Application of porous membrane protected micro-solid-phase-extraction combined with gas chromatography-mass spectrometry for the determination of estrogens in ovarian cyst fluid samples.

ABSTRACT

A cost effective and environmentally friendly extraction technique using porous membrane protected micro-solid phase extraction (µ-SPE) is described for the extraction of estrogens in cyst fluid samples obtained from cancer patients. A sorbent (ethylsilane (C2) modified silica) (20 mg) was packed in a porous polypropylene envelope (2 cm×1.5 cm) whose edges were heat sealed to secure the contents. The µ-SPE device was conditioned with acetone and placed in a stirred (15) diluted cyst fluid sample solution (10 mL) to extract estrogens for 60 min. After extraction, the analytes were desorbed and simultaneously derivatized with a 51 mixture of acetone and N,O-bis(trimethylsilyl)-trifluoroacetamide. The extract (2 µL) was analyzed by gas chromatography-mass spectrometry. Various extraction, desorption and derivatization conditions were optimized for µ-SPE. With this simple technique, low limits of detection of between 9 and 22 ng L(-1) and linear range from the detection limits up to 50 µg L(-1) were achieved. The optimized method was used to extract estrogens from cyst fluid samples obtained from patients with malignant and benign ovarian tumors.