Dispersive microextraction techniques as efficient strategies for the analysis of saliva: A comprehensive review

This review article brings together two of the current hot-spots in the field of analytical chemistry, and more specifically in the sample preparation stage: the use of dispersive microextraction techniques, and the analysis of saliva. Due to saliva collection is minimally invasive, it is increasingly being considered in bioanalysis. Moreover, bioanalysis is routine and agglutinates a high number of samples demanding for fast results, thus high-throughput assays are highly required. On the other hand, if something characterizes biological matrices, including saliva, is their complex composition. To adapt the matrix to the analytical method to be applied and to avoid as far as possible the matrix effect, an efficient sample preparation stage is required. To this regard dispersive microextraction techniques, as rapid, efficient and sustainable sample preparation approaches, play a crucial role. In the first part of the review, different workflows for the collection and pretreatment will be briefly described, placing special emphasis on advice to follow. Then, a compilation of the different applications of dispersive techniques for the analysis of saliva is presented, in which the trends observed in both specific analytes and microextraction approaches used are discussed.