Which solution from the Chemical Solutions DIY Qualification Kits do I use for injector carry over testing - FAQ
Date: 7-APRIL-2012 Last Updated: 5-JULY-2025
For evaluating injector carryover in your HPLC system, use the L6 solution provided in one of the Chemical Solutions "Do It Yourself" HPLC Qualification Kits.
Why L6?
- L6 contains the highest concentration of caffeine in the kit: 0.3490 mg/mL
- This high concentration makes it the most likely to reveal residual analyte left in the injector, tubing, or valve components after an injection
- It provides a worst-case scenario for assessing system cleanliness and autosampler performance
Carryover Testing Tip
After injecting L6, follow with a blank injection (mobile phase only). Any residual peak in the blank indicates carryover. This test is especially important for:- Regulated environments (e.g., GMP, GLP)
- Trace-level analysis
- Autosampler performance qualification