Bisphenol and Phthalate Analysis Protocol

Methanol (MeOH), acetonitrile (MeCN), chloroform, dichloromethane, petroleum ether, and diethyl ether (HPLC-grade purity) were obtained from Macron Fine Chemicals (Barcelona, Spain), and acetic acid (99.9% purity) from J.T. Baker (Madrid, Spain). The analytical standards of bisphenol S (BPS, purity ≥ 98%), bisphenol F (BPF, purity ≥ 98%), bisphenol A (BPA, purity ≥ 99.9%), di(2-ethylhexyl) phthalate (DEHP, purity ≥ 99.5%), dibutyl phthalate (DBP, purity ≥ 99%), and diethyl phthalate (DEP, purity ≥ 99%) were obtained from Sigma Aldrich (Madrid, Spain). Individual standard stock solutions of the selected compounds were prepared in methanol and maintained in darkness at 4 °C until use. A concentration of 1000 mg/L was prepared for BPA, BPS, and phthalates (DEHP, DEP, and DBP), and a concentration of 100 mg/L for BPF. Daily working standard solutions were prepared by appropriate dilution with the mixture MeCN/water (85:15, v/v). A Milli-Q water system (Merck Millipore, Madrid, Spain) was used to obtain ultrapure water (18 MΩ/cm, 25 °C).
Florisil (60–100 mesh) from Acros Organics (Madrid, Spain), sodium sulfate anhydrous (Na₂SO₄, purity ≥ 99.9%), and washed sea sand (0.25–0.30 mm) from Panreac (Barcelona, Spain) were employed as sorbents for the sample extraction method. The silanized glass wool used was purchased by Panreac (Barcelona, Spain). Glass SPE cartridges (6 mL) used for packing the sorbent material were obtained from J.T. Baker (Deventer, The Netherlands). Evaporator/concentrator equipment (TECHNE, Long Branch, NJ, USA) was used to evaporate the samples.