A Rapid Method of Determining Ammonium in Water With a Univalent Cation Glass Electrode

1971 ◽  
Vol 28 (5) ◽  
pp. 759-764 ◽  
Author(s):  
Jan Barica
Keyword(s):  
Rapid Method ◽  
Direct Determination ◽  
Glass Electrode ◽  
Ammonium Ion ◽  
Mean Error ◽  
Univalent Cation ◽  
The Mean

The use of a univalent cation glass electrode for determining ammonium in water is described. The method enables direct determination of ammonium ion in concentrations above 0.5 mg/liter without any dilution or pretreatment of sample. A constant background of Na+ and K+ in samples is required, with concentration of potassium being lower than that of ammonium. For several types of natural and enriched waters with ammonium content up to 40 mg/liter NH4-N, the mean error by the method was ±4.9%.

A rapid method for the direct determination of zinc in brass or bronze

The Analyst ◽  
1941 ◽  
Vol 66 (785) ◽  
pp. 321
Author(s):  
W. Hoffman ◽  
G. B. Thackray
Keyword(s):  
Rapid Method ◽  
Direct Determination

A Simple Rapid Method for Direct Determination of Total Fatty Matter in Soaps

1977 ◽  
Vol 79 (7) ◽  
pp. 285-288 ◽  
Author(s):  
M. K. Kundu ◽  
A. T. Deb ◽  
S. P. Gupta
Keyword(s):  
Rapid Method ◽  
Direct Determination ◽  
Fatty Matter ◽  
Total Fatty Matter

Determination of Lead in Bonemeal by Differential Pulse Anodic Stripping Voltammetry Using a Hydrochloric Acid Solubilization

1983 ◽  
Vol 66 (4) ◽  
pp. 985-988
Author(s):  
R Duane Satzger ◽  
Roy W Kuennen ◽  
Fred L Fricke
Keyword(s):  
Hydrochloric Acid ◽  
Rapid Method ◽  
Perchloric Acid ◽  
Anodic Stripping Voltammetry ◽  
Stripping Voltammetry ◽  
Differential Pulse ◽  
Anodic Stripping ◽  
The Mean

Abstract A safe, rapid method is described for the determination of lead in bonemeal. This method uses a hydrochloric acid solubilization performed under pressure followed by determination by differential pulse anodic stripping voltammetry. This provides an alternative to a nitric-perchloric acid wet ash. Data obtained using both methods are compared. The mean recovery of a standard Pb spike was 99.2 ± 1%. The concentration of Pb in bonemeal ranged from 1.0 to 15.6 μg/g.

scholarly journals Application of ion pair complexes to design novel potentiometric membrane sensors for direct determination of frusemide in pharmaceuticals

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Nagaraju Rajendraprasad ◽  
Kanakapura Basavaiah
Keyword(s):  
Limit Of Detection ◽  
Direct Determination ◽  
Standard Addition ◽  
Ion Pair ◽  
Bromocresol Green ◽  
Bromophenol Blue ◽  
Experimental Parameters ◽  
The Mean

Abstract Background Fabrication of two membrane sensors using two acidic indicators among sulphonthalein dyes, namely bromophenol blue (BPB) and bromocresol green (BCG), and their use as indicative electrodes for the quantification of frusemide (FUR) is presented. The ion pair complexes of FUR with BPB or BCG are used to prepare the membranes in THF solvent, PVC matrix and dibutyl phthalate (DBP) as plasticizer and subsequently to fabricate FUR-BPB (Sensor I) and FUR-BCG (Sensor II) sensors. Results Sensors I and II are employable to determine 2.4 × 10-5–2.4 × 10-3 mol/L FUR at operative pH of 3.71. The calibration curve between the potentials against the concentration of FUR yielded the slopes of 58.73 ± 1 and 57.66 ± 1 mV/decade, respectively, using Sensors I and II, and this confirmed the Nernstian behaviour. Satisfactory correlation was obtained between the measured potentials and FUR concentration with the proposed sensors, and this was revealed by regression coefficient values of 0.9987 and 0.9980 for Sensors I and II, respectively. The LOD (limit of detection) values were calculated and reported for both the sensors. The experimental parameters were optimised to yield acceptable characteristics of both the sensors in the context of performance. The role of excipients of tablets and interferences were assessed by standard addition protocol. The obtained results confirmed the ineffective role of excipients of tablets and foreign species used as interferents. Conclusion The designed sensors were validated to confirm the accurate, precise, robust and rugged functioning in determining FUR. The mean of recovered FUR, close to 100%, revealed the acceptable and effective functioning of the proposed sensors. Excellent results were obtained by FUR tablets’ analysis using both the sensors.

