Determination of phenols and pharmaceuticals in municipal wastewaters from Polish treatment plants by ultrasound-assisted emulsification–microextraction followed by GC–MS

Abstract

A method combining ultrasound-assisted emulsification–microextraction (USAEME) with gas chromatography–mass spectrometry (GC–MS) was developed for simultaneous determination of four acidic pharmaceuticals, ibuprofen, naproxen, ketoprofen, and diclofenac, as well as four phenols, 4-octylphenol, 4-n-nonylphenol, bisphenol A, and triclosan in municipal wastewaters. Conditions of extraction and simultaneous derivatization were optimized with respect to such aspects as type and volume of extraction solvent, volume of derivatization reagent, kind and amount of buffering salt, location of the test tube in the ultrasonic bath, and extraction time. The average correlation coefficient of the calibration curves was 0.9946. The LOD/(LOQ) values in influent and effluent wastewater were in the range of 0.002–0.121/(0.005–0.403) μg L−1 and 0.002–0.828/(0.006–2.758) μg L−1, respectively. Quantitative recoveries (≥94 %) and satisfactory precision (average RSD 8.2 %) were obtained. The optimized USAEME/GC–MS method was applied for determination of the considered pharmaceuticals and phenols in influents and treated effluents from nine Polish municipal wastewater treatment plants. The average concentration of acidic pharmaceuticals in influent and effluent wastewater were in the range of 0.06–551.96 μg L−1 and 0.01–22.61 μg L−1, respectively, while for phenols were in the range of 0.03–102.54 μg L−1 and 0.02–10.84 μg L−1, respectively. The removal efficiencies of the target compounds during purification process were between 84 and 99 %.

Pharmaceutical pollution of aquatic environment: an emerging and enormous challenge

“…A number of APIs have been detected in the influents and effluents of wastewater treatment plants with the greatest survival rate displayed by carbamazepine (concentrations up to 5128 ng dm ) and naproxen (up to 117,000 ng dm -3 ) which reflects the popularity of these non-steroidal anti-inflammatory drugs in Poland (Kotowska et al 2014). All in all, these findings unsurprisingly indicate that treated wastewater is an important route for the introduction of various xenobiotic pharmaceuticals to surface and groundwater.…”

Quantitative mass spectrometry methods for pharmaceutical analysis

“…Because pharmaceuticals are in general polar, non-volatile molecules, derivatization reactions are required to make them suitable for GC analysis. To simplify and make this laborious process less time consuming, derivatization is sometimes conducted simultaneous with the sample preparation [81]. In order to enable multi-residue analysis, Kumirska et al [84] introduced a derivatization approach, which allows the simultaneous analysis of pharmaceuticals from six different drug classes in the nanogram per litre range.…”

Ultrasound-assisted extraction of emerging contaminants from environmental samples

“…Kotowska et al [21] reported an USAEME method for the simultaneous determination of four phenols and four pharmaceutical compounds in wastewater from a Polish WWTP. In this work, five different solvents were examined: three with density higher than water (i.e., 1,2-dichlorobenzene, carbon tetrachloride and chloroform) and two lighter than water (i.e., n-decane and toluene).…”

“…With in-situ derivatization, the reaction is performed simultaneously with the extraction procedure at very mild conditions and in a very short time. The derivatization reagent {i.e., acetic anhydride [21] or methyl chloroformate [22]} is added together with the extraction solvent before the emulsification step.…”