Calculating unknown concentration by using Millinum32
Posted: Tue May 13, 2008 1:43 pm
Dear Sir
I constructed calibration curve is process by creating processing method, also unknown sample chromatogram was processed by using the same method. I got the equation from software by using 1/x as weighing factor y=0.00144X+0.02694. As the calibration plot was plotted between the Area ratio Vs Concentration. Here in this calibration plot equation y is area ratio where X is concentration.
In case of unknown sample the area of analyte is 64152 and Internal STD is 180630. If we want to use the equation (y=0.00144X+0.02694) that means we have to use area ratio of Analyte to IS. The area ratio is 0.3552. If we will put this value in to equation y=0.00144X+0.02694 as ‘y’ value we should get concentration of unknown sample. As we will put this value in this equation the concentration for unknown sample is 277.96ng/ml.
But if will see the chromatogram, by using the processing method (which used for construction of calibration curve) concentration is 11374.264ng/ml. as y=mx+C is worldwide accepted equation to get the concentration of unknown sample by using response.
So why these descrapencies are there? Is there any thing we have to change setting in software as I am using Millinium32 version4.0 software.
If any another method is there to calculate the concentration from software, kindly intimate us.
If any one can solve problem wants the unknown sample chromatogram with Calibration curve kindly provide the e-mail ID as can not attach files here
Thanking you
PRASHANT
I constructed calibration curve is process by creating processing method, also unknown sample chromatogram was processed by using the same method. I got the equation from software by using 1/x as weighing factor y=0.00144X+0.02694. As the calibration plot was plotted between the Area ratio Vs Concentration. Here in this calibration plot equation y is area ratio where X is concentration.
In case of unknown sample the area of analyte is 64152 and Internal STD is 180630. If we want to use the equation (y=0.00144X+0.02694) that means we have to use area ratio of Analyte to IS. The area ratio is 0.3552. If we will put this value in to equation y=0.00144X+0.02694 as ‘y’ value we should get concentration of unknown sample. As we will put this value in this equation the concentration for unknown sample is 277.96ng/ml.
But if will see the chromatogram, by using the processing method (which used for construction of calibration curve) concentration is 11374.264ng/ml. as y=mx+C is worldwide accepted equation to get the concentration of unknown sample by using response.
So why these descrapencies are there? Is there any thing we have to change setting in software as I am using Millinium32 version4.0 software.
If any another method is there to calculate the concentration from software, kindly intimate us.
If any one can solve problem wants the unknown sample chromatogram with Calibration curve kindly provide the e-mail ID as can not attach files here
Thanking you
PRASHANT