Development of Methods for the Analysis of Polar Compounds in Environmental Matrices using LC/UV and LC/MS

Abstract: In recent years, the awareness of environmentally hazardous compounds with polar and ionizable properties has intensified. Pharmaceuticals, the pesticide tebuconazole as well as the artificial sweetener sucralose are examples of such new, emerging, contaminants. The toxicological and ecotoxicological effects of these contaminants require investigation. This has led to an increasing need for analytical methods capable of measuring polar compounds in environmental matrices. This thesis describes the use of liquid chromatography (LC) hyphenated with ultraviolet (UV) or mass spectrometric (MS) detection for four environmental applications. Paper I describes a method for the detection and qualitative analysis of hydroxyalkyl cobalamins using LC/MS. The method was part of a project for the determination of carcinogenic compounds bound as adducts to the DNA molecule. In paper II, a LC/UV method for the analysis of the pesticide tebuconazole was developed. The method was used to evaluate a novel ecotoxicological test system. Paper III describes an LC/MS method for the determination of the artificial sweetener sucralose in sewage and recipient water. The sucralose molecule and its fragments were found difficult to detect, and a method was developed as an alternative to multiple reaction monitoring (MRM). Both quadrupoles scanned the same ion, a novel technique hypothesized to reduce matrix effects compared to selected ion recording (SIR). Paper IV describes a method for the extraction and analysis of pharmaceuticals in sediment. The study emphasizes the evaluation of suitable solvents for the extraction of basic, neutral and acidic pharmaceuticals. It was concluded that an extraction solvent containing acetone : McIlvaine buffer (pH 4) was appropriate. Electrospray LC/MS in the MRM mode was used. Additional qualitative identification of non target pharmaceuticals was performed by accurate mass measurements utilizing a quadrupole time-of-flight (Q/TOF) instrument.