Multi-residue analysis of pharmaceuticals in aqueous environmental samples by online solid-phase extraction–ultra-high-performance liquid chromatography-tandem mass spectrometry: Optimisation and matrix effects reduction by quick, easy, cheap, effective, rugged and safe extraction

• Published in: Journal of Chromatography A Vol. 1349; pp. 11 - 23
• Main Authors: Bourdat-Deschamps, Marjolaine, Leang, Sokha, Bernet, Nathalie, Daudin, Jean-Jacques, Nélieu, Sylvie
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 04.07.2014; Elsevier
• Subjects: Analytical chemistry; Animals; Anti-Bacterial Agents - analysis; Chemistry; Chemistry Techniques, Analytical - economics; Chromatographic methods and physical methods associated with chromatography; Chromatography, High Pressure Liquid; Cut-off; Dissolved organic carbon; Emerging pollutants; Environmental Monitoring - economics; Environmental Monitoring - methods; Exact sciences and technology; Extraction; Human and veterinary pharmaceuticals; Life Sciences; Mass spectrometry; New analysis method; Online; Online SPE–UHPLC-MS–MS; Other chromatographic methods; Pharmaceutical Preparations - analysis; Pharmaceuticals; Sample preparation; Sewage - chemistry; Slurries; Soil (material); Solid Phase Extraction - economics; Swine; Tandem Mass Spectrometry; Tetracyclines; Waste Water - chemistry; Water - chemistry; Dissolved organic carbon; New analysis method; Human and veterinary pharmaceuticals; Sample preparation; Online SPE–UHPLC-MS–MS; Emerging pollutants; Ultra performance liquid chromatography; Solid phase extraction; Tandem mass spectrometry; Chemical analysis; On line; Animal slurry; Supernatant; Solvent extraction; Multiresidue analysis; Sewage sludge; Electrospray; Optimization; Chemical enrichment; Aqueous medium; QuEChERS; Online SPE-UHPLC-MS-MS; Agricultural waste; Quantitative analysis; Trace analysis; Drug; Coupled method; Matrix effect; Soils; Analysis method; Emerging pollutant; Animal waste
• ISSN: 0021-9673; 1873-3778
• DOI: 10.1016/j.chroma.2014.05.006

•An optimised multi-residue method to quantify pharmaceuticals in aqueous samples.•Modified QuEChERS salts allow fluoroquinolones and tetracyclines to be analysed.•QuEChERS method lowers matrix effects in carbon rich samples.•A new method based on matrix effect reduction and isotopic dilution quantification.•Pharmaceuticals detected/quantified in soil water, sludge and slurry supernatants. The aim of this study was to develop and optimise an analytical method for the quantification of a bactericide and 13 pharmaceutical products, including 8 antibiotics (fluoroquinolones, tetracyclines, sulfonamides, macrolide), in various aqueous environmental samples: soil water and aqueous fractions of pig slurry, digested pig slurry and sewage sludge. The analysis was performed by online solid-phase extraction coupled to ultra-high performance liquid chromatography with tandem mass spectrometry (online SPE–UHPLC-MS–MS). The main challenge was to minimize the matrix effects observed in mass spectrometry, mostly due to ion suppression. They depended on the dissolved organic carbon (DOC) content and its origin, and ranged between −22% and +20% and between −38% and −93% of the signal obtained without matrix, in soil water and slurry supernatant, respectively. The very variable levels of these matrix effects suggested DOC content cut-offs above which sample purification was required. These cut-offs depended on compounds, with concentrations ranging from 30 to 290mgC/L for antibiotics (except tylosine) up to 600–6400mgC/L for the most apolar compounds. A modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) extraction procedure was therefore optimised using an experimental design methodology, in order to purify samples with high DOC contents. Its performance led to a compromise, allowing fluoroquinolone and tetracycline analysis. The QuEChERS extraction salts consisted therefore of sodium acetate, sodium sulfate instead of magnesium sulfate, and sodium ethylenediaminetetraacetate (EDTA) as a ligand of divalent cations. The modified QuEChERS procedure employed for the extraction of pharmaceuticals in slurry and digested slurry liquid phases reduced the matrix effects for almost all the compounds, with extraction recoveries generally above 75%. The performance characteristics of the method were evaluated in terms of linearity, intra-day and inter-day precision, accuracy and limits of quantification, which reached concentration ranges of 5–270ng/L in soil water and sludge supernatant, and 31–2400ng/L in slurry and digested slurry supernatants, depending on the compounds. The new method was then successfully applied for the determination of the target compounds in environmental samples.