Aplicação de Cromatografia Gasosa acoplada à Espectrometria de Massa sequencial (CG-MS/MS) na determinação de disruptores endócrinos em matrizes ambientais

Abstract

Endocrine disruptors (EDs) are exogenous agents that interfere with hormonal functions, affecting the development, growth and reproduction of living beings, such as reduced egg hatching and feminization of male fish. These compounds, whether natural or synthetic, are persistent and widely dispersed in the environment. Such characteristics make it essential to develop analytical methods capable of reliably quantifying them. However, the extremely low concentrations at which they are found make detection challenging, thereby requiring the use of advanced instrumental techniques that provide greater sensitivity and precision. In this context, the present study aims to apply Gas Chromatography coupled with Tandem Mass Spectrometry (GC-MS/MS) for the determination of endocrine disruptors, validate this instrumental method, and apply it to sediment samples. Twelve ED-related compounds were analyzed: 5α-Androstan-3β-ol, Diethylstilbestrol (DES), Dienestrol (DNS), 17α Methyltestosterone (MET), Estrone (E1), 17α-Ethinylestradiol (EE2), Trenbolone (TB), Mestranol (MeEE2), Oxandrolone (OXA), Ethisterone, Coprostan-3-ol (Cop), and Megestrol (MGA), with the aid of the derivatizing agent BSTFA/TMCS (N,O-bis(trimethylsilyl)trifluoroacetamide/Trimethylchlorosilane), which enabled chromatographic analysis. For the GC-MS/MS analyses, variations in CID (Collision-Induced Dissociation) voltage and excitation energy (low, medium, high), with the precursor ion window fixed at 1, were studied to optimize the fragmentation parameters. Calibration standard solutions were prepared in acetonitrile to achieve a concentration range of 0.5 to 50.0 μg/mL, using internal standardization. Regarding the performance parameters selected for method validation, correlation coefficients for linearity were all above 0.99, ranging from 0.9907 to 0.9997. Limits of detection (LOD) ranged from 0.01 to 0.31 μg/mL, while limits of quantification (LOQ) ranged from 0.11 to 0.83 μg/mL. For precision, the relative standard deviation (RSD%) did not exceed the threshold established by INMETRO (National Institute of Metrology, Quality and Technology), with RSD% < 7.3% for the three concentration levels (low, medium, and high) of each calibration curve. Recovery rates were within the acceptable range of 80–110%. After application to sediment samples, the results demonstrated that this method is valid for the determination of endocrine disruptors in sediment matrices.