GC-MS determination of parabens, triclosan and methyl triclosan in water by in situ derivatisation and stir-bar sorptive extraction

Abstract

Stir-bar sorptive extraction in combination with an in situ derivatisation reaction and thermal desorption-gas chromatography-mass spectrometry was successfully applied to determine parabens (methylparaben, isopropylparaben, n-propylparaben, butylparaben and benzylparaben), triclosan and methyltriclosan in water samples. This approach improves both the extraction efficiency and the sensitivity in the GC in a simple way since the derivatisation reaction occurs at the same time as the extraction procedure. The in situ derivatisation reaction was carried out with acetic anhydride under alkaline conditions. Thermal desorption parameters (cryofocusing temperature, desorption flow, desorption time, desorption temperature) were optimised using a Box-Behnken experimental design. All the analytes gave recoveries higher than 79%, except methylparaben (22%). The method afforded detection limits between 0.64 and 4.12 ng/L, with good reproducibility and accuracy values. The feasibility of the method for the determination of analytes in water samples was checked in tap water and untreated and treated wastewater.

Safe Drinking Water? Effect of Wastewater Inputs and Source Water Impairment and Implications for Water Reuse

“…Parabens have been found in surface waters at levels as high as 3,142 ng/L [66,67]. Methylparaben and propylparaben, which are the most commonly detected parabens in waters (in agreement with their extensive use in cosmetic formulations), have been quantified in tap water at levels up to 40 [68,69] and 135 ng/L [70], respectively. The main concerns regarding the presence of parabens in the environment arise from their endocrine disrupting potential and their possible involvement in the process of carcinogenesis, both of which are currently under investigation [67].…”

Analytical Methodologies for the Determination of Personal Care Products in Water Samples

“…Moreover, they found better results when using PDMS-DVB or DVB-CAR-PDMS fibers compared to PA fibers, but it should be taken into account that they extracted the acetylated derivatives instead of the more polar underivatized ones as in the other papers. As can be seen in Table 3, SBSE has been also extensively used in the determination of preservatives, exclusively [108,109,118,123] or together with other PCPs [45,56,68,80,96] in environmental waters. Due to the lack of commercially available sorbents, PDMS has been the most used one, but recently Gilart et al found that EGS exhibits better extraction efficiency than PDMS for triclosan and triclocarban [80].…”

“…Thus, it is common to perform a silylation [27,60,103,104,112,122,133], generally after the extraction is accomplished, or acetylation [96,106,116,117,120,123,129,132], generally during the extraction in order to increase both the extraction efficiency and volatility.…”

Gas chromatographic determination of parabens afterin-situderivatization and dispersive liquid-liquid microextraction

“…Acetylation with acetic anhydride is normally performed in the presence of hydrogencarbonate or pyridine [6,7]; however, according to the literature [7], the use of hydrogen phosphate leads to higher extraction efficiencies than the hydrogen carbonate. Thus, in our work, potassium hydrogenphosphate was used as a basic catalyzer.…”

“…Because of the wide use, parabens are continuously released into the environment [3,4]. The presence of parabens was determined in wastewater [5][6][7][8][9][10], swimming pool water [8,9,11], river water [7][8][9][10]12], and even in tap water [6].…”