Agilent 6430 triple quadrupole lc ms ms system

Memantine in each sample was determined by an Agilent 6430 Triple Quadrupole LC-MS/MS system (Agilent, Wilmington, DE, USA). The isocratic mobile phase consisting a mixture of water and methanol (15:85, v/v) containing 0.1% formic acid was used at a flow rate of 0.20 mL/min to elute memantine and propranolol peak from the rat plasma matrix. The separation was performed on a Polar RP column (150 × 4.6 mm, 5 μm particle size; Pheonomenex, Torrance, CA, USA).
Mass transition was monitored using multiple reaction monitoring (MRM) mode at m/z 180.1 → 163.1 for memantine and m/z 260.0 → 116.0 for propranolol (internal standard, IS) in positive ion mode with a collision energy of 10–15 eV. The analytical data were quantified using mass Hunter (version B.06.00, Agilent, Wilmington, DE, USA).

Agilent 6430 Triple Quadrupole LC/MS/MS system (Agilent Technologies, CA, USA) was employed for the analysis. For analysis of P3V8, chromatographic separation was achieved on a SunFire C8 Column (250 mm × 4.6 mm, 5 µm). The mobile phase of water containing 0.2% formic acid (A) and acetonitrile (B) was used with a gradient elution (0–5 min, 20–70% B). The flow rate was 0.8 mL/min. Multiple reactions monitoring (MRM) with fragmentation transition of 500 to 129 in positive ion mode was employed for quantization of P3V8. For analysis of L1P3V8, Alltima Amino Alltech Column (250 mm × 4.6 mm, 5 µm) was used for separation. Mobile phase of water (A) and acetonitrile (B) was used. The gradient elution for plasma samples was 0–4 min, 30–95% B, and for brain samples was 0–9 min, 10–95% B. The flow rate was 0.8 mL/min. MRM transition of 565 to 88 in positive ion mode was used for quantization of L1P3V8.

The analysis of the silybin concentration was performed using an Agilent 6430 triple quadrupole LC/MS-MS system (Agilent, Wilmington, DE, USA) coupled to an Agilent 1290 HPLC system according to the previous method with slight modification [41 (link)]. Silybin and naringenin (IS) was separated on Synergi Polar RP column (150 × 2 mm, 5 μm particle size, Phenomenex, Torrance, CA, USA) with a mobile phase consisting of acetonitrile containing 0.1% formic acid: distilled water containing 0.1% formic acid = 85:15 (v/v) at a flow rate of 0.2 mL/min. Column oven temperature was maintained at 30 °C.
Multiple reactions monitoring conditions for silybin and naringenin (IS) in a negative ionization mode were used at m/z 481.1 → 301.0 for silybin and m/z 271.1 → 151.3 for naringenin with a collision energy of 15 eV. Quantitation was performed using the Agilent Mass Hunter Qualitative Analysis B. 04.00 software. A standard curve for silybin (2–500 ng/mL) was prepared by serially diluting silybin stock solution. The intra-day and inter-day precision and accuracy variations were within 15%.