Miniaturization is a strategy employed in sample preparation that has gained much prominence in recent years due to the need to develop more efficient procedures that consume less solvent and time. The analysis of important families of contaminants, such as pesticides or polycyclic aromatic hydrocarbons (
PAH
s), in liquid samples has traditionally been conducted using conventional techniques, such as liquid–liquid extraction (
LLE
) and solid‐phase extraction (
SPE
). Although
SPE
uses much less amount of solvent than
LLE
, the volume can still be significant, making both techniques expensive and environment‐unfriendly procedures. The miniaturization of sample preparation processes has led to a new generation of techniques with improved characteristics. Different solid‐phase microextraction (
SPME
) techniques, including fibers, stir bar sorptive extraction (
SBSE
) and thin‐film microextraction (
TFME
), and automated techniques, such as in‐tube solid‐phase microextraction (
IT
‐
SPME
), have allowed the determination of different families of contaminant compounds, including emerging compounds in complex environmental waters, such as seawater, groundwater, or superficial water.
The emerging compounds are relatively unknown compounds that are not covered by the existing regulations; they are frequently detected in different environmental compartments in very low concentrations. For this reason, their analysis requires extraction, purification and preconcentration from the matrix and subsequent separation and detection systems that can measure these concentration levels.
In this chapter, we review the most recent applications of microextraction techniques based on solid phase coupled to liquid chromatography (
LC
) for the determination of different emerging contaminants in several water environmental matrices.