scholarly journals Characteristic Times for the Fermi–Ulam Model

2021 ◽  
Vol 31 (02) ◽  
pp. 2130004
Author(s):  
Joelson D. Veloso Hermes ◽  
Edson D. Leonel
Keyword(s):  
Fractal Dimension ◽  
Phase Space ◽  
Lyapunov Exponent ◽  
Direct Determination ◽  
Recurrence Time ◽  
Invariant Curves ◽  
Lyapunov Time ◽  
Normal Diffusion ◽  
The Mean

The mean Poincaré recurrence time as well as the Lyapunov time are measured for the Fermi–Ulam model. It is confirmed that the mean recurrence time is dependent on the size of the window chosen in the phase space where particles are allowed to return. The fractal dimension of the region is determined by the slope of the recurrence time against the size of the window and two numerical values are measured: (i) [Formula: see text] confirming normal diffusion for chaotic regions far from periodic domains and (ii) [Formula: see text] leading to anomalous diffusion measured inside islands of stability and invariant curves corresponding to regular orbits, a signature of local trapping of an ensemble of particles. The Lyapunov time is the inverse of the Lyapunov exponent. Therefore, the Lyapunov time is measured over different domains in the phase space through a direct determination of the Lyapunov exponent.

scholarly journals A symmetrical method to obtain shear moduli from microrheology

Soft Matter ◽  
2018 ◽  
Vol 14 (19) ◽  
pp. 3716-3723 ◽  
Author(s):  
Kengo Nishi ◽  
Maria L. Kilfoil ◽  
Christoph F. Schmidt ◽  
F. C. MacKintosh
Keyword(s):  
Elastic Moduli ◽  
Direct Determination ◽  
Analysis Method ◽  
Shear Moduli ◽  
Mean Squared Displacement ◽  
The Mean ◽  
Symmetrical Method ◽  
Probe Particles

Passive microrheology deduces shear elastic moduli from thermally fluctuating motion of probe particles. We introduce and test an analysis method for direct determination of these moduli from the mean-squared displacement of a probe.

A Novel Method For The Direct Determination Of Platelet-Associated IgG (PAIgG) Employing Rocket Immunoelectrophoresis (Laurell)

1981 ◽  
Author(s):  
T J Kunicki ◽  
S M Kristopeit ◽  
R H Aster
Keyword(s):  
Direct Determination ◽  
Human Platelets ◽  
Rabbit Antibody ◽  
Human Igg ◽  
Novel Method ◽  
The Mean ◽  
Triton X ◽  
Phosphate Buffered Saline ◽  
Indirect Assay

The diagnosis and management of immune thrombocytopenia requires an effective method for the quantitation of platelet- associated IgG (PAIgG). Although several methods have been recently devised for this purpose, the search continues for a method which will prove to be accurate and reproducible, and yet simple enough to be utilized by the general clinical hemostasis laboratory. We now describe the development of an assay for PAIgG which we believe satisfies these criteria.Human platelets were isolated by differential centrifugation, washed five times in Tris-HCl pH 7.4 or phosphate buffered saline pH 7.4, both containing 5mM EDTA, and disrupted in 0.1M sodium acetate buffer pH 5.0 containing 1% (v/v) Triton X-100. Rabbit antibody specific for γ chains of human IgG (purified IgG fraction from DAKO) was carbamylated such that its isoelectric point was decreased to roughly 5.0. Total PAIgG was measured by electrophoresis at pH 5.0 of Triton X-100 disrupted washed platelets against the carbamylated rabbit anti-human IgG (γ) in 1% agarose gels containing 0.5% Triton X-100.The mean total PAIgG for 8 normals, was 5.7 fg/platelet (range 4.9 to 7.0). This technique is applicable to the quantitation of alloantibodies bound to normal platelets (indirect assay) as well as the quantitation of PAIgG on platelets of individuals with immune thrombocytopenic states, such as ITP.

Metallic rough surface retrieval from the specular intensity of scattered optical waves

2000 ◽  
Vol 78 (11) ◽  
pp. 1023-1033
Author(s):  
Z D Genchev ◽  
H Y Stoyanov
Keyword(s):  
Rough Surface ◽  
Direct Determination ◽  
Single Scattering ◽  
Metallic Surface ◽  
Optical Intensity ◽  
Statistical Parameters ◽  
Optical Waves ◽  
The Mean ◽  
Analytical Expressions

We present a solution to the direct determination of the statistical parameters (root mean square deviation and correlation length), characterizing the profile of a random rough metallic surface with small slopes and heights, thus producing single scattering as well as a slight multiple scattering. This is done from the specular, coherent, component of the mean intensity of the optical waves scattered from the surface. In the frame of second-order perturbation theory, analytical expressions are derived for the specular component of the scattered radiation, and a retrieval of the rough surface parameters from the measured optical intensity is described. PACS Nos.: 02.25Fx, 03.40Kf, 41.20jb, 84.40

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