Pressurized liquid extraction followed by liquid chromatography with tandem mass spectrometry to determine pharmaceuticals in mussels.

An analytical method based on pressurized liquid extraction and solid-phase extraction with a mixed-mode Oasis(®) MAX sorbent as cleanup, followed by liquid chromatography with electrospray ionization and tandem mass spectrometry was developed and validated for the determination of seven widely used pharmaceuticals in mussel species. The optimization of the pressurized liquid extraction and the solid-phase extraction parameters is described. The method provided extraction recoveries ranging from 61 to 90%, and limits of detection ranging from 2 to 50 ng/g (dry weight). The repeatability and reproducibility of the method, expressed as relative standard deviation, were lower than 15 and 19%, respectively. The method was successfully applied to the analysis of mussel samples from different locations. The analyses showed that salicylic acid was present in mussels at concentrations up to 177 ng/g (dry weight).

Determination of pharmaceuticals in bivalves using QuEChERS extraction and liquid chromatography-tandem mass spectrometry.

A method for the quantitative determination of seven pharmaceuticals in bivalves was developed by QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with electrospray ionization. Both the European Standard Method EN 15662 and the AOAC Official Method 2007.01 for QuEChERS were tested. In addition, several clean-up strategies were evaluated in order to clean the matrix previous to the LC-MS/MS analyses. Dispersive solid-phase extraction with silica gel and modification of the chromatographic separation were the clean-up strategies that gave the best results. The optimized method was validated in mussels (Mytilus galloprovincialis) and allowed the determination of pharmaceuticals at nanograms per gram levels (dry weight (d.w.)). Limits of quantification ranged from 5 to 100 ng/g. Apparent recoveries ranged from 35 to 77%. The application of this method to bivalves revealed the presence of salicylic acid at concentrations up to 103 ng/g (d.w.).

Multiresidue analytical method for high production volume chemicals in dust samples, occurrence and human exposure assessment.

A multiresidue analytical method based on pressurised liquid extraction and gas-chromatography mass spectrometry was developed to determine 22 compounds belonging to different chemical families in indoor dust.: Seven organophosphate esters, six phthalate esters, three benzotriazoles, five benzothiazoles and four benzenesulfonamides were included in the present study, all of them belonging to the category of high production volume chemicals (HPVCs). Apparent recoveries ranged between 45% and 123% and method quantification limits ranged from 0.03 µg/g to 3.8 µg/g. The occurrence of the selected HPVCs was evaluated in indoor dust from different locations in the Tarragona (Catalonia, Spain) region. Two benzenesulfonamides, ortho-toluenesulfonamide and para-toluenesulfonamide, were detected in dust samples for the first time. Phthalate esters and organophosphate esters were the most abundant compounds found, and di-(2-ethylhexyl) phthalate (DEHP) was determined at the highest concentrations. With the data obtained, human exposure was assessed by calculating the estimated daily intakes (EDI) via ingestion and dermal contact. Non-carcinogenic and carcinogenic risk assessments found no risks in any of the scenarios tested, which included two age classes (children and adults) and two possible exposure scenarios (median and worst-case scenario), except for the evaluation of carcinogen risk due to ingestion of DEHP in the worst-case scenario.

Pressurised liquid extraction and liquid chromatography-high resolution mass spectrometry to determine high-intensity sweeteners in fish samples.

An analytical method based on pressurised liquid extraction (PLE) followed by liquid chromatography-high resolution mass spectrometry (Orbitrap) was developed for the simultaneous determination of ten high-intensity sweeteners in fish samples. As the method was developed, the different PLE parameters were optimised and different clean-up strategies were evaluated, of which in-cell clean-up using alumina and on-cell clean-up with hexane were the most effective. PLE recoveries were between 43% and 94%. The method quantification limits were between 12.5ngg-1 dry weight (d.w.) and 250ngg-1 (d.w.) and the method detection limits between 2.5ngg-1 (d.w.) and 125ngg-1 (d.w.). Intra-day precision and inter-day precision were below 16% and 25%, respectively. Fish samples from different species were analysed and, saccharin was found below its method quantification limit in the species Scomber scombrus (Atlantic mackerel).

Different sample treatments for the determination of ICM-XR in fish samples followed by LC-HRMS.

Iodinated X-ray contrast media (ICM-XR) are a group of pharmaceuticals widely used in medicine. Due to their low biodegradation rate, which makes their removal at wastewater treatment plants difficult, and the high doses at which they are administered, they have been detected in aquatic environments. In the present paper, a method for the quantitative determination of a group of ICM-XR in different fish species was developed and validated for the first time. Two extraction techniques were compared: pressurised liquid extraction (PLE) and QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe), with PLE being selected, followed by liquid chromatography-high resolution mass spectrometry. In addition, several clean-up strategies were evaluated. The optimised method provided PLE recoveries ranging from 60% to 88% and limits of detection ranging from 5ng/g to 25ng/g (dry weight). The method was applied in order to evaluate the presence of the selected ICM-XR in different fish species.