Determination of 2-methoxyestradiol from endometrial cancer patients' urine by LC-MS/MS with hollow fiber liquid-phase microextraction

Abstract

2-Methoxyestradiol (2-MeOE₂) is a potent antiangiogenic and antitumor agent in preclinical models due to its antiproliferative and apoptotic actions. In endometrial cancer patients' urine, the content of 2-MeOE₂ may be less than that in urine samples of healthy people. The sensitivity can be elevated to a high level by using hollow fiber liquid-phase microextraction (HF-LPME) as an enriched pretreatment method with LC-MS/MS as a detection means. In the experimental section, the urine sample was firstly handled with sodium hydroxide for hydrolysis and then extracted with HF-LPME. After that the extracts were derivatised and finally detected with LC-MS/MS. For HF-LPME, we obtained an enrichment factor of 180 along with a good sample clean-up. The calibration curve was linear with a linear regression correlation coefficient typically greater than 0.996. The limit of detection (LOD) for 2-MeOE₂ was 0.14 pg mL⁻¹ with good repeatability and reproducibility. The proposed method was applied for the analysis of human urine samples from endometrial cancer patients and healthy people.