Home >
Community >
How are Internal (Deuterated) Standards (IS) handled in Sciex OS?
Upvote
41
Downvote
+ Solid phase extraction
+ Chemistry
+ Internal standard
+ Hplc-ms
Posted by
Abe De Jong
How are Internal (Deuterated) Standards (IS) handled in Sciex OS?
Sciex software is not smart than you think. It cannot know if you spike the IS or standards nor passing SPE. The software just calculate the integrated peak area for both peaks of analyte and IS, then plot them by analyte concentration / IS concentration for X axis and analyte peak area / IS peak area for Y axia. Finally, apply the "unknown" sample peak area / IS peak area on the calibration curve to calculate the "unknown" concentration. If the sample type is "Quality Control" or "Standard", and there is concentration keyed in under "Analyte Concentration", then the "Accuracy" would show the number which is from "Calculated concentration / analyte concentration" times 100%, and this is called "recovery". Unfortunately, it could not be a "recovery" for SPE. To evaluate the SPE recovery, you have to prepare matrix matched calibration curve, blank, pre-spike (spike standard before SPE), post-spike (spike standard after SPE) and QC samples with the same concentration of IS (spike IS with sample preparation". The recovery will be (post-spike concentration / pre-spike concentration) times 100%. You can also calculate the IS intensity or peak area for both pre-spike and post-spike sample to evaluate the SPE recovery by loss rate of IS.
Sciex software is not smart than you think. It cannot know if you spike the IS or standards nor passing SPE. The software just calculate the integrated peak area for both peaks of analyte and IS, then plot them by analyte concentration / IS concentration for X axis and analyte peak area / IS peak area for Y axia. Finally, apply the "unknown" sample peak area / IS peak area on the calibration curve to calculate the "unknown" concentration. If the sample type is "Quality Control" or "Standard", and there is concentration keyed in under "Analyte Concentration", then the "Accuracy" would show the number which is from "Calculated concentration / analyte concentration" times 100%, and this is called "recovery". Unfortunately, it could not be a "recovery" for SPE. To evaluate the SPE recovery, you have to prepare matrix matched calibration curve, blank, pre-spike (spike standard before SPE), post-spike (spike standard after SPE) and QC samples with the same concentration of IS (spike IS with sample preparation". The recovery will be (post-spike concentration / pre-spike concentration) times 100%. You can also calculate the IS intensity or peak area for both pre-spike and post-spike sample to evaluate the SPE recovery by loss rate of IS.
Sciex software is not smart than you think. It cannot know if you spike the IS or standards nor passing SPE. The software just calculate the integrated peak area for both peaks of analyte and IS, then plot them by analyte concentration / IS concentration for X axis and analyte peak area / IS peak area for Y axia. Finally, apply the "unknown" sample peak area / IS peak area on the calibration curve to calculate the "unknown" concentration. If the sample type is "Quality Control" or "Standard", and there is concentration keyed in under "Analyte Concentration", then the "Accuracy" would show the number which is from "Calculated concentration / analyte concentration" times 100%, and this is called "recovery". Unfortunately, it could not be a "recovery" for SPE.
To evaluate the SPE recovery, you have to prepare matrix matched calibration curve, blank, pre-spike (spike standard before SPE), post-spike (spike standard after SPE) and QC samples with the same concentration of IS (spike IS with sample preparation". The recovery will be (post-spike concentration / pre-spike concentration) times 100%. You can also calculate the IS intensity or peak area for both pre-spike and post-spike sample to evaluate the SPE recovery by loss rate of IS.
Sciex software is not smart than you think. It cannot know if you spike the IS or standards nor passing SPE. The software just calculate the integrated peak area for both peaks of analyte and IS, then plot them by analyte concentration / IS concentration for X axis and analyte peak area / IS peak area for Y axia. Finally, apply the "unknown" sample peak area / IS peak area on the calibration curve to calculate the "unknown" concentration. If the sample type is "Quality Control" or "Standard", and there is concentration keyed in under "Analyte Concentration", then the "Accuracy" would show the number which is from "Calculated concentration / analyte concentration" times 100%, and this is called "recovery". Unfortunately, it could not be a "recovery" for SPE.
To evaluate the SPE recovery, you have to prepare matrix matched calibration curve, blank, pre-spike (spike standard before SPE), post-spike (spike standard after SPE) and QC samples with the same concentration of IS (spike IS with sample preparation". The recovery will be (post-spike concentration / pre-spike concentration) times 100%. You can also calculate the IS intensity or peak area for both pre-spike and post-spike sample to evaluate the SPE recovery by loss rate of IS.
More
VOTE