Solid phase extraction cartridges

All chemicals were obtained from Sigma Aldrich unless stated otherwise. FVIIai was from Novo Nordisk A/S and was obtained by inactivation of FVIIa with phenylalanine-phenylalanine-arginine-chloromethyl ketone as previously described (16) . Gly-gly buffer consisted of 10 mM gly-gly, 150 mM NaCl, and 10 mM CaCl 2 , adjusted to pH 7.5. 4-(ethoxycarbonyl)-N,N,N-trimethylbenzenaminium triflate was purchased from ABX. Solidphase extraction cartridges were obtained from Waters. The PD-10 desalting column was obtained from GE Healthcare. All chemicals were used without further purification.

Methanol (MeOH) and formic acid (FA) were purchased from Fisher Scientific Inc (Pittsburgh, PA, USA). Trolox, ascorbic acid, quercetin, gallic acid and other standards were purchased from Sangon biological engineering co. LTD (Shanghai, China). Solid-phase extraction (C18) was purchased from Waters scientific Inc. LB Nutrient Agar was purchased from Beijing Aoboxing biotechnology co. LTD.
Escherichia coli, Staphylococcus aureus, and Bacillus subtilis were obtained from Institute of microbiology, Chinese Academy of Sciences, China. The solid phase extraction (SPE) cartridges were obtained from Waters (Milford, Mass, USA). All the cartridges contained 500 mg of C18.

Aqueous samples were filtered through 0.7 µm glass fibre filter paper (Millipore). In this study, isotopically labelled standards (50 ng for each compound) of 44 out of the 49 selected micropollutants were introduced into all samples for method recovery confirmation and quantification (Tran et al., 2016; Tran et al., 2013) . Isotopically labelled standards are not available for five micropollutants (i.e. oxybenzone, propylparaben, phenylphenol, sucralose and acesulfame) and they were quantified by external calibration. Aqueous samples (500 mL, pH ~ 7) were extracted onto hydrophilic/lipophilic balance (HLB) solid phase extraction (SPE) cartridges (500 mg 6 cc, Oasis, Waters, Milford, MA, USA). SPE cartridges were preconditioned with 90% v/v methyl-tertbutylether (MTBE) (5 mL), methanol (5 mL), then aliquots of Milli-Q grade water (2 x 5 mL). The samples were extracted onto the SPE cartridges through teflon lines at a flow rate of approximately 15 mL/min. The cartridges were gently dried under pure nitrogen for 30 minutes. Target micropollutants were eluted from the dried cartridges under gravity using methanol (2 x 3 mL) and MTBE (3 mL). The combined eluants were evaporated to approximately 1 mL under nitrogen using a Turbo-Vap (Caliper Life Sciences, Waltham, MA. USA) and transferred to a 2 mL amber autosampler vial for quantification.