Determination of benzophenone derivatives in wastewater by GC–MS/MS combined with in-port derivatization

The analysis of UV filters (UVFs) in water has become increasingly important due to their adverse effects on aquatic organisms and humans. This study describes a method for the determination of benzophenone derivatives UVF in wastewater samples. The selected UVFs are 2-hydroxy-4-methoxybenzophenone (BP-3), 2,4-dihydroxybenzophenone (BP-1), 4-hydroxybenzophenone (4HB), 2,2′-dihydroxy-4-methoxybenzophenone (DHMB) and lastly, 4,4′-dihydroxybenzophenone (4DHB). The method includes solid-phase extraction (SPE) of analytes from wastewater followed by on-line derivatization with bis(trimethylsilyl)trifluoroacetamide (BSTFA) and analysis with GC-MS/MS. Method validation studies resulted in good recoveries (86–112%), relative standard deviation RSD = 0.8 and 7.3%, the limits of detection LODs = 1.00–10.8 ng/L, and the limits of quantification LOQs = 3.00–32.3 ng/L. The method was successfully applied to domestic wastewater samples collected from influent and effluent of touristic hotels’ biological wastewater treatment plants. BP-3 (24–1765 ng/L), BP-1 (8–703 ng/L), 4HB (26–96 ng/L), and 4DHB (20–22 ng/L) were the common benzophenone derivatives in the influent wastewater while effluent contained mainly BP-1 (8–32 ng/L), 4HB (12–57 ng/L) and 4DHB (20–102 ng/L). These results indicate that BP-3 and BP-1 are biodegraded in the treatment processes. However, 4HB and 4DHB are resistant to degradation and they are the main benzophenone metabolites discharged to receiving media.