Troubleshooting Peak Area Variation Between Injections

Created by Paola Labarbuta 7 months ago | Last modified by Carlos Vargas 20 days ago

This Information Applies To: All Agilent HPLC Autosampler modules

Issue:

Nonreproducible peak areas between injections, using the same sample and the same experimental conditions.

Resolution:

The issue may come from different sources, it is recommended to verify all the following ones for a successful troubleshooting.

Warning: When opening capillary or tube fittings, solvents may leak out. Observe appropriate safety procedures (for example, wear goggles, safety gloves and protective clothing) as described in the material handling and safety data sheet supplied by the solvent vendor, especially when toxic, or hazardous solvents are used.

Vials
Use only Agilent vials, the shape, and the material is optimized for maximizing instrument precision.
Do not overfill the vials. Fill the vial up to 1/2 to 2/3 of the total volume.
Experimental conditions
Make sure that the same solvents were used between the runs.
Keep the room temperature constant and under 25 degrees Celsius.
Acquisition method settings
Optimize the draw speed decreasing it down to 50µL/min. The default settings are at 200µL/min, but this speed may be too high for viscous samples.
Hardware
The issue may reside in the Autosampler. A leakage is one of the frequent causes, make sure that all the autosampler connections are tight and there is no leaks between the needle and needle seat.