GC condition: Column: DB-1(100%-polydimethylsiloxane), Length: 30m; I.D.: 0.25 mm; Film: 1.0 µm; Injection temp.: 250 °C, Detector(FID) temp.: 275 °C, Column Temp.: 80 °C initial, programmed at 10 °C/min to 250 °C, hold for 15 min. Sample: 0.2 µl in CH2Cl2.