Organic pollutants in surface waters from Portugal using chemometric interpretation

Area of Science:

• Environmental Chemistry
• Analytical Chemistry

Background:

• Monitoring of organic pollutants in surface waters is crucial for assessing environmental and human health risks.
• European Union directives set limits for contaminants in water, necessitating regular analysis.

Purpose of the Study:

• To determine the levels of 72 organic compounds in Portuguese surface waters.
• To identify and characterize contamination sources using chemometric methods.

Main Methods:

• Monthly sampling over six months (April-September 1999) at 45 locations.
• Automated Solid Phase Extraction (SPE) followed by Gas Chromatography-Mass Spectrometry (GC/MS) analysis.
• Principal Component Analysis (PCA) for contaminant source identification.

Main Results:

• Detected compounds included herbicides (atrazine, simazine), pesticides, and phenols.
• Some samples exceeded the European Union Drinking Water Directive limits for atrazine, alachlor, and simazine.
• High concentrations of tributhylphosphate and 2,4,6-trichlorophenol were found near industrial areas.

Conclusions:

• The study identified key organic contaminants in Portuguese surface waters.
• PCA effectively resolved contamination sources and their spatial-temporal distribution.
• Monitoring revealed exceedances of drinking water standards, highlighting potential risks.