Stabilwax ms

Quantitation of isopentanol in bacterial supernatant and urine samples was performed using Agilent gas chromatography-mass spectrometry (GC-MS) with Restek Stabilwax-MS 30 m x 0.25 mm x 0.25 µm column. Briefly, 500 µL of extraction solution was added to 100 µL of samples. Extraction solution was prepared by spiking 10 µL Isopentanol-d11 (10 mg/mL) in 5 mL ethyl acetate for a final concentration of 20 µg/mL isopentanol-d11. The samples were then mixed vigorously and centrifuged at 16,000 x g for 15 mins at room temperature. The following are the GC-MS parameters used for the analysis: 1 µL injection volume; gas (He) flow rate of 1 mL/min; 40 °C for 5 minutes, ramped to 220 °C for 3.6 minutes, and held at 220 °C for 5 minutes. Selected ion monitoring (SIM) was used for quantitative MS analysis. The following target ions were monitored for quantitation: isopentanol (55.1) and internal standard isopentanol-d11 (62.2).