Professional skills are considered particularly relevant within all the skills that a bachelor student must develop. They are achieved through a series of contents, skills and learning objectives that are often worked on in several subjects. Although the use of active teaching/learning (T/L) strategies has allowed a clear improvement in the students' learning process and their achievement of skills (due to the fact of diversifying teaching methodologies), there is still a significant number of students with a low overall performance who do not end up satisfactorily achieving these professional skills.

This situation may be linked to the different learning styles of the students. Although it has been shown that not all students learn in the same way, teachers often base the achievement of learning objectives or skills on a single type of activity or T/L strategy, which clearly benefits one group of students over the rest. To this situation, we must add a growing number of students with specific learning needs that clearly require adjustments to be able to develop their learning process. It is in this context that Universal Design for Learning (UDL), which aims to develop flexible learning environments to respond to the individual learning differences of our students, can play an important role.

The aim of this work was to promote the development of students' professional skills, related to the subject of Analytical Chemistry, through the incorporation of UDL in both teaching materials and T/L strategies. The teaching team participated in a 70-hour training on UDL that took place in the academic year 2022-2023, and the advantages and disadvantages of implementing this training for teachers at University level will be discussed.

Then, two examples of the implementation of UDL in Analytical Chemistry subjects during courses 2023-2024 and 2024-2025 will be discussed. The first experience aims to improve the learning skills of students in Analytical Chemistry laboratories through the observation, identification and evaluation of errors. For this purpose, a series of audiovisual supports (UDL adapted) that reflect common sources of errors in Analytical Chemistry laboratories were created. In the first approach, these supports show experimental procedures in which some of the most frequent errors that occur in the acquisition of a certain skill are shown. After viewing the material, students evaluate it to detect the errors, discuss their impact and propose a correction. The second part of the audiovisual material shows the procedure carried out correctly so that the student can check the proposed correction. This helps the students (independently of their specific learning requirements thanks to ULD) to develop their Learning and Responsibility Training Skill, through the capacity of analysis, the application of knowledge to practice, and the capacity to make decisions and adjustments to new situations. The second experience aims to improve the students’ capacity to select the best analytical methodology for a given analysis and to better reflect and accredit the student’s accomplished level on this capacity during evaluation. Thus, UDL adaptations in the wording of the final written assessment tests for the theoretical subject Instrumental Analysis were performed. In general, both strategies allowed to improve students’ professional skills when compared to those of previous courses where no UDL adaptation was employed.

Keywords: Universal Desing for Learning (UDL), Professional Skills, University, Analytical Chemistry Area.