Assessing pharmaceuticals in the green seaweed Ulva lactuca through a multi-residue UHPLC-ToF-MS strategy.

Seaweeds have become an important asset in several sectors, including the food and feed industries, cosmetics, and pharmaceuticals, among others. Whether harvested or reared, interest in algae has been growing worldwide due to the resources they offer, including proteins, vitamins, minerals, carbohydrates, essential fatty acids, and dietary fiber, as well as sources of biologically active compounds. However, given their morphology and physiology, as well as their harvest and cultivation environments, algae are prone to the presence of hazards, including pharmaceuticals taken up from the water. Thus, to ensure human and animal safety as well as environmental health, monitoring is essential. Therefore, this work describes the development and validation of a sensitive screening and confirmatory analytical method based on ultra-high-performance liquid chromatography coupled with time-of-flight mass spectrometry (UHPLC-ToF-MS). This multi-residue method enables the determination of 62 pharmaceuticals distributed between 8 therapeutic classes and was fully validated according to Commission Implementing Regulation (EU) 2021/808.