Effect of salinity and pH on the calibration of the extraction of pharmaceuticals from water by PASSIL.

High salinity and a relatively high pH are two factors characterizing the marine water environment, which is one of the main final reservoirs receiving pharmaceutical residues. The same factors have an undeniable impact on the extraction efficiency and kinetics of uptakes of polar analytes from water by sorbent-based passive sampling techniques. Recently, we presented a novel passive sampling technique, in which ionic liquids are applied as receiving phases for pharmaceutical monitoring in water (the Passive Sampling with Ionic Liquids technique). In this paper we test the impact of salinity and pH on the PASSIL calibration (sampling rate determination) and the extraction efficiencies of sulfonamides, beta-blockers and nonsteroidal anti-inflammatory drugs selected as model contaminants. Trihexyl(tetradecyl)phosphonium dicyanamide ([P666-14][N(CN)2]) was taken as the stable liquid receiving phase. It selectively extracted neutral and negatively charged analytes from donor solutions of different pH (1, 3, 7 and 9). The presence of salt (7, 20 and 35 PSU) decreased the efficiency (by 5-65%) and Rs (by 0.017Lday-1 to 0.574Lday-1) of PASSIL for all target compounds. The general conclusion is that salinity and pH have a significant impact on the calibration of passive dosimeters for ionizable compounds, both for the new PASSIL technique and standard POCIS techniques.

Ionic liquids for the passive sampling of sulfonamides from water-applicability and selectivity study.

Ionic liquids (ILs) are new-generation, non-volatile solvents which are designable, and their structure may be specifically adjusted to the current application needs. Therefore, it is possible to create and apply ILs which efficiently and selectively extract various analytes from different matrices. It has already been examined that ILs may be applied as receiving phases in passive sampling for the long-term water monitoring of PAHs and pharmaceuticals in water. In this paper, the concept of passive sampling with ILs (PASSIL applied as receiving phases) was continued and developed using phosphonium-, imidazolium-, and morpholinium-cation-based ILs. The target group of analytes was pharmaceuticals which represent one of the most common categories of water contaminants. Fourteen-day-long extractions using various ILs were performed in stirred conditions at a constant temperature (20 °C). The best extraction efficiency was achieved for trihexyl(tetradecyl)phosphonium dicyanamide ([P666-14][N(CN)2]). For this preliminary calibration, the sampling rates were calculated for each sulfonamide. Once again, selectivity was observed in passive sampling using [P666-14][N(CN)2]. Therefore, PASSIL is seen as a very promising method for pharmaceutical monitoring in water.

Calibration of Passive Samplers for the Monitoring of Pharmaceuticals in Water-Sampling Rate Variation.

Passive sampling is one of the most efficient methods of monitoring pharmaceuticals in environmental water. The reliability of the process relies on a correctly performed calibration experiment and a well-defined sampling rate (Rs) for target analytes. Therefore, in this review the state-of-the-art methods of passive sampler calibration for the most popular pharmaceuticals: antibiotics, hormones, ß-blockers and non-steroidal anti-inflammatory drugs (NSAIDs), along with the sampling rate variation, were presented. The advantages and difficulties in laboratory and field calibration were pointed out, according to the needs of control of the exact conditions. Sampling rate calculating equations and all the factors affecting the Rs value - temperature, flow, pH, salinity of the donor phase and biofouling - were discussed. Moreover, various calibration parameters gathered from the literature published in the last 16 years, including the device types, were tabled and compared. What is evident is that the sampling rate values for pharmaceuticals are impacted by several factors, whose influence is still unclear and unpredictable, while there is a big gap in experimental data. It appears that the calibration procedure needs to be improved, for example, there is a significant deficiency of PRCs (Performance Reference Compounds) for pharmaceuticals. One of the suggestions is to introduce correction factors for Rs values estimated in laboratory conditions.

Application of the PASSIL technique for the passive sampling of exemplary polar contaminants (pharmaceuticals and phenolic derivatives) from water.

Ionic liquids (ILs) are one of the very promising media for the passive sampling of organic contaminants in water. These compounds offer a wide range of interactions with various analytes and give possibilities to control analyte properties by altering their structures, but most of all, possess a high polarity independent of the water solubility. Recently, some ILs were successfully applied as the receiving phase in the passive sampling of polyaromatic hydrocarbons, and this approach was acronymized to PASSIL. In this paper, we aimed to verify the applicability of the PASSIL technique for the selective extraction and enrichment of polar and semi-polar compounds from aqueous environments. The test kit of analytes comprised selected pharmaceuticals and phenol-type compounds, while the applied ILs were alkylimidazolium- and alkylphosphonium entities with a variety of anions. The 14-day-long experiments were performed in static and semi-static no-renewal systems. The kinetics of the uptake process, the analyte extraction efficiency and the sampling rates for all analytes were determined. One of the tested ionic liquids [P666-14][N(CN)2] presented very promising properties both as a stable medium between polyethersulfone (PES) membranes as well as a highly effective extraction phase. The uptake kinetics of the analytes and the determined sampling rates confirm the better and faster efficiency of PASSIL extraction when compared to commercially available passive samplers. Additionally, some selectivity was observed during analyte extraction, which results from the specific interaction between the IL and analytes, but not from the lipophilicity or ionization state of the analytes. These very promising findings make the PASSIL approach a very promising and competitive analytical tool for the extraction of environmental contaminants over a wide polarity range.