Search results
Results from the WOW.Com Content Network
A calibration curve plot showing limit of detection (LOD), limit of quantification (LOQ), dynamic range, and limit of linearity (LOL).. In analytical chemistry, a calibration curve, also known as a standard curve, is a general method for determining the concentration of a substance in an unknown sample by comparing the unknown to a set of standard samples of known concentration. [1]
[3] [4] The most common approach for accounting for matrix effects is to build a calibration curve using standard samples with known analyte concentration and which try to approximate the matrix of the sample as much as possible. [2] This is especially important for solid samples where there is a strong matrix influence. [5]
A calibration curve is obtained by measuring a series of standard solutions with known concentrations, which can be used to determine the concentration of an unknown sample using linear regression analysis. [10] For example, by comparing the absorbance values of a solution with an unknown concentration to a series of standard solutions with ...
The instrument detection limit (IDL) is the analyte concentration that is required to produce a signal greater than three times the standard deviation of the noise level. This may be practically measured by analyzing 8 or more standards at the estimated IDL then calculating the standard deviation from the measured concentrations of those standards.
The calibration curve that does not use the internal standard method ignores the uncertainty between measurements. The coefficient of determination (R 2 ) for this plot is 0.9985. In the calibration curve that uses the internal standard, the y-axis is the ratio of the nickel signal to the yttrium signal.
In comparison to the calibration curve method, the standard addition method has the advantage of the matrices of the unknown and standards being nearly identical. [1] This minimizes the potential bias arising from the matrix effect when determining the concentration.
This standard curve is then used to determine the concentration of the unknown protein. The following elaborates on how one goes from the standard curve to the concentration of the unknown. First, add a line of best fit, or Linear regression and display the equation on the chart.
Detector response of calibration standard (either aqueous or in another suitable solvent) - This gives the best case scenario for detector response, i.e. under conditions of zero ion suppression Pre-prepared sample matrix spiked with an identical concentration of analyte - This demonstrates the effect of ion suppression