The Origins, Identification, and Solutions for Ghost Peaks in Gas Chromatography

Abstract

Gas chromatography is a highly efficient, sensitive, and selective method for separation and analysis. This technique is extensively used for the analysis of volatile or semi-volatile compounds that are thermally stable across a wide range of industries. However, ghost peaks may severely interfere with qualitative and quantitative analysis of target compounds, primarily by reducing resolutions, inducing linearity deviations, increasing the limits of detection and quantification, or decreasing accuracy and precision. Therefore, excluding ghost peak interference is a prerequisite for obtaining accurate results. This review compiles various common sources responsible for ghost peak problems, such as cross-contamination of samples, sample decomposition, septum bleed and adsorption, liner reactivity, column bleed, memory effects, inappropriate analytical parameters, mismatched solvent polarity with stationary phases, and contamination from carrier gases, gas tubing, inlet plated seals, the split vent, capillary columns, detectors, and so on. Furthermore, the logical judgment process of determining the origins of ghost peaks is concisely and clearly described in the form of a flowchart. Additionally, several useful troubleshooting methods are introduced, such as the double blank test, the condensation test, and the inlet contamination test. They are helpful for GC analysts to quickly diagnose and eliminate problems caused by ghost peaks.