Dilute-and-shoot approach for determination of several biomarkers and pharmaceuticals in wastewater using nanoflow liquid chromatography - Orbitrap mass spectrometry

A new method for quantitative analysis of several biomarkers and pharmaceutical compounds in wastewater has been developed employing nanoflow liquid chromatography with Orbitrap mass spectrometry. An easy dilute-and-shoot approach has been used for sample preparation with a dilution factor of 5. Improved retention of ionic and highly polar compounds has been achieved by the addition of tetrabutylammonium bromide as an ion pair reagent into the final diluted sample. The new nanoflow liquid chromatography method has demonstrated low matrix effects (70%-111%), high sensitivity in terms of limits of quantification (0.005 to 0.3 mu g/L), low injection volume (70 nl) and solvent consumption, and the ability to analyze diverse polar and ionic analytes within one run using a single reversed-phase nanoflow liquid chromatography column. Wastewater samples (n = 116) from the wastewater treatment plants of different cities in Latvia were analyzed using the developed method. The observed concentrations of biomarkers were in line with the literature data.

Automated summary

A new method using nanoflow liquid chromatography with Orbitrap mass spectrometry has been developed for quantitative analysis of biomarkers and pharmaceutical compounds in wastewater. The method employs an easy dilute-and-shoot approach for sample preparation and utilizes tetrabutylammonium bromide as an ion pair reagent to improve the retention of ionic and highly polar compounds. The new method demonstrates low matrix effects, high sensitivity, low injection volume and solvent consumption, and the ability to analyze diverse polar and ionic analytes within one run.