Determination of parabens in wastewater samples via robot‐assisted dynamic single‐drop microextraction and liquid chromatography–tandem mass spectrometry

Abstract

Dynamic single-drop microextraction (SDME) was automatized employing an Arduino-based lab-made Cartesian robot and implemented to determine parabens in wastewater samples in combination with liquid chromatographytandem mass spectrometry. A dedicated Arduino sketch controls the autoperformance of all the stages of the SDME process, including syringe filling, drop exposition, solvent recycling, and extract collection. Univariate and multivariate experiments investigated the main variables affecting the SDME performance, including robot-dependent and additional operational parameters.Under selected conditions, limit of detections were established at 0.3 µg/L for all the analytes, and the method provided linear responses in the range between 0.6 and 10 µg/L, with adequate reproducibility, measured as intraday relative standard deviations (RSDs) between 5.54% and 17.94%, (n = 6), and inter-days RSDs between 8.97% and 16.49% (n = 9). The robot-assisted technique eased the control of dynamic SDME, making the process more feasible, robust, and reliable so that the developed setup demonstrated to be a competitive strategy for the automated extraction of organic pollutants from water samples.

Modern automated microextraction procedures for bioanalytical, environmental, and food analyses

“…The best extraction conditions were obtained with the use of large drops (90 μl) in the dynamic mode, with method RSD values < 9.3%, with LOQs between 35 and 100 ng/L. Later, in 2022, Bocelli et al [56] employed this system for automated SDME and analysis of parabens in wastewater by LC-MS/MS. With univariate and multivariate experiments, the authors investigated the main variables that affect SDME.…”

“…Later, in 2022, Bocelli et al. [56] employed this system for automated SDME and analysis of parabens in wastewater by LC‐MS/MS. With univariate and multivariate experiments, the authors investigated the main variables that affect SDME.…”

“…(B) Polytetrafluoroethylene (PTFE) adjustable needle endpoint drop‐expander. Reprinted [56] with permission (license number 5537250651582).…”

“…Moreover, open-source microcontrollers [48][49][50][51] currently facilitate the development of various automated sample preparation and analytical systems. Their applications including different robotic formats [52][53][54] and techniques, such as MEPS [55], SDME [56], HF-LPME [57,58], and DLLME [59] have been robotized employing lab-made systems.…”

The utilization of open‐source microcontroller boards and single‐board computers in liquid chromatography

“…Much of the research utilizing this system has focused on adapting various microextraction approaches to the automated sampler prior to online analysis. Some of the applications have included estrogen-like isoflavones in human urine [26], parabens in wastewater [27], sulfonamides and fluoroquinolones in surface water [28], and ring-substituted amphetamines in urine [29]. To further increase throughput for the analysis of cannabinoids in urine, six parallel syringes were mounted onto the platform for either simultaneous or independent operation of each channel [30].…”