A late-eluting FIA signal indicates an increased dead volume between the autosampler and the ion source, which can impact chromatographic performance. To address this issue, consider the following:

• Capillary Length: How long is the capillary between the autosampler and the ion source?

• Number of Valves: How many valves are in use?

• Capillary Dimensions: What is the inner diameter of the capillaries in use?