previous validated work has a calibration curve and linear regression equation and the work was done by another researcher and i need using this validated method in a new work. I prepared low medium and high QC and got linear regression equation and my equation has given the same concentration if i used equation in previous work which has been done by other.
the question can i used this equation for low medium and high as my equation and how can express this in context or i have to prepare a full calibration curve to extract a new equation
Hi Ahmed,
In analytical chemistry, it is advisable to construct your own calibration curve for quantitation purpose if you have the analytical standards. Check for linearity and residual. If possible, prepare the standards fresh everytime you need to do the quantitation work.
Dear Ahmed,
You state that the method you are following has a validated calibration curve. This would lead one to believe that when the method for a particular analyte was developed, a linear curve occurred for that analyte, within a stated concentration range.
As the validated method was perhaps developed using a different instrument and with different batches of reagents, you are correct in measuring the signal from some standards. Often a full calibration curve is not required, as you are confining your new analysis to the range and stipulations of the validated method.
Many analysts would make up two replicate standards at around the expected concentration of the sample. They would then measure the signal from those replicates and compare it to the signal from the sample, in order to calculate the concentration of the analyte in the sample.
Kind regards,
Ade Kujore
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Cecil Instruments Limited
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Hi, I think you should do your self calibration. For every series of measurements you must do new calibration, you cannot use previous calibration to do calculation. For analysis you must have a validated method, and you must prove the method still valid during application (you must do internal QC). See guidance from thew Eurachem.
https://www.eurachem.org/images/stories/Guides/pdf/MV_guide_2nd_ed_EN.pdf
I am agreeing with Ade. You seem to have confirmed the validated curve
with your own equipment and you should retain this confirmation with your study data. In legal blood alcohol analysis, this is often done. But if the results of the confirmation show "significant" deviation, a new calibration curve is created.