Application of Bar Adsorptive Microextraction for the Determination of Levels of Tricyclic Antidepressants in Urine Samples  
[PERSON]  
1 Centro de Quimica Estrutural, Faculdade de Ciencias, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal, [EMAIL_ADDRESS] (M.N.O. ); [EMAIL_ADDRESS] (O.C.G. ); [PERSON].M.A. );  
Moleular Pathology and Forensic Biochemistry Laboratory, Centro de Investigacao Interdisciplinar Egas Moniz (CiiEfM), Instituto Universitario Egas Moniz (UIEM), Campus Universitario--Quimta da Granja, Monte da Caparica, 2829-511 Caparica, Portugal 1  
Monica de Quimica Estrutural, Faculdade de Ciencias, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal, [EMAIL_ADDRESS] (M.N.O. ); [EMAIL_ADDRESS] (O.C.G. ); [PERSON].M.A. );  
Monica de Quimica Estrutural, Faculdade de Ciencias, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal, [EMAIL_ADDRESS] (M.N.O. ); [EMAIL_ADDRESS] (O.C.G. ); [EMAIL_ADDRESS] (S.M.A. );  
[PERSON] Quimica Estrutural, Faculdade de Ciencias, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal, [EMAIL_ADDRESS] (M.N.O. ); [EMAIL_ADDRESS] (O.C.G. ); [EMAIL_ADDRESS] (O.C.G. ); [EMAIL_ADDRESS] (S.M.A. );  
[PERSON], Faculdade de Ciencias, Universidade de Lisboalow self-esteem, difficulty to sleep, loss of appetite, fatigue, low concentration, and poor decision making. In the most severe cases it can even lead to suicide. Antidepressants are an effective way of treatment, which allows the patients to live a normal life. The first commercially available antidepressant, introduced in 1955, was impiramine, a tricyclic antidepressant (TCA) still widely used today [1; 2; 3]. However, these compounds have narrow therapeutic range (between 50 and 300 \(\upmu\)g L\({}^{-1}\) in plasma). When concentration exceeds 500 \(\upmu\)g L\({}^{-1}\), toxic effects, such as high body temperature, sleepiness, confusion, cardiac arrest, among others, can happen and, when it rises to 1000 \(\upmu\)g L\({}^{-1}\), death may also occur. Therefore, it is essential to develop sensible, accurate and simple analytical methods together with suitable sample preparation approaches for the determination of these pharmaceutical compounds in forensic matrices [4; 5; 6]. Nevertheless, when dealing with very complex matrices like biological matrices, a sample preparation step is always a must. In the past decades there has been a concern in making sample preparation more eco-friendly, leading to new strategies that include several innovative concepts, namely, miniaturization, simplification, much higher selectivity and sensitivity, the elimination of toxic organic solvents, and reduction the sample amount. Apart from other microextraction approaches such as solid-phase microextraction (SPME) or stir bar sorptive extraction (SBSE) [7; 8; 9; 10; 11; 12; 13], bar adsorptive microextraction (BA\(\upmu\)E), which was introduced in the last decade, presents several advantages and has shown great simplicity and versatility by allowing the choice of sorbent coating for each particular type of application. Materials such as activated carbons (ACs) prepared from several sources, alumina, silica, cork, polystyrene divinylbenzene (PS-DVB), modified pyrroline, silica-based polymers, and nanomaterials, such as carbon nanotubes, and multi-walled carbon nanotubes have been used, demonstrating great performance as sorbent phases for BA\(\upmu\)E technique [14; 15; 16; 17; 18; 19]. Nevertheless, the preparation and application of new materials with specific sorption characteristics is still very important for particular applications, especially those from ecological sources, such as biomaterial waste. In addition, the BA\(\upmu\)E devices can be lab-made, the experimental procedure is easy to implement and cost-effective, requires low sample volume and negligible amounts (100 \(\upmu\)L) of organic solvent during the back-extraction step, presents remarkable performance, high enrichment factors and analytical limits at the trace level.