Determination of estrogenic compounds in milk and yogurt samples by hollow-fibre liquid-phase microextraction-gas chromatography-triple quadrupole mass spectrometry

• Published in: Analytical and bioanalytical chemistry Vol. 408; no. 26; pp. 7447 - 7459
• Main Authors: D’Orazio, Giovanni, Hernández-Borges, Javier, Herrera-Herrera, Antonio Vicente, Fanali, Salvatore, Rodríguez-Delgado, Miguel Ángel
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-10-2016; Springer; Springer Nature B.V
• Subjects: Acetonitrile; Analytical Chemistry; Animals; Biochemistry; Calibration; Cattle; Characterization and Evaluation of Materials; Chemical properties; Chemistry; Chemistry and Materials Science; Chromatography; Contamination; Dairy products; Estrogens; Estrogens - analysis; Estrogens - isolation & purification; Extraction; Extraction (Chemistry); Food; Food Analysis - methods; Food Contamination - analysis; Food Science; Food testing; Gas chromatography; Gas Chromatography-Mass Spectrometry - methods; Goats; Hormones; Laboratory Medicine; Limit of Detection; Liquid Phase Microextraction - methods; Mass spectrometry; Metabolites; Methods; Milk; Milk - chemistry; Monitoring/Environmental Analysis; Optimization; Reagents; Research Paper; Sample preparation; Scientific imaging; Yogurt; Yogurt - analysis; Spain; Tenerife; Gas chromatography-triple quadrupole mass spectrometry; Yogurt; Hollow-fibre liquid-phase microextraction; Estrogens; Milk
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-016-9833-0

An environmentally friendly method based on hollow-fibre liquid-phase microextraction (HF-LPME) was developed for the extraction of selected estrogenic compounds (i.e. four natural sexual hormones: estrone, 17β-estradiol, 17α-estradiol and estriol; two exoestrogens: 17α-ethynylestradiol and 2-methoxyestradiol; two synthetic stilbenes: dienestrol and hexestrol; and five resorcylic acid lactones: zearalenone, α-zearalanol, β-zearalanol, α-zearalenol and β-zearalenol), from whole cow and semi-skimmed goat milk and whole natural yogurt. After the optimization of the sample preparation procedure, spiked extracts were derivatized to their trimethylsilyl products using
N
,
O
-bis(trimethylsilyl)trifluoroacetamide reagent and then analyzed by gas chromatography–tandem mass spectrometry (GC-MS/MS). Once optimum extraction conditions were established (protein precipitation with acetonitrile, extraction and the back-extraction in acetonitrile following the HF-LPME procedure), the method was validated and the calibration range, precision and accuracy were studied. The RSD values for the intra- and inter-day precision of the peak areas were in the range 0.65–9.69 and 1.00–11.47 %, respectively. The determination coefficients were higher than 0.991 for method calibration curves while LOD and LOQ values were between 0.06–2.55 and 0.16–6.11 μg/L for whole cow milk, 0.04–1.70 and 0.11–4.86 μg/L for semi-skimmed goat milk and 0.07–3.73 and 0.23–9.81 μg/L for natural yogurt, respectively. Finally, the accuracy and precision of the method were evaluated, obtaining a value in the range 84 81–119 % and RSD values lower than 20 % in all cases.