Creatinine hydrochloride

Stock standard solutions containing the seven metabolites investigated (i.e., monoethyl phthalate (MEP); mono-benzyl phthalate (MBzP); mono-butyl phthalate (MBP); mono-cyclohexyl phthalate (MCHP); mono-2-ethylhexyl phthalate (MEHP); mono(3,5,5-trimethylhexyl) phthalate (MTMHP); and mono-n-octyl phthalate (MnOP) (100 mg/L in cyclohexane)) were supplied by Neochema GmbH (Germany). Working solutions for calibrations were prepared by serial dilution of the stock standard mixture with acetonitrile (Sigma-Aldrich, Darmstadt, Germany) Beta-glucuronidase from Escherichia coli (200 units/mL) was purchased from La Roche AG group. BSTFA (N,O-bis(trimethylsilyl)trifluoroacetamide) with 1% of TMCS (trimethylchlorosilane) was purchased from Sigma-Aldrich. Ammonium acetate (98%), calcium chloride (CaCl₂) (≥99%), creatinine hydrochloride (≥97%), ammonium phosphate dibasic (≥99%), magnesium chloride hexahydrate (≥99%), potassium chloride (≥99%), sodium sulfate (≥99%), urea (≥98%), acetone (99.9%), formic acid (≥95%), and methanol (99.9%) were purchased from Sigma-Aldrich. Nanopure water was provided by an ultrapure water system (Arium Pro, Sartorius, Göttingen, Germany).

Bisphenol A (≥99%), Bisphenol AF (≥99%), Bisphenol AP (≥99%), bisphenol B (≥98%), bisphenol BP (≥98%), bisphenol C (≥98%), bisphenol E (≥98%), bisphenol F (≥98%), bisphenol G (≥98%), bisphenol M (≥99%), bisphenol P (≥99%), bisphenol PH (≥99%), bisphenol S (≥98%), bisphenol TMC (≥97%), and bisphenol Z (≥99%) were purchased from Sigma-Aldrich. Stock standard solutions (100 mg/L) were individually prepared by dissolving standard compounds in acetonitrile. A stock standard mixture containing all the individual standards (100 mg/L) was also prepared and stored at −20 °C. Working solutions for calibrations were prepared by serial dilution of the stock standard mixture with acetonitrile (Sigma-Aldrich). Beta-glucuronidase from E. coli (200 units/mL) was purchased from La Roche AG group. Bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% of trimethylchlorosilane (TMCS) solution was used for BPs derivatization and was purchased from Sigma-Aldrich. Ammonium acetate (98%), calcium chloride (CaCl₂) (≥99%), creatinine hydrochloride (≥97%), ammonium phosphate dibasic (≥99%), magnesium chloride hexahydrate (≥99%), potassium chloride (≥99%), sodium sulphate (≥99%), urea (≥98%), acetone (99.9%), formic acid (≥95%), and methanol (99.9%) were purchased from Sigma-Aldrich. Nanopure water was provided by an ultrapure water system (ariumPro, Sartorius, Germany).