## 1 Introduction  
Endocrine-disrupting chemicals (EDCs) are a group of chemicals or mixtures of chemicals in the environment (air, soil, or water supply), food sources, personal care products, and manufactured products that exert hormonal-mimicking effects and interfere with the hormonal regulatory mechanisms of living organisms. The occurrence of EDCs in wastewater, which is released into aquatic environments, is of particular concern because of their potential impact of wildlife as their persistence in water supplies for humans. A variety of methods have been used for targeted analyses of endocrine-disrupting chemicals (EDCs) in surface and wastewater, and often focus on selective groups or a limited target list of EDCs to address the need to optimize the separation and mass spectrometric detection (MS), and to ensure stability and good recoveries of the EDCs in sample preparation procedures. Often estrogenic EDCs are analyzed separately from non-estrogenic EDCs [1; 2; 3; 4; 5; 6; 7], and most existing methods can meet detection limits required for monitoring requirements but are designed for specific sample matrices. Selective estrogenic EDCs are included in the watch list for the European Union and the United States Environmental Protection Agency [8; 9]. This work focuses on natural estrogens (17\(\beta\)-estradiol, estrone, and estriol), synthetic estrogens (17\(\alpha\)-ethinylestradiol, and diethylstilbestrol (not prescribed since 1971 in Canada and United States and was previously prescribed to prevent miscarriage and premature delivery)), xenostrogens (bisphenol A, 4-octylphenol, and 4-nonylphenol), and two glucocorticoid drugs (prednisolone and prednisone) that are not routinely analyzed. Natural estrogens enter wastewater from domestic and agricultural discharge, while synthetic estrogens and glucocorticoid drugs are prescribed to patients with human excretion as the main source entering wastewater [4; 10; 11; 12; 13; 14; 15; 16]. Prednisone and prednisolone are prescribed to patients within Saskatchewan in both hospital and outpatient settings for a variety of health issues, including arthritis, dermatologic, ophthalmic, respiratory, and gastrointestinal diseases, and cancer treatments [5]. Prednisolone is the metabolite or degradation product of prednisone and is preferred for patients with impaired liver function. Bisphenol A is used in the manufacturing of plastics, rubber, and flame retardants and is released from plastic and polycarbonate materials into wastewater and surface water [10]. Alkylphenols are used as surfactants, plastic additives, and emulsifiers, and major sources include discharge during the manufacturing of plastics and the use of detergents [12; 17; 18; 19; 20; 21; 22; 23]. These analytes that are EDCs are typically not included in multiresidue analysis methods due to specialized needs in sample preparation or separation-mass spectrometric detection. Due to the high complexity of the wastewater matrix, a number of alternative methods have been used for analysis of estrogenic and xenoestrogenic compounds. Gas chromatography methods without derivatization have been used for bisphenol A (BPA), octylphenol, and nonylphenol in surface and wastewater with recoveries ranging from 88-112% and 111-129%, respectively [24; 25]. To improve MS sensitivity or peak shape in the separation for these more polar analytes as well as estrone (E1), 17\(\beta\)-estradiol (E2), and 17\(\alpha\)-ethinylestradiol (EE), silylation prior to analysis has also been used to produce stable trimethylsilyl or tert-butyldimethylsilyl derivatives with recoveries in the range of 70-120% [26]. However, recoveries achieved for analytes can vary with conditions used in the derivatization, including the presence of matrix, leading to greater challenges in selecting suitable methods for wastewater [27]. More commonly now, liquid chromatography-mass spectrometry is selected to avoid the need to derivatize estrogens or xenoestrogens.