions ◽  
Chemiluminescence Method ◽  
Luminol Chemiluminescence ◽  
Relative Standard ◽  
Organophosphorous Pesticide ◽  
Dodecyl Benzene Sulfonate

Abstract A novel chemiluminescence method has been developed for the determination of the organophosphorous pesticide phosphamidon in environmental water samples, based on the reaction of phosphamidon with luminolH2O2 in an alkaline medium using sodium dodecyl benzene sulfonate as the enhancer. Under optimum conditions, the increased chemiluminescence intensity was proportional to the concentration of phosphamidon in the range of 0.011.0 g/mL and the detection limit was 0.0038 g/mL (3). The relative standard deviation was <2 for 0.5 g/mL phosphamidon (n = 11). The proposed method was applied to the determination of phosphamidon residue in an environmental water sample with satisfactory results. Further study was focused on the mechanism of phosphamidon, and a possible mechanism was proposed.

Fluorometric Determination of Selenium in Foods

1974 ◽  
Vol 57 (2) ◽  
pp. 368-372 ◽  
Author(s):  
Milan Ihnat
Keyword(s):  
Standard Deviation ◽  
Milk Powder ◽  
Skim Milk ◽  
Skim Milk Powder ◽  
Food Samples ◽  
Fluorometric Method ◽  
Fluorometric Determination ◽  
Relative Standard ◽  
The Mean

Abstract A fluorometric method using 2,3-diaminonaphthalene for estimating selenium has been evaluated with regard to its applicability to food samples. Charring of the sample during digestion appeared to result in losses of native and added selenium from some samples, so a modified wet digestion procedure was introduced. Digestion first in nitric acid followed by a mixture of nitric-perchloric-sulfuric acids substantially reduced the incidence of sample charring for a variety of foods. The mean apparent recovery of selenium added as selenite or selenate at 100 and 500 ng levels to 0.1 and 1.0 g corn cereal, skim milk powder, and meat and 0.1 g fish was 101.0%; the actual recovery of the same levels of selenium from standard solutions was 96.6%. For a variety of samples containing 5—750 ng native or added selenium, the standard deviation as 4.7 + 1.95 X 10-2W ng, where W = ng selenium in the sample taken for analysis. The relative standard deviation (RSD) as a function of selenium weight (ng) was 50% (10), 6.7% (100), 4.3% (200), 3.1% (400), 2.7% (600), and 2.5% (800). The detection limit (weight of selenium at which RSD = 50%) was 10 ng at a mean blank level of 25 ng.

Fluorometric Determination of Glycerol in Wine—Comparison with Other Known Procedures

1977 ◽  
Vol 60 (3) ◽  
pp. 536-540
Author(s):  
Paolo Avellini ◽  
Pietro Damiani ◽  
Giovanni Burini
Keyword(s):  
Vapor Phase ◽  
Sugar Content ◽  
Preliminary Treatment ◽  
Glycerol Content ◽  
Fluorometric Determination ◽  
Sweet Wines ◽  
Relative Standard ◽  
Standard Deviations ◽  
Trimethylsilyl Derivatives

Abstract The glycerol content of 6 wines was evaluated by using 3 different preliminary treatments and, subsequently, a variety of instrumental and chemical procedures (fluorometric, vapor phase chromatography of trimethylsilyl derivatives, volumetric, and colorimetric). The data showed that all these procedures are applicable; in particular, the fluorometric procedure, which has not been used until now, provides average recoveries of added glycerol ranging from 99.3 to 100.9%, with relative standard deviations ranging from 2.9 to 3.2%. Vapor phase chromatography provides average recoveries of added glycerol ranging from 99.8 to 100.1%, with relative standard deviations ranging from 1.0 to 2.7%. Therefore, the fluorometric procedure appears especially useful for reliable routine analyses, because it is specific for glycerol and provides results that are unaffected by preliminary treatment. Thus it allows analysis of diluted wine, when the sugar content does not exceed 5 g/L; sweet wines must undergo an ion exchange pretreatment.

scholarly journals A Highly Sensitive Spectrofluorometric Method for the Determination of a New Antidepressant Drug, Reboxetine, in Tablets

2006 ◽  
Vol 89 (4) ◽  
pp. 972-975 ◽  
Author(s):  
ArmaĞan Önal
Keyword(s):  
Antidepressant Drug ◽  
Fluorescence Emission ◽  
Calibration Graph ◽  
Control Analysis ◽  
Optimum Conditions ◽  
Highly Sensitive ◽  
Relative Standard ◽  
Spectrofluorometric Method ◽  
Interday Precision

Abstract A highly sensitive, selective, and rapid spectrofluorometric method has been developed for the determination of reboxetine (REB) in tablets. The method is based on derivatization with 7-chloro-4-nitrobenzofurazan. The product showed an absorption maximum at 476 nm and a fluorescence emission peak at 533 nm in ethyl acetate. The optimum conditions of the reaction were investigated, and it was found that the reaction proceeded quantitatively at pH 8.5, 70C in 5 min. The calibration graph is rectilinear over the range of 0.02-0.40 μg/mL. The relative standard deviation values for intraday and interday precision were 0.40-0.93 and 0.54-1.37%, respectively. The proposed method was applied to the assay of REB in tablets. Mean recovery of REB from the tablets ranged between 99.91-100.20%. The results were compared statistically with those obtained by a method reported in the literature. The method is sensitive, simple, and selective, and can be used for routine quality control analysis.

