A Portable Spark-Induced Breakdown Spectroscopic (SIBS) Instrument and its Analytical Performance

2019 ◽  
Vol 73 (6) ◽  
pp. 698-708 ◽  
Author(s):  
Iyll-Joon Doh ◽  
Carmen Gondhalekar ◽  
Valery Patsekin ◽  
Bartek Rajwa ◽  
Keegan Hernandez ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Coefficient Of Variation ◽  
Signal Intensity ◽  
Quantitative Measurement ◽  
Silicon Wafers ◽  
Tungsten Electrodes ◽  
Nist Database ◽  
Spectral Peaks ◽  
Particulate Silica ◽  
Delay Generator

A compact spark-induced plasma spectroscopic device was developed to detect elements used in a variety of applications. The system consists of a spark generator connected to tungsten electrodes, a custom-built delay generator, and two spectrometers that together cover the ultraviolet visible (UV–Vis) range (214–631 nm). The system was evaluated by qualitatively and quantitatively sampling copper standards. Prominent spectral peaks were identified using the NIST database for atomic emissions. The effectiveness of the proposed system was also tested with a lanthanide sample (gadolinium) and provided qualitative identification of the characteristic peaks. A semi-quantitative measurement for silicon and gold was performed using variable amounts of each particulate. Silica microbeads in solution were applied to paper wafers, while gold nanoparticles were sputter-coated onto silicon wafers. Results showed a positive correlation between the intensity of the signal and the concentration of each type of particulate. The variation of signal intensity was investigated to determine the repeatability, and the coefficient of variation was lowered from 60% to 25% after averaging measurements of multiple ablations per observation.

Contrast magnetic resonance imaging for measurement of cartilage glycosaminoglycan content in dogs: A pilot study

2013 ◽  
Vol 26 (02) ◽  
pp. 100-104 ◽  
Author(s):  
M. C. Stewart ◽  
L. Ciobanu ◽  
P. D. Constable ◽  
J. F. Naughton
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Coefficient Of Variation ◽  
Signal Intensity ◽  
Linear Regression Analysis ◽  
Resonance Imaging ◽  
Post Contrast ◽  
Enhanced Mri ◽  
Over Time

SummaryObjective: To assess the ability of a contrast-enhanced magnetic resonance imaging (MRI) technique to quantitatively determine glycosaminoglycan content in canine articular cartilage.Methods: Fifty-four full-thickness cartilage discs were collected from the femorotibial and scapulohumeral joints of three adult dogs immediately following euthanasia. One set of discs from each dog was analysed for glycosaminoglycan content using a colourimetric laboratory assay. The remaining position-matched set of discs from contralateral limbs underwent pre- and post-contrast gadolinium-enhanced MRI, using repeated saturation recovery pulse sequences which were used to generate calculated T1 maps of the cartilage discs. Linear regression analysis was then performed relating delayed gadolinium-enhanced MRI T1 calculated signal intensity to the cartilage glycosaminoglycan content normalized to DNA content. Repeatability of triplicate measurements was estimated by calculating the coefficient of variation.Results: Mean coefficient of variation estimates for the gadolinium-enhanced MRI T1 signal intensity values for nine sampling sites from three dogs ranged from 5.9% to 7.5%. Gadolinium-enhanced MRI T1 signal intensity was significantly correlated (p <0.05) with normalized glycosaminoglycan content in two dogs (r = 0.79, p = 0.011; r = 0.78, p = 0.048), but not in the third dog (r = 0.53, p = 0.071).Clinical significance: Gadolinium-enhanced MRI assessment of cartilage may be predictive of glycosaminoglycan content and therefore offer an in vivo assessment of changes in cartilage characteristics over time. Additional studies appear indicated to determine the reliability and clinical applicability of gadolinium-enhanced MRI in detecting changes in cartilage over time.

DNA-mediated site-specific deposition of gold nanoparticles on silicon wafers

Nanoscale ◽  
2010 ◽  
Vol 2 (12) ◽  
pp. 2579 ◽  
Author(s):  
Katharina J. C. Heimann ◽  
Clemens Richert
Keyword(s):  
Gold Nanoparticles ◽  
Silicon Wafers ◽  
Site Specific

Gas-Liquid Chromatography of Bolstar Formulations

1979 ◽  
Vol 62 (4) ◽  
pp. 742-745
Author(s):  
Willard G Boyd
Keyword(s):  
Coefficient Of Variation ◽  
Quantitative Measurement ◽  
Internal Standard ◽  
Gas Liquid Chromatography ◽  
Flame Ionization Detection ◽  
Good Precision ◽  
Synthetic Sample ◽  
Flame Ionization ◽  
Average Coefficient ◽  
Technical Material

Abstract A simple and rapid gas-liquiJ chromatographic method for assaying Bolstar formulations is described. Flame ionization detection, a column packed with SE-30/OV-210 on Gas-Chrom Q, and on-column injection are specified. Tetracosane internal standard in benzene is added to the weighed sample, and integratorarea ratios are used for quantitative measurement. The integrator response ratio of Bolstar area to tetracosane internal standard area, plotted against Bolstar concentration, is linear over a 2.85–7.78 mg/mL range. A technical material, a synthetic formulation, and 4 commercial formulations of Bolstar were assayed with good precision. Three assays of technical material against 3 standard weighings gave a coefficient of variation of 0.479%. Eight assays of a synthetic sample formulation, containing 63.86 theoretical per cent Bolstar, yield an average of 63.81% Bolstar with a coefficient of variation of 0.213%. Two assays each of 4 commercial Bolstar formulations gave an average coefficient of variation of 0.280%. Statistical analysis of 12 integrator response ratios, standard area to internal standard area, for 1 set of analyses gave a coefficient of variation of 0.322%.

Plasma glucose measurement with the Yellow Springs Glucose Analyzer.

1978 ◽  
Vol 24 (1) ◽  
pp. 150-152 ◽  
Author(s):  
K S Chua ◽  
I K Tan
Keyword(s):  
Hydrogen Peroxide ◽  
Glucose Oxidase ◽  
Plasma Glucose ◽  
Coefficient Of Variation ◽  
Glucose Concentration ◽  
Quantitative Measurement ◽  
Reaction Chamber ◽  
Glucose Measurement ◽  
Immobilized Glucose Oxidase ◽  
Carry Over

Abstract The Yellow Springs Glucose Analyzer, a device for the quantitative measurement of glucose concentrations, involves the use of immobilized glucose oxidase, incorporated on a membrane covering a hydrogen peroxide sensor. Operation of the instrument is simple. After an initial calibration, 25 microliter of plasma is injected into a reaction chamber. At 45 s a digital result for glucose is displayed. The within-batch coefficient of variation for the method is 1.2% or less for glucose concentrations of 0.94 to 3.98 g/liter. The between-batch coefficient of variation is 5.8% or less for glucose concentrations of 0.29 to 2.91 g/liter. Concentration and readout are linearly related to at least 4.6 g/liter. Analytical recoveries ranged from 100 to 102%. Carry-over was negligible. Values for glucose concentration obtained with the instrument compared well (r = 0.997) with those obtained with the Beckman Glucose Analyzer.

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