## 1 Introduction  
In the last decades, many improvements have been introduced in the field of sample preparation, aiming at simplification, miniaturization, easy manipulation, as well as the reduction of the use of toxic organic solvents, in compliance with the green analytical chemistry (GAC) principles. In this context, the sorption-based techniques have played an important role, mainly for trace analysis of complex matrices. In this regard, solid phase microextraction (SPME) [1], stir bar sorptive extraction (SBSE) [2], and, more recently, bar adsorptive microextraction (BA\(\mu\)E) [3, 4] are good examples of effective sample-enrichment approaches. In BA\(\mu\)E, a bar-shaped polypropylene device (7.5 mm in length and 3 mm in diameter) coated with a convenient sorbent phase is used, simultaneously with a conventional Teflon magnetic stirring bar at the bottom of the sampling flask. This technique operates under the floating sampling technology mode, which uses an analytical device lighter in weight in comparison with water density. The BA\(\mu\)E devices are easily lab-made by coating the polypropylene support bars with a convenient adhesive, where the sorbent materials (\(<\)5 mg) are fixed. BA\(\mu\)E is very cost-effective, and the great advantage over other sorption-based methodologies is that the analytical devices can be easily coated with the most selective sorbent phases, according to the characteristics of the target analytes. Furthermore, this technology is also in compliance with GAC principles, needing just around 100 uL of an appropriate organic solvent during the back-extraction stage, performed through liquid desorption (LD). In a previous work [5], novel improvements were introduced in this technique, by designing new-generation BAuE devices in order to reduce the number of steps involved during the back-extraction stage. It allowed the implementation of an innovative analytical cycle, with an effective microextraction stage together with a back-extraction stage performed in \"only single LD step\", for interface enhancement with the instrumental systems. From the analytical point of view, the new-generation BAuE approach is user-friendly, as well as much more competitive for the routine work over other well-established microextraction techniques. Furthermore, due to the simplicity, eco-friendliness and cost-effectiveness involved, the reutilization is not considered in this novel analytical approach. To show the versatility of the new-generation devices recently introduced [5], the present contribution aims to apply them to monitor trace levels of highly polar compounds, such as hydrophilic ultraviolet (UV) filters in real samples. UV filters are a large group of chemical compounds used to block or absorb UV light and protect the skin from the harmful effects of sun radiation. They are extensively present in a variety of personal care products, such as sunscreen lotions, skin care, facial makeup, and lip care products. These compounds are considered persistent pollutants once they are continuously released into the aquatic ecosystems through recreational aquatic activities or industrial and urban wastewaters. As a result, UV filters have been found at trace levels in several environmental matrices, mainly in surface [6], sea [7], as well as tap [8] waters, and their effects and consequences are issues of increasing concern. Numerous reports can be found in the literature regarding the determination of lipophilic UV filters from environmental water samples using microextraction techniques [9; 10; 11]. Meanwhile, few studies aim at the analysis of very polar UV filters and, most of them, use non-green analytical techniques such as solid phase extraction [12; 13]. Yet, only one paper can be found in the literature using a miniaturized technique for the extraction of these hydrophilic UV filters compounds, the stir bar sorptive-dispersive microextraction mediated by magnetic nanoparticles-nylon 6 composite [14].