Table 2: Gas chromatography and mass spectrometry operating conditions for analysis of sediment sample extracts.
| 1. Gas chromatography | Hewlett packard 5890 |
| Carrier gas | Helium. Ultra-high purity, 99.9995%; 5 psi |
| Initial temperature; Time | 55 ℃ 2 min |
| Ramp rate | 15 or 20 ℃ min-1 |
| Final temperature; Time | 300 ℃ 2 min |
| Injection volume | 1 μl |
| Injection mode | Splitless, hp autosampler model 7673A |
| Injector temperature | 270 ℃ |
| Capillary column | J & W DB5-MS 30 × 0.32 mm; Df = 0.25 μm |
| GC/MS interface temperature | 270 ℃ |
| 2. Mass spectrometry | Fisons instruments trio 1000 |
| Source temperature | 250 ℃ |
| Ionisation mode | Electron impact |
| Electron energy | 70 ev |
| Emission current | 150-200 μA |
| Mass scan range | 4-550 u |
| Scan time | 0.9 sec |
| Resolution | Unit mass accuracy |