Multiresidue analytical method for pharmaceuticals and personal care products in sewage and sewage sludge by online direct immersion SPME on-fiber derivatization - GCMS.

The work here presented aimed at developing an analytical method for the simultaneous determination of 22 pharmaceuticals and personal care products, including 3 transformation products, in sewage and sludge. A meticulous method optimization, involving an experimental design, was carried out. The developed method was fully automated and consisted of the online extraction of 17 mL of water sample by Direct Immersion Solid Phase MicroExtraction followed by On-fiber Derivatization coupled to Gas Chromatography – Mass Spectrometry (DI-SPME – On-fiber Derivatization – GC – MS). This methodology was validated for 12 of the initial compounds as a reliable (relative recoveries above 90% for sewage and 70% for sludge; repeatability as %RSD below 10% in all cases), sensitive (LODs below 20 ng L−1 in sewage and 10 ng g−1 in sludge), versatile (sewage and sewage-sludge samples up to 15,000 ng L−1 and 900 ng g−1, respectively) and green analytical alternative for many medium-tech routine laboratories around the world to keep up with both current and forecast environmental regulations requirements. The remaining 10 analytes initially considered showed insufficient suitability to be included in the final method. The methodology was successfully applied to real samples generated in a pilot scale sewage treatment reactor.