This application describes the development of a liquid chromatography/tandem mass spectrometry (LC-MS/MS) method for the determination of estrone-3-sulfate (E1S) in water with a sensitivity below the ppt level (< ng L-1). The method involves solid-phase extraction (SPE) and liquid chromatography/tandem mass spectrometry (LC-MS/MS) in negative electrospray mode. The method achieved high recoveries (>93%) and low detection limits (<1 pg L-1). In addition, the method was highly selective, with no interferences from other compounds observed. This makes it a suitable method for the analysis of E1S in environmental water samples.
This document details an analytical method for quantifying estrone-3-sulfate (E1S) in water samples at ultra-trace levels (sub-ppt). The method utilizes solid phase extraction (SPE) for sample preparation followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in negative electrospray mode.
The analysis is performed using an Agilent 1200 Infinity LC system coupled with an Agilent 6410 Triple Quadrupole Mass Spectrometer. The method employs a Gemini C18 column and monitors specific MRM transitions for both the analyte and an internal standard (boldenone-sulfate-d3) to ensure high specificity and sensitivity.
| Column | Gemini (50 mm x 2 mm, 3 µm) C18 110A |
|---|---|
| Column temperature | 40°C |
| Flow rate | 0.3 mL/min |
| Capillary voltage | 3500 V |
| Nebulizer pressure | 40 psi |
| Drying gas flow | 13 L/min |
| Gas temperature | 275°C |
| Injected volume | 10 µL |
The method analyzes estrone-3-sulfate down to sub-ppt level, specifically below 1 ng/L.
The method uses boldenone-sulfate-d3 as the internal standard.
The method monitors transitions at 349.2 > 269.2 and 349.2 > 146.2.