After LC-MS analysis using the Pierce Retention Time Calibration Mixture (PRTC) or Pierce LC-MS/MS System Suitability Standard (7x5 mix), the chromatography is drifting over time. How do I fix the chromatography so that it is more reproducible?
We recommend purging the LC system and checking the flow meter calibration. We also recommend checking mobile phase solvents and LC gradient. Evaluate and replace the column if needed and rerun the Pierce Retention Time Calibration Mixture (PRTC)/Pierce LC-MS/MS System Suitability Standard (7x5 mix) to verify that the chromatography is consistent in replicate runs.
Find additional tips, troubleshooting help, and resources within our Mass Spectrometry Support Center.
How do I analyze the data for Pierce Retention Time Calibration Mixture (PRTC) and Pierce LC-MS/MS System Suitability Standard (7x5 mix) standard?
Create a new Skyline document containing 15 PRTC heavy isotope-labeled peptides. The Skyline document can be used for the DDA data analysis using MS1 filter or for the PRM/SRM data analysis with targeted MS filters. The Skyline document for 7x5 standard is available as a web download document. Please refer 7x5 standard label for detailed information. Alternatively, the 7x5 standard data can be analyzed in Chromeleon software using the pre-built report template (web download document).
Find additional tips, troubleshooting help, and resources within our Mass Spectrometry Support Center.
What is the difference between Pierce Retention Time Calibration Mixture (PRTC) and Pierce LC-MS/MS System Suitability Standard (7x5 mix)?
Pierce Retention Time Calibration Mixture (PRTC) is a mixture of 15 peptides with varying hydrophobicity used to determine the quality of nano and capillary flow LC chromatography and column performance. The Pierce LC-MS/MS System Suitability Standard (7x5 mix) contains 7 of 15 PRTC peptides with five isotopologue versions of each peptide containing no heavy, 1 heavy, 2 heavy, 3 heavy, and 4 heavy isotope-labeled amino acids. The isotopologues for each peptide are provided at a distinct concentration to generate seven standard curves to assess system performance. In addition to evaluation of LC chromatography, this standard is also used to assess the dynamic range and sensitivity of the LC-MS system.
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How do I assess my LC-MS system performance?
The best way to assess the performance of an entire LC-MS system is using a mass spectrometry calibration solution, peptide retention time standards (Pierce Peptide Retention Time Calibration Mixture (PRTC), Cat. No. 88321 and Pierce LC-MS/MS System Suitability Standard (7 x 5 Mix), Cat. No. A40010), and a known standard sample, e.g., Pierce BSA Digest (Cat. No. 88341), Pierce 6 Protein Digest (Cat. No. 88342), or Pierce HeLa Protein Digest Standard (Cat. Nos. 88328, 88329) specific to your application. We recommend frequent assessment of LC-MS system performance on a routine basis to compare results over time.
Find additional tips, troubleshooting help, and resources within our Mass Spectrometry Support Center.
Which standards and calibrants do you recommend using for assessing LC-MS system suitability?
Here are our recommendations:
- Pierce Peptide Retention Time Calibration Mixture (Cat. No. 88321) for LC system and gradient optimization
- Pierce BSA Protein Digest, MS grade (Cat. No. 88341), Pierce 6 Protein Digest, equimolar, LC-MS grade (Cat. No. 88342), and Pierce HeLa Protein Digest Standard (Cat. Nos. 88328, 88329) for "bottom up" LC-MS method optimization and LC-MS suitability assessment
- Pierce LC-MS/MS System Suitability Standard (7 x 5 Mix) (Cat. No. A40010) for assessing the gradient, sensitivity, and dynamic range of the LC-MS system for discovery and targeted peptide quantitative workflows
- Pierce TMT11plex Yeast Digest Standard (Cat. Nos. A40938, A40939) for assessing system performance for TMT-based quantitative workflows
- Pierce Intact Protein Standard Mix (Cat. Nos. A33526, A33527) for "top down" LC-MS method optimization and LC-MS suitability assessment
Find additional tips, troubleshooting help, and resources within our Mass Spectrometry Support Center.