Carryover and Contamination

Issue

• Carryover
• Contamination

Environment

LCMS

Resolution

1. Distinguish between true analyte carryover versus other forms of contamination
2. Apply systematic approach to reveal sources of carryover and/or contamination
3. Repair or replace defective components that contribute to carryover
4. Modify autosampler and/or LC parameters, especially chemistry

Refer to the attached document for additional information.

Analysis

Contamination must be distinguished from carryover. Identify and remedy its sources. Carryover can result from spatial pockets (tiny cracks, channels or gaps) or surfaces that hold residual analytes. Identify and remedy its sources. Hydrogen bonding, ionic, metallic and hydrophobic interactions between analytes and surfaces can be quenched by adding competitive inhibitors to the mobile phases and washes and/or by changing the chemistry of the surfaces.