1200 series liquid chromatography

The analysis of TBBPA and HBCDs was performed on an Agilent 1200 series liquid chromatography (LC) system coupled to an Agilent 6410 electrospray triple quadrupole mass spectrometer. A XDB-C₁₈ column (50 mm × 4.6 mm i.d., 1.8 μm, Agilent, CA) was used for TBBPA and HBCD diastereoisomer separation. A Phenomenex Nucleosil β-PM chiral LC column (200 mm × 4.0 mm i.d., 5 μm, Macherey-Nagel, GmbH & Co., Germany) was used for the HBCD enantiomer separation. Details of the analytical methodology used for separation and quantification of TBBPA and HBCD analysis were published previously (Feng et al. 2012 (link)).
Chiral HBCD compositions were expressed as enantiomeric fraction (EF), which is determined from the ratio of (+) enantiomer area over the sum peak areas of the (+) and (−) enantiomers corrected by areas of the corresponding d₁₈-labeled diastereoisomer standards (Marvin et al. 2007 (link)).

The liquid chromatography-mass spectrometry (LC-MS) analysis was performed in an Agilent 1200 series liquid chromatography coupled with Agilent 6410 triple quadrupole mass spectrometer [25 (link), 26 (link)]. Liquid chromatography separation was performed on an Agilent Eclipse plus C18 (2.1 × 100 mm × 3.5 μm) column. The flow rate was set at 0.4 ml/min, and the mobile phase consisted of (A) water+0.1% formic acid and (B) methanol+0.1% formic acid. The gradient programs were as follows: 0.0-1.0 min 10% B, 1.0-40 min from 10% to 100% (B), 40.0-42.0 min 100% (B), and 42.0-50 min from 100% to 10% (B). The mass spectra were acquired from 100 to 1000 within 50 minutes of scan time. The positive electrospray ionisation (ESI) mode was applied for the mass spectrometer. Mass feature extraction of the acquired LC-MS data and maximum detection of peaks was done using the MZmine analysis software package, version 2.3.

Liquid chromatography was performed on a Agilent 1200 series liquid chromatography (Germany). The separation was carried on a Agilent ZORBAX Eclipse Plus C18 column (3.0 × 150 mm, 5 μm) protected with a Zorbax-SB C18 guard column maintained at room temperature. The mobile phase composition was 75% of methanol (with 0.1% formic acid) and 25% of water (with 0.1% formic acid) in isocratic mode at a flow rate of 0.5 ml/min. The injection volume was 10 μl. An Agilent 6400 series triple quadrupole mass spectrometer equipped with Turbo Ion Spray interface operating in the positive electrospray ionization (ESI) mode was used for the detection. Operating conditions optimized by Mass Hunter optimizer for DHT and IS were: dry gas temperature 350°C; nebulizer pressure 35 psi; nitrogen gas flow rate 10 ml/min; capillary voltage 4,000 V and fragmentor voltage 130 V for DHT and 140 V for IS. Product ions (of DHT) resulting from transition of 291.2 → 255.2 (collision energy 12 eV) and product ions (of IS) 305.2 → 93.1 (collision energy 36 eV) were monitored at retention time of 5.5 min (for DHT) and 6.3 min (for IS).