Simultaneous determination of a suite of endogenous steroids by LC-APPI-MS: Application to the identification of endocrine disruptors in aquatic toxicology
Citation:
Blackwell, B. AND G. Ankley. Simultaneous determination of a suite of endogenous steroids by LC-APPI-MS: Application to the identification of endocrine disruptors in aquatic toxicology. Journal of Chromatography B. Elsevier Science Ltd, New York, NY, 1163:122513, (2021). https://doi.org/10.1016/j.jchromb.2020.122513
Impact/Purpose:
Endocrine-disrupting compounds (EDCs) can cause adverse effects in humans and wildlife. Small fish species are commonly used in toxicity testing to identify EDCs, but currently available methods for measurement of steroid hormones in fish are limited to a few steroids. The current study details an analytical method to measure 13 endogenous steroids using liquid chromatography-mass spectrometry (LC-MS). The validated method was applied to measure steroids in fish plasma and fish holding water. The study demonstrates the effectiveness of the method for identifying EDCs is aquatic toxicity studies and can be applied to identify EDCs interacting with a wide variety of molecular targets.
Description:
Exposure to endocrine-disrupting compounds (EDCs) can lead to perturbations of normal, steroid hormone production in vertebrates, ultimately leading to adverse reproductive or developmental effects. Liquid chromatography mass spectrometry (LC-MS) methods are the gold standard for analyte confirmation and quantification in biological matrices, but the use of radioimmunoassays (RIAs) is still common for measurement of select steroid hormones in aquatic toxicology studies. In the current study, a method was developed for the simultaneous measurement of thirteen endogenous steroids using liquid chromatography atmospheric pressure photoionization tandem mass spectrometry (LC-APPI-MS/MS). Steroids important to small fish steroidogenesis were selected for the analysis and included 11-deoxycortisol, 11-ketotestosterone, 17á- and 17â-estradiol, 17á-hydroxyprogesterone, 17,20â-dihydroxyprogesterone, 17,20â,21-trihydroxyprogesterone, androstenedione, cortisol, estriol, estrone, progesterone, and testosterone. The method was validated for application to small volumes of fish plasma and fish holding water. Method detection limits (MDL) using only 10µL of plasma ranged 0.05 1.0 ng/mL. As a potential surrogate for plasma steroid measurements, fish holding water was analyzed to measure excreted steroids. Lower limits of quantification (LLOQ) when using 0.25 L of holding water ranged 0.05 1.0 ng/L. The validated method was applied to two different experiments exposing small fish species to a known EDC, fadrozole, and measuring concentrations of the thirteen steroids in plasma or flow-through exposure water. This study demonstrates the potential application of the developed method to measurement of endogenous steroids for identification of EDCs in aquatic toxicology studies.
URLs/Downloads:
DOI: Simultaneous determination of a suite of endogenous steroids by LC-APPI-MS: Application to the identification of endocrine disruptors in aquatic toxicology