Advanced Analytical Approaches for Phenolic Compounds in Groundwater: A PRISMA Systematic Review

Groundwater is of vital significance to achieve the 2030 Agenda and its Sustainable Development Goals (SDGs); nevertheless, it remains vulnerable to contamination from phenolic compounds. This systematic review critically evaluates the chromatographic and spectrometric techniques applied in real-case groundwater contamination studies involving phenolic compounds. It highlights advances, limitations, and research gaps. A comprehensive research strategy retrieved a total of 345 publications from the Scopus and Web of Science databases, of which 52 (from the years 1984 to 2023) met the PRISMA criteria. The review identified 107 phenolic compounds across 25 countries. Temporal and spatial analyses, source identification, and pollutant profiles were systematically assessed per country. The study also mapped priority (n = 11) and hazardous (n = 27) phenolic compounds according to the USEPA, comparing their detectability across analytical methods. The most frequently applied techniques were LC-MS and LC-MS/MS, while GC-MS demonstrated competitive performance when combined with derivatization. The study found that contamination was predominantly reported in the Global North, with industrial and domestic sewage being the main sources. The highest concentrations reported were 40 × 106 ng/L for 4-methylphenol and 50 × 106 ng/L for phenol, both of which are hazardous substances typically linked to industrial/domestic effluents and the use of pesticides. These findings highlight the imperative for regulatory measures and international scientific collaboration to enhance groundwater monitoring, particularly in the Global South, where data scarcity persists.