A method of high sensitivity and in situ determination of trace cobalt(II) in water samples with salicyl fluorone

2014 ◽  
Vol 70 (7) ◽  
pp. 1182-1187 ◽  
Author(s):  
Zhe Chen ◽  
Hua Li
Keyword(s):  
Flow Injection ◽  
Water Samples ◽  
High Sensitivity ◽  
Basic Solution ◽  
Optimum Conditions ◽  
Cetylpyridinium Bromide ◽  
Test Conditions ◽  
Relative Standard

Based on the sensitive reaction of Co(II) and salicyl fluorone with the presence of cetylpyridinium bromide in basic solution, a new method of flow injection micelle-solubilized spectrophotometry was developed for the determination of cobalt. The reaction was monitored for the absorbance of Co(II) at 540 nm. The reagents, flow injection variables and effects of foreign ions were investigated and the optimum conditions were established. At the optimum test conditions, the developed method provides a linearity range of 3–40 μg L−1 with a detection limit of 0.1 μg L−1 at about 60 h−1 sampling frequency. Relative standard deviation of 0.91, 0.95 and 0.89% were obtained for the determination of 3, 15 and 30 μg L−1 Co(II) solution. The proposed method has been successfully applied for analysis of trace amounts of cobalt in water samples.

On the spectrophotometric determination of with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol

1988 ◽  
Vol 66 (3) ◽  
pp. 401-405 ◽  
Author(s):  
Lumír Sommer ◽  
Eva Šamlotová
Keyword(s):  
Spectrophotometric Determination ◽  
Natural Water ◽  
Water Samples ◽  
Sodium Sulphate ◽  
Optimum Conditions ◽  
Reaction Conditions ◽  
Masking Agents ◽  
Triton X ◽  
Sulphosalicylic Acid

2-(5-Bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) is a suitable reagent for the spectrophotometric determination of uranium but results are easily influenced by the reaction conditions as well as various common ions and masking agents. Optimum conditions, which must be carefully maintained, are 30% (v/v) dimethylformamide, 0.1% triton X-100, ≥ 8 × 10−5 M 5-Br-PADAP, 8 × 10−2 M triethanolamine, 7 × 10−3 M sodium fluoride, 10−2 M 5-sulphosalicylic acid, and 579 nm. Sodium sulphate (10−2 M) and CDTA (5.7 × 10−3 M) may serve as additional masking agents. A previous separation of uranium by extraction with 0.1 M tri-n-octylamine in benzene from 4 M HCl and re-extraction of 0.3 M HCl is recommended for analysis of natural water samples.

scholarly journals Aqueous Two-Phase Systems: A New Approach for the Determination of Brilliant Blue FCF in Water and Food Samples

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Sabah Shiri ◽  
Tahere Khezeli ◽  
Shahram Lotfi ◽  
Sina Shiri
Keyword(s):  
Polyethylene Glycol ◽  
Standard Deviation ◽  
Food Samples ◽  
Brilliant Blue ◽  
Phase System ◽  
Optimum Conditions ◽  
Two Phase ◽  
Brilliant Blue Fcf ◽  
Relative Standard

A novel, simple, and more sensitive spectrophotometric procedure has been developed for the determination of brilliant blue FCF in water and food samples by an aqueous two-phase system (ATPS). In this method, adequate amount of polyethylene glycol/ sodium carbonate (PEG-4000/Na2CO3) was added to aqueous solution for formation of a homogeneous solution. To the mixture solution, suitable amount ofNa2CO3was added, the mixture solution was shaken until the salt was dissolved, and then it was separated into two clear phases easily and rapidly. The target analyte in the water sample was extracted into the polyethylene glycol phase. After extraction, measuring the absorbance at 634 nm was done. The effects of different parameters such as polyethylene glycol (type and concentration), pH, salt (type and amount), centrifuge time, and temperature on the ATPS of dye was investigated and optimum conditions were established. Linear calibration curves were obtained in the range of 0.25–750 ng/mL for brilliant blue FCF under optimum conditions. Detection limit based on three times the standard deviation of the blank (3Sb) was 0.12 ng/mL. The relative standard deviation (RSD) for 400 ng/mL was 3.14%. The method was successfully applied to the determination of brilliant blue FCF in spiked samples with satisfactory results. The relative recovery was between 96.0 and 102.2%.

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