Matrix effects of milk, dairy factory wastewater and soil water on the determination of disinfection by-products and para-cresol using solid-phase microextraction



Assessing pollutant concentrations can be hampered by the complex matrices found in the dairy supply/processing chain. Matrix effects were examined using solid-phase microextraction (SPME) used to sample haloacetic acid methyl esters (HAAMe) and para-cresol. In general, HAAMe were more difficult to detect with a polydimethylsiloxane fibre than with carboxen–polydimethylsiloxane fibre. Headspace sampling generally provided better detection of HAAMe than direct immersion with the reverse true for para-cresol. For para-cresol, equivalent ratios up to 18.8 were detected. Other compounds detected included sulphides, VOC's, phenols and indoles. For milk samples, most compounds collected by SPME were found using direct immersion.