Advances in the Preconcentration of Dissolved Ions in Water Samples

1976 ◽  
Vol 20 ◽  
pp. 437-443
Author(s):  
D. E. Leyden
Keyword(s):  
Water Samples ◽  
Limit Of Detection ◽  
Fluorescence Analysis ◽  
X Ray ◽  
Accuracy And Precision ◽  
Dissolved Ions ◽  
Trace Elements In Water ◽  
Ideal Method ◽  
The Ideal

X-ray fluorescence is well established as an analytical method for the determination of multi-element systems. It is a technique which provides high accuracy and precision. However, it has serious limitations in the lower limit of detection for elemental analysis in environmental samples. In order to overcome this limitation some method of preconcentration or enrichment of the trace elements in water samples must be provided. In recent years many techniques have been developed for this purpose. Some of these techniques involve simple chemical or physical manipulations of the sample. In all cases, the technique should be rapid, simple, and not contaminate the sample. Because it is more convenient to use solid samples for X-ray fluorescence analysis, the ideal method of preconcentration results in a solid sample.

Determination of Trace Elements in Plant Material by Fluorescent X-Ray Analysis

1961 ◽  
Vol 5 ◽  
pp. 433-446
Author(s):  
F.W. Lytle ◽  
W.B. Dye ◽  
H. J. Seim
Keyword(s):  
Trace Elements ◽  
Exchange Resin ◽  
Limit Of Detection ◽  
Plant Materials ◽  
X Ray ◽  
Group I ◽  
Accuracy And Precision ◽  
Wet Ashing ◽  
Exchange Membrane

AbstractA method is presented for the determination of trace elements in plant materials. The samples were composed of organic material, which was eliminated by wet ashing, large amounts of group I and II elements, and many trace elements of interest in the concentration range 0.1–100 ppm. An attempt to achieve preconcentration of the trace elements by absorption on cation-exchange membrane (which could have been used directly for analysis) was unsuccessful because of preferential absorption and saturation of the membrane by group I and II cations. Formation of complex-metal anions in acid solution and absorption on anion-exchange resin was more successful, but, because of a lack of precision and incomplete absorption, the technique was inadequate. In the most successful preconcentration scheme, an organo-metallic precipitation was used in a matrix suitable for X-ray analysis. In this precipitate the elements Fe, Mn, Cu, Zn, Co, Mo, Cr, Ni, Ti, V, Ca, Sn, Sc, Ba, and Pb could be quantitatively determined. In many cases the lower limit of detection was 0.01 ppm. The accuracy and precision of the technique were proved by comparison to chemically analyzed samples, recovery experiments, and replicate analyses. The method is generally applicable for the analysis of many organic materials.

Some Observations on the Use of Certain Analyzing Crystals for the Determination of Silicon and Aluminum*

1965 ◽  
Vol 9 ◽  
pp. 515-527 ◽  
Author(s):  
Frank L. Chan
Keyword(s):  
Count Rate ◽  
Limit Of Detection ◽  
Fluorescence Analysis ◽  
Organic Crystals ◽  
Background Count ◽  
X Ray ◽  
Pure Silicon ◽  
Order Of Magnitude ◽  
Constant Potential

AbstractDuring the past several years, a number of analyzing crystals have been prepared in the U.S. Air Force Aerospace Research Laboratories. Crystals such as alkaline acid malonates, sucrose, pentaerythritol (PET), and several others have been grown with the sole purpose of application in X-ray fluorescence analysis of silicon, aluminum, and other elements of low atomic number. Crystals from natural sources, such as quartz, mica, and gypsum, have also been procured from different parts of the world for this purpose.Among the analyzing crystals so prepared, pentaerythritol gave the highest count rate for silicon and aluminum. However, since this crystal is organic in nature, great care must be exercised in handling this type of crystal in order to obtain constant count rates. For the analysis of silicon and aluminum, a-quartz crystal gave a somewhat low count rate, but this crystal has certain advantages over the organic crystals, and can be used for analysis of materials having high silicon and aluminum content.For instance, when using a conventional X-ray emission vacuum spectrograph of standard make, with the latest alterations, one of the PET crystals attained a count rate of 101,870 cps for pure silicon when the instrument was operated at 60 kVP and SO m A with a negligible background count. With a constant potential attachment and operated at 60 kVP and 34 mA, 1.15,600 cps with negligible background count was obtained for silicon. The count rate for aluminum was of the same order of magnitude with somewhat higher background count.Several sets of standards have been procured and small amounts of silicon and aluminum in these standards have been analyzed by the latest modified vacuum spectrograph. These results are under study and the limit of detection calculated. Procedures and results are described and discussed.

