Estrone direct photolysis: by-product identification using LC-Q-TOF

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Mass Spectrometry

Background:

• Estrone (E1) is a natural estrogenic hormone.
• Photodegradation is a significant environmental fate process for pharmaceuticals and hormones.
• Understanding E1 photodegradation is crucial for assessing its environmental risk.

Purpose of the Study:

• To identify and elucidate the structures of estrone (E1) degradation products formed under simulated UV irradiation.
• To investigate the photodegradation pathways of E1.
• To assess the potential environmental risk of E1 photoproducts.

Main Methods:

• Liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-Q-TOF MS).
• Use of model molecules (5,6,7,8-tetrahydro-2-naphtol [THN], 2-methylcyclopentanone [MCP]) and a labeled molecule (estrone D(4) [E1-D(4)]).
• Collision-induced dissociation (CID) and exact mass measurements.

Main Results:

• Identification of nine major E1 by-products, including seven photoproducts with modifications.
• Predominant formation of hydroxylated E1 derivatives, with one to three additional hydroxylations on the aromatic ring.
• Confirmation of structural modifications induced by photodegradation.

Conclusions:

• The study successfully identified key estrone photodegradation products.
• Hydroxylated estrone derivatives suggest potential environmental risks.
• The methodology is applicable to real environmental water samples.