Troubleshooting Problems with Chromatogram

A chromatogram is a graphical depiction of the chromatographic separation of a mixture of components in a sample. The chromatogram contains vital information about the sample's composition, purity, and identification. However, the chromatogram may not always be adequate due to a variety of factors such as column difficulties, sample preparation, and equipment issues. In this post, we will go over some of the most prevalent chromatogram difficulties and how to resolve them.

Problem #1: Poor peak shape

Poor peak shape is a typical issue in chromatography and can be caused by a variety of factors, including issues with the column, injection, or mobile phase. To begin troubleshooting this issue, inspect the column for any damage or contamination. Check the injection procedure and ensure that the sample is correctly prepared if the column is clean and undamaged. If these methods do not resolve the issue, inspect the mobile phase for problems such as pH or buffer concentration.

Problem #2: Baseline noise

Baseline noise can develop for a variety of causes, including instrument faults or problems with the mobile phase. To begin troubleshooting this issue, inspect the instrument for any abnormalities such as electrical interference, detector noise, or pump difficulties. Check the mobile phase for concerns such as contamination or buffer concentration if the equipment is performing properly.

Problem #3: Retention time shifts

Retention time shifts can occur due to several reasons, including changes in column temperature, mobile phase composition, or detector sensitivity. To troubleshoot this problem, first, check the column temperature and make sure that it is stable. Next, check the mobile phase composition and make sure that it is consistent. Finally, check the detector sensitivity and make sure that it is properly calibrated.

Problem #4: Peak tailing

Peak tailing is a common problem in chromatography and can occur due to several reasons, including problems with the column, injection, or mobile phase. To troubleshoot this problem, first, check the column for any damage or contamination. Next, check the injection method and make sure that the sample is properly prepared. Finally, check the mobile phase for issues such as pH or buffer concentration.

Problem #5: Poor resolution

Poor resolution is a common problem in chromatography and can occur due to several reasons, including problems with the column, injection, or mobile phase. To troubleshoot this problem, first, check the column for any damage or contamination. Next, check the injection method and make sure that the sample is properly prepared. Finally, check the mobile phase for issues such as pH or buffer concentration.

Troubleshooting Problems with Chromatogram

Many problems in the LC system show up as changes in the chromatogram. Some of these can be solved by changes in the equipment; however, others require modification of the assay procedure. Selecting the proper column type and mobile phase are keys to “good chromatography.”

Peak Tailing