scholarly journals Highly sensitive determination of heavy metals in water prior to and after remediation using Citrofortunella Microcarpa

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shirley T. Palisoc ◽  
Remuel Isaac M. Vitto ◽  
Marissa G. Noel ◽  
Katja T. Palisoc ◽  
Michelle T. Natividad
Keyword(s):  
Water Samples ◽  
Limit Of Detection ◽  
Current Response ◽  
Experimental Conditions ◽  
X Ray ◽  
Highly Sensitive ◽  
Novel Method ◽  
Sensitive Determination ◽  
Strong Linear Relationship

AbstractA highly sensitive bismuth/silver nanoparticles/Nafion-modified screen-printed graphene electrode was fabricated and was utilized for the detection of trace lead (Pb) concentrations in river water samples prior to and after remediation using calamansi (Citrofortunella Microcarpa) rinds in different forms viz., ground sun-dried, dry-ashed, food-grade pectin, fractionated pectin, and alcohol insoluble solids—extracted pectin. All these forms of pectin remediated Pb in the water samples. Hence, this novel method of using calamansi rinds in different forms is an effective method for the removal of lead in water. The electrode was characterized using scanning electron microscopy and energy dispersive x-ray spectrometry which confirmed the presence of the modifiers on the electrode surface. The limit of detection of 267.6 ppt and the strong linear relationship between the Pb concentration and the anodic current response (R2 = 0.999) were obtained under optimized experimental conditions and parameters.

X-Ray Analysis of Frozen Hydrated Sections:The Unconventional Approach

1982 ◽  
Vol 40 ◽  
pp. 754-757
Author(s):  
R. Beeuwkes ◽  
A. Saubermann ◽  
P. Echlin ◽  
S. Churchill
Keyword(s):  
Ratio Method ◽  
Frozen Sections ◽  
Technical Problems ◽  
Sample Handling ◽  
X Ray ◽  
Common Group ◽  
Ideal Method ◽  
Classic Paper ◽  
Physical Principles ◽  
The Ideal

Fifteen years ago, Hall described clearly the advantages of the thin section approach to biological x-ray microanalysis, and described clearly the ratio method for quantitive analysis in such preparations. In this now classic paper, he also made it clear that the ideal method of sample preparation would involve only freezing and sectioning at low temperature. Subsequently, Hall and his coworkers, as well as others, have applied themselves to the task of direct x-ray microanalysis of frozen sections. To achieve this goal, different methodological approachs have been developed as different groups sought solutions to a common group of technical problems. This report describes some of these problems and indicates the specific approaches and procedures developed by our group in order to overcome them. We acknowledge that the techniques evolved by our group are quite different from earlier approaches to cryomicrotomy and sample handling, hence the title of our paper. However, such departures from tradition have been based upon our attempt to apply basic physical principles to the processes involved. We feel we have demonstrated that such a break with tradition has valuable consequences.

Sorption of Se (IV) from aqueous solutions with subsequent determination by X-ray fluorescence analysis

2020 ◽  
Vol 86 (10) ◽  
pp. 5-9
Author(s):  
D. G. Filatova ◽  
A. A. Arkhipenko ◽  
M. A. Statkus ◽  
V. V. Es’kina ◽  
V. B. Baranovskaya ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Fluorescence Analysis ◽  
Standard Samples ◽  
Phase Contact Time ◽  
Sorbent Phase ◽  
X Ray ◽  
Fundamental Parameters ◽  
Inductively Coupled ◽  
Subsequent Determination

