Determination of pharmaceutical residues in waters by solid-phase extraction and large-volume on-line derivatization with gas chromatography–mass spectrometry

• Published in: Journal of Chromatography A Vol. 1065; no. 2; pp. 279 - 285
• Main Authors: Lin, Wan-Ching, Chen, Hsin-Chang, Ding, Wang-Hsien
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 18.02.2005; Elsevier
• Subjects: Analysis methods; Analytical chemistry; Applied sciences; Chemistry; Chromatographic methods and physical methods associated with chromatography; Drug Residues - analysis; Exact sciences and technology; Gas chromatographic methods; Gas Chromatography-Mass Spectrometry - methods; GC-MS; Large-volume injection; Natural water pollution; Other wastewaters; Pharmaceuticals; Pollution; Reproducibility of Results; Sensitivity and Specificity; SPE; Wastewaters; Water Pollutants, Chemical - analysis; Water samples; Water treatment and pollution; GC-MS; Large-volume injection; SPE; Water samples; Pharmaceuticals; Solid phase extraction; Chemical analysis; Anticonvulsant; Derivatization; Ketoprofen; Diclofenac; Waste water; Chemical enrichment; Sample preparation; Clofibric acid; Naproxen; Ibuprofen; Quantitative analysis; Trace analysis; Validation; Fibrate derivatives; Coupled method; Tricyclic compound; Carbamazepine; Esterification; Non steroidal antiinflammatory agent; Gas chromatography; girds: Pharmaceuticals; Water pollution; River water; Mass spectrometry; Antilipemic agent
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2004.12.081

This work presents a modified method to analyze selected pharmaceutical residues (clofibric acid, ibuprofen, carbamazepine, naproxen, ketoprofen and diclofenac) in water samples. Various solid-phase extraction cartridges were investigated. The newly developed Oasis HLB (polystyrene-divinylbenzene- N-vinyl pyrrolidone terpolymer) solid-phase extraction (SPE) cartridge provides the optimal sample extraction results. The analytes were then identified and quantitatively determined by gas chromatography–mass spectrometry (GC–MS) via on-line derivatization in the injection-port using a large-volume (10 μl) sample injection with tetrabutylammonium (TBA) salts. This injection-port derivatization technique provides sensitivity, fast and reproducible results for pharmaceutical residues analysis. Mass spectra of butylated derivatives and tentative fragmentation profiles are proposed. Molecular ions and some characteristic ions were used as the quantitation ions to obtain maximum detection sensitivity and specificity. The quantitation limits of these compounds ranged from 1.0 to 8.0 ng/l in 500 ml tap water samples. Recovery of these residues in spiked various water samples ranged from 50 to 108% while RSD ranged from 1 to 10%. The selected analytes were detected in concentrations of 30 to 420 ng/l in wastewater treatment plant effluent and river water samples.