# matrix-matched calibration curve

Hello, everyone! I need software setup instrucitons (Mass hunter 10.2; GC-(QQQ)MS/MS) for using matrix matched standards in which we have some of our analytes present in matrix. So, we have matrix (where we detected 2 out of seven analytes), and we used that matrix for setting up our calibration curve.

• Hi, It sounds like you want to do calibration approach called Standard Addition? If so in Quant there is an option for this under the edit method settings. Go to Global Setup. There should be an option for standard addition (bottom row). If its not there, I forget how to get it to appear there. But there is a way!

• Yes we did that. I just need the logic here. So first picture is when standard addition is unchecked, and the second with standard addition checked. I do not understand how does software apply this and does its calculations. Can someone explain?

• Hello  ,

The method of standard addition requires that you run each sample with its own spiked set of standards. The batch would look like this.

Here is the explanation from the Quant Dataset manual.

StandardAddition changes the association between samples and their “calibration” samples. The purpose of standard addition is to quantitate whenever the matrix of a sample changes the analytical sensitivity of the method.

StandardAddition is a technique that introduces a standard of your target compound directly into the analytical sample. After estimating the amount of target analyte present in the sample, samples are then spiked with known concentrations. By extrapolating the curve from the spiked samples, the original amount present in the sample can be determined. This technique assumes that the response for that particular analyte is linear in the concentration range of the sample.

The purpose of the spiked standards is to establish an analytical curve and determine the response factor for the target analyte. With the responses obtained from the target analyte in both the original sample and the spiked samples, the responses are used to calculate the method specific response factor for the target analyte. That response factor is subsequently used to determine the concentration of the unknown based on the responses of the unknown and the “standards”.

• Thank you, this is clear. What I want, and I hope I will be clear. So we have sample DVNK9 which is matrix which we used to prepare matrix-matched standards MM1, MM2 and MM3. But, matrix contains certain amount of our analytes.

In the second picture is the batch with our samples and response check standards. How do we arrange the batch and what options need to be assigned for software to calculate concentrations in samples based on calibration curve made with standards, but to take into account analytes that are detected in matrix itself?

• Hello  ,

You may want to investigate using the blank offset option for the calibration curve. Details can be found in this discussion.

(+) "Blank Offset" in MH Quantitative Software - Forum - Mass Spectrometry Software - Agilent Community

It can be useful to correct for a compound that is present at some background level in blanks and standards. I'm not certain if you will be able to use this if you are running samples prepared in matrix but no blanks.

It may be best to reach out to your local support team for further support. They will be able to work directly with you on your data and workflow to provide you with the best options for your analytical requirements.