Purity (GC) condition: Column:DB-1 (100% -polydimethylsiloxane), Length: 30 m; I.D.: 0.25 mm; Film: 1.0 mInjection temp.: 250 °C; Detector(FID) temp.: 275 °C Column Temp.: 120 °C initial, programmed at 10 °C/min. to 250 °C hold for 15 min.; Sample: 0.2 l in DMF