Liquid chromatography
How should the LC-MS system be maintained for optimal performance?
Important cleaning notes: Frequent cleaning actions and rinsing methods are strongly recommended to minimize the risk of instrument contaminations or performance loss. For optimal time-efficiency, clean and rinse the instruments routinely between the ...
FIA chromatograms show signal suppressions
If the FIA chromatograms show signal suppressions, it is most likely either caused by the injection system or by an issue at the ion source. To solve this issue, please check the following parts at the LC-MS system: A small leakage or blockage at the ...
FIA blank contaminations
The contaminations could be eluting from the autosampler. To reduce the contaminations in the FIA blank injections, perform the following procedure: Install 10% MeOH in water on your FIA line and flush out tubing for 20 min at 0.5 mL/min Install ...
Why are the retention times shifted?
If the retention times are unstable across a plate or shifting over time: - Make sure the mobile phases are purged and there are no bubbles in the system. - Make sure no air is drawn or injected by the autosampler. - Make sure the entire LC-MS system ...
Unstable retention times
Retention time fluctuations during a measurement are usually caused by the LC system. The most common causes are 1. Pump malfunctions, e.g. defective check valves. 2. An imprecise gradient, e.g. by organics at the beginning of chromatography. How can ...