Tsq quantiva triple

Following termination of
the experiments, concentrations of CBZ and the bioTPs CBZ-Ep and CBZ-DH
were quantified by diluting the exposure medium with MeOH containing
an internal standard (IS) and then analyzing the diluted medium by
liquid chromatography tandem mass spectrometry (LC–MS/MS) using
an Ultimate 3000 ultrahigh-performance liquid chromatograph (UHPLC;
Thermo, USA) coupled to a TSQ Quantiva triple quadrupole mass spectrometer
(Thermo, USA) as described previously.^{21 (link)} Further details are provided in the Supporting Information. Measured CBZ doses following exposure were 43,367,
4854, 445, 41, 3.85, and 0.46 μg/L, with RSDs ranging from 4–12%
(see Table S2), which are within 77–97%
of the nominal. The increasing amount of dilution required to measure
CBZ in successively higher doses resulted in the intermittent quantification
of only CBZ-Ep (in the 43,367 and 445 μg/L doses) despite the
fact that CBZ-Ep and CBZ-DH were above detection limit in most doses
(following exposure).

10μl samples were injectd in triplicate into a Thermo Scientific Ultimate 3000 HPLC system on a SeQuant ZIC-cHILIC column (2.1 × 100 mm, 3 μm) with a ZIC-cHILIC guard column (2.1 × 20 mm, 5 μm), coupled with a Thermo Scientific TSQ Quantiva triple quadrupole mass spectrometer. The mobile phase was water with 0.1% formic acid (A) and acetonitrile (B), and the elution program was as follows: 0 min 25% A, 0.5 min 25% A, 4.5 min 45% A, 5.0 min 70% A, 8.0 min 70% A, 8.1 min 25% A, 12.0 min 25% A at 0.2 mL/min. Ionization was operated in the positive mode with the voltage of 4.2 kV. The parameters were set as follow: sheath gas, 35 Arb, aux gas, 15 Arb, vaporizer temperature, 250 °C, ion transfer tube temperature, 325 °C. Multiple reaction monitoring (MRM) was performed using a cycle time of 0.3 s, CID gas pressure of 1.5 mTorr, Q1 resolution (FWHM) of 0.7 and Q3 resolution (FWHM) of 0.7. The MRM transitions 104.1>87 (GABA), 108.1>91 (¹³C₄-GABA), 154.1>91 (dopamine) and 157.1>93 (²H₃dopamine) were selected for quantification. All data was integrated and processed in Xcalibur (Version 2.2, Thermo Scientific).

10μl samples were injectd in triplicate into a Thermo Scientific Ultimate 3000 HPLC system on a SeQuant ZIC-cHILIC column (2.1 × 100 mm, 3 μm) with a ZIC-cHILIC guard column (2.1 × 20 mm, 5 μm), coupled with a Thermo Scientific TSQ Quantiva triple quadrupole mass spectrometer. The mobile phase was water with 0.1% formic acid (A) and acetonitrile (B), and the elution program was as follows: 0 min 25% A, 0.5 min 25% A, 4.5 min 45% A, 5.0 min 70% A, 8.0 min 70% A, 8.1 min 25% A, 12.0 min 25% A at 0.2 mL/min. Ionization was operated in the positive mode with the voltage of 4.2 kV. The parameters were set as follow: sheath gas, 35 Arb, aux gas, 15 Arb, vaporizer temperature, 250 °C, ion transfer tube temperature, 325 °C. Multiple reaction monitoring (MRM) was performed using a cycle time of 0.3 s, CID gas pressure of 1.5 mTorr, Q1 resolution (FWHM) of 0.7 and Q3 resolution (FWHM) of 0.7. The MRM transitions 104.1>87 (GABA), 108.1>91 (¹³C₄-GABA), 154.1>91 (dopamine) and 157.1>93 (²H₃-dopamine) were selected for quantification. All data was integrated and processed in Xcalibur (Version 2.2, Thermo Scientific).