Liquid chromatography-time-of-flight high-resolution mass spectrometry study and determination of the dansylated products of estrogens and their hydroxylated metabolites in water and wastewater.

A method combining liquid chromatography with a dual-probe ultraspray electrospray ionization (ESI) source and time-of-flight high-resolution mass spectrometry (LC-ESI-TOF/MS) was developed for the simultaneous determination of four steroidal sex hormones, estrone (E1), 17β-estradiol (E2), 17α-ethinyl estradiol (EE2), and estriol (E3), as well as five of their hydroxylated metabolites, 2-hydroxyestrone (2-OHE1), 4-hydroxyestrone (4-OHE1), 16α-hydroxyestrone (16-OHE1), 2-hydroxyestradiol (2-OHE2), and 4-hydroxyestradiol (4-OHE2), in water samples in a short chromatographic run of 10 min. Derivatization of the analytes was optimized using dansyl chloride as the derivatizing agent. Under optimal positive ionization conditions, the following signals, which had not been previously reported, were observed (with theoretical values of m/z 377.

Ultra-high-performance liquid chromatography-Time-of-flight high resolution mass spectrometry to quantify acidic drugs in wastewater.

A novel analytical approach involving an improved rotating-disk sorptive extraction (RDSE) procedure and ultra-high-performance liquid chromatography (UHPLC) coupled to an ultraspray electrospray ionization source (UESI) and time-of-flight mass spectrometry (TOF/MS), in trap mode, was developed to identify and quantify four non-steroidal anti-inflammatory drugs (NSAIDs) (naproxen, ibuprofen, ketoprofen and diclofenac) and two anti-cholesterol drugs (ACDs) (clofibric acid and gemfibrozil) that are widely used and typically found in water samples. The method reduced the amount of both sample and reagents used and also the time required for the whole analysis, resulting in a reliable and green analytical strategy. The analytical eco-scale was calculated, showing that this methodology is an excellent green analysis, increasing its ecological worth.

Microextraction of non-steroidal anti-inflammatory drugs from waste water samples by rotating-disk sorptive extraction.

In this study, six non-steroidal anti-inflammatory drugs (NSAIDs) were extracted from water samples using the rotating-disk sorptive extraction (RDSE) technique. The extraction disk device contains a central cavity that allows for the incorporation of a powdered sorbent phase (Oasis™ HLB). The analytes were extracted from water and pre-concentrated on the sorbent to reach the extraction equilibrium, and then they were desorbed with solvent, derivatized and determined by gas chromatography-mass spectrometry (GC-MS).

Determination of crystal violet in water by direct solid phase spectrophotometry after rotating disk sorptive extraction.

The microextraction of crystal violet (CV) from water samples into polydimethylsiloxane (PDMS) using the rotating disk sorptive extraction (RDSE) technique was performed. The extracting device was a small Teflon disk that had an embedded miniature magnetic stirring bar and a PDMS (560 μL) film attached to one side of the disk using double-sided tape. The extraction involves a preconcentration of CV into the PDMS, where the analyte is then directly quantified using solid phase spectrophotometry at 600 nm.