2018 Geballa-Koukoula, A.; Panderi, I.; Zervas, K.; Geballa-Koukoulas, K.; Kavvalou, E.; Panteri-Petratou, E.; Vourna, P.; Gennimata, D. A porous graphitized carbon LC-ESI/MS method for the quantitation of metronidazoleole and fluconazole in breast milk and human plasma. _J. Chromatogr. B_**2018**, _1084_, 175-184. Parla, A.; Zormpa, E.; Paloumpis, N.; Kabir, A.; Furton, K.; Roje, Z.; Samanidou, V.; Vrcek, I.V. ; Panderi, I. Determination of Intact Parabens in the Human Plasma of Cancer and Non-Cancer Patients Using a Validated Fabric Phase Sportive Extraction Reversed-Phase Liquid Chromatography Method with UV Detection. _Molecules_**2021**, _26_, 1526. _16.23. Simultaneous Quantitation of Three Ultraviolet Filters in Suncare Products by High-Performance Liquid Chromatography with Photodiode-Array (PDA) Detection_  
**P. Feidias 1**, **I. Balatsouka 1**, **E. Kalogria 1**, **S. Papageorgiou 2**, **A. Varvaresou 2 and I. Panderi 1,*  
1 Laboratory of Pharmaceutical Analysis, Division of Pharmaceutical Chemistry, Faculty of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis, Zografou, 15771 Athens, Greece  
2 Laboratory of Chemistry-Biochemistry-Cosmetic Science, Department of Biomedical Sciences, University of West Attica, 12210 Athens, Greece  
* Correspondence: irenepanderi@gmail.com  
Sun protection is not a modern occurrence. For centuries, people have used various means to protect themselves from solar ultraviolet (UV) radiation exposure. Early on, such protection was largely achieved by clothing and wide-brim hats. Generally speaking, the optical region of the solar spectrum consists of ultraviolet (UV), visible, and infrared (IR) radiation. The UV region has the highest energy and is responsible for the damage caused to skin and hair [1]. The UV region is divided into UVA (320-400 nm), UVB (290-320 nm), and UVC (200-290 nm). UVC, with the highest energy, is the most dangerous, but is absorbed before it reaches the earth. The development of modern sunscreens began in earnest during the 1930s. Through the course of the 20 th century, numerous UV filters with unique characteristics were introduced with the common property of reducing solar UV, principally short wavelengths (i.e., UVB (290-320 nm)). More recently, much effort has been devoted to the development of UV filters that absorb at longer wavelengths of UV or UVA (i.e., 320-400 nm). Chemical UV filters are organic molecules formed in general by one or more benzene rings and/or carbonyl groups, allowing a high electron delocalization that provides them with a high molar absorptivity in both UVA and UVB ranges [2,3]. 4-Methylbenzylidene camphor (4-MBC), octyl methoxycinnamate (OMC), and avobenzene (AVO) are three chemical UV filters which are widely used in sunscreen formulations, and, to this purpose, we thought that it would be of interest to develop a method for the quantitation of these UV filters in a suncare product. Regarding the commercial sample preparation, we used methanol as diluent and the ultrasonic bath for the extraction of the UV filters. Chromatographic separation was performed on a reversed-phase phenyl analytical column with photodiode-array detector (PDA), which allowed the elution of the analytes within 12 min. The assay was linear over a concentration range of 0.4 to 6 \(\mu\)g mL\({}^{-1}\) for 4-MBC, 1.2 to 18 \(\mu\)g mL\({}^{-1}\) for OMC, and 0.32 to 4.8 for AVO, and it was applied to the analysis of the UV filters in the suncare products. ## References  
* _Kedor-Hackmann et al. 2006_ Kedor-Hackmann, E.R.M. ; De Lourdes Perez Gonzalez, M.L. ; Singh, A.K. ; Santoro, M.I.R.M. Validation of a HPLC method for simultaneous determination of five sunscreens in lotion preparation. _Int. J. Cosmet. Sci._**2006**, _28_, 219-224. * Liu and Wu 2011 Liu, T.; Wu, D. Simultaneous determination of some ultraviolet-absorbing chemicals in sunscreen cosmetics using a high-performance liquid chromatography method. _Int. J. Cosmet. Sci._**2011**, _33_, 408-415. * Peruchi and Rath 2012 Peruchi, L.M.