Microextraction sample preparation techniques in forensic analytical toxicology

Sample preparation is a critical step in forensic analytical toxicology. Different extraction techniques are employed with the goals of removing interferences from the biological samples, such as blood, tissues and hair, reducing matrix effects and concentrating the target analytes, among others. With the objective of developing faster and more ecological procedures, microextraction techniques have been expanding their applications in the recent years. This article reviews various microextraction methods, which include solid-based microextraction, such as solid-phase microextraction, microextraction by packed sorbent and stir-bar sorptive extraction, and liquid-based microextraction, such as single drop/hollow fiber-based liquid-phase microextraction and dispersive liquid-liquid microextraction, as well as their applications to forensic toxicology analysis. The development trend in future microextraction sample preparation is discussed.