Calibration curve

About: Calibration curve is a research topic. Over the lifetime, 6552 publications have been published within this topic receiving 95128 citations.

One-step facile synthesis of SnO2@Nd2O3 nanocomposites for selective amidol detection in aqueous phase

Abstract: In this approach, amidol, a toxic organic chemical, is used as a staining developer electrochemically detected by using binary SnO2@Nd2O3 nanocomposites (NCs) by deposition onto a flat glassy carbon electrode (GCE). The NCs were prepared by a wet-chemical process followed by characterization with various conventional techniques, such as the UV-Vis, FTIR, XRD, FESEM, EDS and XPS techniques. During the electrochemical method, the main key points are the sensor analytical parameters, such as selectivity, sensitivity, linearity, concentration variations, validity, response time, and repeatability. The calibration curve was plotted in the full concentration range (FCR) from 0.1 mM to 0.1 nM. From the FCR, the linear dynamic range (LDR) was found in the range 1.0 mM to 0.1 nM. The sensitivity is calculated from the slope of the calibration plot in LDR, which was 158.228 μA μM−1 cm−2. The limit of detection (LOD) and limit of quantification (LOQ) of the fabricated chemical sensor were 0.06 nM and 0.2 nM. respectively. The binary doped NC-based chemical sensor probe is cheap, efficient, and environmentally friendly for detecting unsafe chemicals in the environmental and healthcare fields on a broad scale.

Improving provenance studies in migratory birds when using feather hydrogen stable isotopes

Abstract: Hydrogen stable isotopes (δ2H) in feathers are used to determine the origin and migration strategy of birds. To identify the geographic location of the site of feather synthesis, calibration curves for the relation between feather δ2H and amount-weighted growing-season δ2H in precipitation are used to generate feather δ2H isoscapes. Factors like species, age and year might generate isotopic variation in calibration curves, but the extent to which accounting for variation may improve calibration curves and hence provenance determination of birds, is unknown. We compared three European calibration curves: 1) an existing multi-species curve, uncorrected for age and year variation, and two species-specific calibration curves, based on mallard Anas platyrhynchos feathers, of 2) varying age and year, and 3) juvenile natal origin, corrected for year variation. Calibration curves using ordinary least square linear regression (OLS) as opposed to standard major axis regression showed least bias in estimation. As expected, we found that a single species (mallard) OLS calibration curve corrected for age and year yielded the highest coefficient of determination, but was still surprisingly similar to the other two calibration curves. Nevertheless, when using feathers of known-origin to assess provenance accuracy, the calibration curve that accounted for species, age and year variation yielded the best prediction in as many as 59% of the cases. Our study is the first to demonstrate implications of isotopic variation on assessing the origin of individual birds, but also highlights the relatively small gain in precision that is achieved by generating species, age and year specific calibration curves rather than resorting to more general alternatives.

Immunological assay method

Abstract: An immunological assay method, wherein the concentration of a substance to be assayed is calculated from a calibration curve, which is formed in the preparation of a reagent or in the assay of a sample based on parameter(s) determined in the preparation of the reagent, without the need of forming any additional calibration curve each time, is disclosed. By the immunological assay method of the present invention, the concentration of the substance to be assayed can be efficiently and discontinuously determined, when compared with conventional ones. The method of the present invention is particularly suitable for quantitatively determining an antigen or an antibody.

The Instrument Spreading Correction in GPC. I. The General Shape Function Using a Linear Calibration Curve

Abstract: A general shape function is proposed for describing the instrumental spreading behavior in gel permeation chromatography (GPC) columns due to axial dispersion and skewing effects. The general shape function contains statistical coefficients which describe the axial dispersion, skewing, and flattening of ideal monodisperse standards. A method denoted as the “method of molecular weight averages” is used to derive equations to correct GPC number- and weight-average molecular weights and intrinsic viscosities calculated from linear molecular weight calibration curves. The validity of these equations is experimentally verified with data for polystyrene, polybutadiene, and polyvinyl chloride polymers in tetrahydrofuran. The physical significance of the correction equations and their statistical coefficients is discussed in relation to the observed GPC chromatograms. Application of this shape function to the numerical Fourier analysis method for correcting differential molecular weight distribution (DMW...