In this study, the stability of the chemical composition of lipsticks after exposure to various factors (substrate, time, individual variability, the impact of smoking, the effect of consuming beverages) and storage conditions (laboratory, insolation, without access to light) was examined. The following three analytical methods were used in the study: Attenuated Total Reflection technique (ATR), Gas Chromatography coupled to Mass Spectrometry (GC-MS) and Micellar Electrokinetic Capillary

more »

... ography (MEKC). Seven red lipsticks characterized by different chemical composition were analyzed. The analysis of variance (ANOVA) was used to estimate the impact of a given factor. It was noticed the lack of influence of individual variability, cigarette smoking and consumed beverages on the stability of the chemical composition of lipsticks. On the other hand, the changes in the chemical composition in lipstick traces depending on the time and storage conditions can be observed - especially when using the GC-MS method. In most cases, the results also indicated the possibility of identifying the lipstick left as a trace, using the ATR and MEKC method even after exposure to various factors and storage conditions. However, the main problem in the case of the ATR analysis is the occurrence of interference originating from the surface on which the trace of lipstick was applied. Ultimately, the conducted research provided evidence for the effectiveness of the MEKC method to the application in forensic science investigation.