An approach to sorptive separation of Se (IV) from solutions on a novel S,N-containing sorbent with subsequent determination of the analyte in the sorbent phase by micro-x-ray fluorescence method is presented. The sorbent copolymethylenesulfide-N-alkyl-methylenamine (CMA) was synthesized using «snake in the cage» procedure and proven to be stable in acid solutions. Conditions for quantitative extraction of Se (IV) were determined: sorption in 5 M HCl or 0.05 M HNO3 solutions when heated to 60°C, phase contact time being 1 h. The residual selenium content in the solution was determined by inductively coupled plasma mass spectrometry (ICP-MS) using 82Se isotope. The absence of selenium losses is proved and the mechanism of sorption interaction under specified conditions is proposed. The method of micro-x-ray fluorescence analysis (micro-RFA) with mapping revealed a uniform distribution of selenium on the sorbent surface. The possibility of determining selenium in the sorbent phase by micro-RFA is shown. When comparing the obtained results with the results of calculations by the method of fundamental parameters, it is shown the necessity of using standard samples of sorbates to obtain correct results of RFA determination of selenium in the sorbent phase.

Determination of the composition of binary chalcogenide glasses by X-ray fluorescence analysis

2010 ◽  
Vol 44 (1) ◽  
pp. 24-27 ◽  
Author(s):  
G. A. Bordovsky ◽  
A. V. Marchenko ◽  
P. P. Seregin ◽  
N. N. Smirnova ◽  
E. I. Terukov
Keyword(s):  
Chalcogenide Glasses ◽  
Fluorescence Analysis ◽  
X Ray

scholarly journals Determination of cobalt in water samples by atomic absorption spectrometry after pre-concentration with a simple ionic liquid-based dispersive liquid-liquid micro-extraction methodology

2010 ◽  
Vol 8 (3) ◽  
pp. 617-625 ◽  
Author(s):  
Hossein Abdolmohammad-Zadeh ◽  
Elnaz Ebrahimzadeh
Keyword(s):  
Ionic Liquid ◽  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Water Samples ◽  
Limit Of Detection ◽  
Absorption Spectrometry ◽  
Experimental Conditions ◽  
Flame Atomic Absorption ◽  
Relative Standard

AbstractA rapid dispersive liquid-liquid micro-extraction (DLLME) methodology based on the application of 1-hexylpyridinium hexafluorophosphate [C6py][PF6] ionic liquid (IL) as an extractant solvent was applied for the pre-concentration of trace levels of cobalt prior to determination by flame atomic absorption spectrometry (FAAS). 1-Phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) was employed as a chelator forming a Co-PMBP complex to extract cobalt ions from aqueous solution into the fine droplets of [C6py][PF6]. Some effective factors that influence the micro-extraction efficiency include the pH, the PMBP concentration, the amount of ionic liquid, the ionic strength, the temperature and the centrifugation time which were investigated and optimized. In the optimum experimental conditions, the limit of detection (3s) and the enrichment factor were 0.70 µg L−1 and 60, respectively. The relative standard deviation (RSD) for six replicate determinations of 50 µg L−1 Co was 2.36%. The calibration graph using the pre-concentration system was linear at levels 2–166 µg L−1 with a correlation coefficient of 0.9982. The applicability of the proposed method was evaluated by the determination of trace amounts of cobalt in several water samples.

scholarly journals Development and Validation of a Rapid RP-HPLC Method for the Estimation of Esmolol Hydrochloride in Bulk and Pharmaceutical Dosage Forms

2010 ◽  
Vol 7 (3) ◽  
pp. 807-812 ◽  
Author(s):  
Vanita Somasekhar ◽  
D. Gowri Sankar
Keyword(s):  
Limit Of Detection ◽  
Hplc Method ◽  
Detector Response ◽  
Reverse Phase Hplc ◽  
Limit Of Quantification ◽  
Pharmaceutical Dosage Forms ◽  
Rp Hplc ◽  
Accuracy And Precision ◽  
Development And Validation

A reverse phase HPLC method is described for the determination of esmolol hydrochloride in bulk and injections. Chromatography was carried on a C18column using a mixture of acetonitrile, 0.05 M sodium acetate buffer and glacial acetic acid (35:65:3 v/v/v) as the mobile phase at a flow rate of 1 mL/min with detection at 275 nm. The retention time of the drug was 4.76 min. The detector response was linear in the concentration of 1-50 μg/mL. The limit of detection and limit of quantification was 0.614 and 1.86 μg/mL respectively. The method was validated by determining its sensitivity, linearity, accuracy and precision. The proposed method is simple, economical, fast, accurate and precise and hence can be applied for routine quality control of esmolol hydrochloride in bulk and injections.

Sign in / Sign up

Export Citation Format

Share Document