Synergi fusion rp 80a column

Intracellular SAM was detected by ExionLC liquid chromatography (SCIEX) coupled with a 3500 QTRAP tandem mass spectrometer (ABI). Each group contained six biologically independent replications. Intracellular SAM extraction referred to the previous study.^{56 (link)} In brief, the placenta ( $100\mathrm{mg}$ ) was quickly frozen with liquid nitrogen and ground into fine powder. We added $600\mathrm{\mu }\mathrm{L}$
$0.4\mathrm{M}$ perchloric acid. After centrifugation (4°C, $\mathrm{12,000}g$ , 20 min), the supernatant ( $30\mathrm{\mu }\mathrm{L}$ ) was taken, and $2.5\mathrm{M}$
${\mathrm{K}}_3{\text{PO}}_4$ was added to adjust the pH to 5–7. After standing at 4°C for 15 min, the supernatant was taken and injected into LC-MS/MS for analyzing SAM. Reverse-phase separation was performed using a $2\times 150\mathrm{mm}$
$4\mathrm{\mu }\mathrm{m}$ Synergi Fusion-RP 80A column (Phenomenex), using a mobile phase consisting of 0.1% formic acid in water (solvent A) and 0.1% formic acid in acetonitrile (solvent B). The gradient program was as follows: 0–7 min, 25% B–99% B; 7.1–8 min, 75%–50% B; 8–10 min, 50%–25% B. Parameters: curtain gas, 10 psi; ionspray voltage, 5500V; ion source gas 1, 55 psi; ion source gas 2, 55 psi; temperature, 600°C; flow rate: $0.3\mathrm{mL}/\text{min}$ ; sample volume: $5\mathrm{\mu }\mathrm{L}$ ; scanning mode: positive ion multireaction detection (MRM). Mother ion: 399.2 and daughter ion: 250.2; declustering potential, 68V; collision energy, 22V; Dwell time, 150 s.