Determination of artificial sweeteners in water samples by solid-phase extraction and liquid chromatography–tandem mass spectrometry

The development and performance evaluation of an analytical method for the determination of six artificial sweeteners in environmental waters using solid-phase extraction (SPE) followed by liquid chromatography–tandem mass spectrometry are presented. To this end, different SPE alternatives have been evaluated: polymeric reversed-phase (Oasis HLB, Env+, Plexa and Strata X), and mixed-mode with either weak (Oasis WAX) or strong anionic-exchange (Oasis MAX and Plexa PAX) sorbents. Among them, reversed-phase sorbents, particularly Oasis HLB and Strata X, showed the best performance. Oasis HLB provided good trueness (recoveries: 73–112%), precision (RSD < 10%) and limits of quantification (LOQ: 0.01–0.5 μg/L). Moreover, two LC separation mechanisms were evaluated: reversed-phase (RPLC) and hydrophilic interaction (HILIC), with RPLC providing better performance than HILIC. The final application of the method showed the presence of acesulfame, cyclamate, saccharin and sucralose in the wastewater and surface water samples analyzed at concentrations up to 54 μg/L.

► Comparison of polymeric reversed-phase and mixed-mode anionic-exchange sorbents.
► Mixed-mode sorbents led to incomplete elution or breakthrough for several analytes.
► Oasis HLB and Strata X sorbents provided the best performance.
► Evaluation of reversed-phase (RPLC) vs. hydrophilic interaction (HILIC).
► NHDC and ASP concentrations were reduced in wastewater with the storage time.