Heptacosane C27 1.23 1.61 1.37 1.52 2.14 2.13 1.33 1.26 1.52 1.64 0.28 0.10 0.31 0.46 Octacosane C28 0.85 1.19 1.05 1.25 1.51 1.28 1.03 1.02 1.30 1.19 0.19 0.04 0.20 0.30 Nonocosane C29 0.78 0.94 0.72 1.03 1.09 1.10 0.74 0.78 0.85 0.82 0.12 0.00 0.08 0.23 Triacontane C30 0.19 0.46 0.43 0.34 0.81 0.60 0.58 0.63 0.53 0.57 0.05 0.00 0.06 0.16 Untriacontane C31 0.34 0.36 0.33 0.27 0.60 0.48 0.34 0.31 0.28 0.35 0.00 0.00 0.01 0.07 Dotriacontane C32 0.17 0.18 0.24 0.27 0.42 0.35 0.17 0.23 0.19 0.14 0.00 0.00 0.00 0.04 Tritriacontane C33 0.16 0.07 0.38 0.10 0.35 0.22 0.11 0.22 0.15 0.17 0.00 0.00 0.00 0.03 Tetratriaconta ne C34 0.05 0.14 0.25 0.12 0.49 0.07 0.10 0.20 0.15 0.12 0.00 0.00 0.00 0.01 Pentatriaconta ne C35 0.06 0.06 0.04 0.00 0.18 0.03 0.07 0.10 0.00 0.04 0.00 0.00 0.00 0.00 *Relative percent calculated from the relative peak area of the target n-alkane to the total peak areas of the resolved n-alkanes for each sample.
By contrast, crude oil is distinguishable by the presence of a relatively large unresolved complex mixture (UCM) due to poor resolution of the peaks during separation in a gas chromatographic column. This leads to the formation a large “hump” or UCM in the GC trace which is used as a marker to differentiate crude oil form Bunker "c" oil. Table 8 presents a comparison of some of the distinguishing features between refined and crude oils obtained from previous analyses conducted by IMA. [See plate 19, Appendix C as one example of a crude oil chromatogram trace from a sample in Trinidad]. A comparison of the common fuel oils show that Bunker “a” oil or Fuel oil #2 (also referred to as diesel) is recognizable by its light brown or yellow colour, Bunker “b” oil typically contains of a mixture of fuel oil #3 and fuel #4 respectively and Bunker "c" oil or fuel oil #6 is characteristically dark in colour and very viscous. Table 8: Summary of some of the distinguishing features between refined and crude oils for comparison. Parameters Fuel oil #1 Fuel oil #2 (Bunker a) Fuel oil #3 Fuel oil #6 (Bunker c) Crude oils n-alkane range C10 – C19 C10 – C24 C10 – C24 C10 – C27 C10 – C70 άMaxima of n- alkane range C13 C14 – C16 C17- C18 C19 -C21 Varies for different crudes *UCM and +Hydrocarbon GC profile mode Relatively small UCM. Unimodal GC profile Relatively small UCM. Unimod GC profile Relatively small UCM. Unimodal GC profile Relatively medium UCM. Usually mixed with Fuel oil #2 to give Bimodal GC profile Relatively large UCM. Mixed oil have Bimodal GC profile
27.674 28.904 30.249 31.691 Time--> 3 33 3 3 3 33 3 . 3 3..4 .414 .4 .44.4 5.00 10.00 15.00 20.00 25.00 30.00 35.00
Plate 7: Aliphatic chromatogram of Sample 7, Sample of source oil A at spill site of Petrotrin Point a-Pierre, Thick black oil in bottle., thick black oil in bottle Note chromatogram indicated with maxima centered around nonadecane (n-C19), retention time of 17.94 mins. Abundance TIC: SAMP7.D\data.ms 1200000 17.947 1100000 1000000 8.963 7.0 85.2700 14.319 19.612 21.191 900000 14.428 12.356 11.126 22.667 800000 10.325 11.452 8.437 16.350 24.041 700000 600000 9.1303.559143.323 12.459 11.784 13.1458.4080 25.317 500000 6. 987.0271 12.1238.8884 20.241 26.518 400000 300000 6. 578.695310.954 6.394 5.513 6.199 27.674 28.910 200000 5 .50.39294 5.444 3. 1 4 4 442..2..155833971472 3 3 3 3 333.4 44.4...78.8.04142057292223110 30.249 31.691 33.23452.645 Time--> 5.00 10.00 15.00 20.00 25.00 30.00 35.00 Plate 8: Aliphatic chromatogram of Sample 8, Sample of source oil B (a duplicate of sample 7) at spill site of Petrotrin Point a-Pierre, thick black oil in bottle. Note chromatogram indicated with maxima centered around nonadecane (n-C19), retention time of 17.94 mins. Abundance TIC: SAMP8.D\data.ms 900000 17.941 800000 19.606 700000 8.963 8.700 14.31169.179 14.428 21.185 600000 7.058 12.356 11.126 16.350 22.662
Plate 11: Aliphatic chromatogram of Sample 11, collected from vessel named “Transporter II” at the LABIDCO Industrial estate from compartment labeled “A”. Note chromatogram indicated with maxima centered around heptadecane (n-C17), retention time of 14.34 mins. Contains light fraction of hydrocarbons. Large peak of tri-methyl benzene at retention time 3.13 mins. Abundance TIC: 11a.D\data.ms 6000000 5500000 5000000 3.133 14.336 12.374 4500000 10.342 16.196 17.953 4000000 8.448 19.618 3500000 6.978 14.445 3000000 5.570 21.191 4.243 250000 30.447 6.594 9.564 16.362 13.329 22.667 24.035 2000000 8.076 8.969 4.609 8.70161.441 1500000 7 7.3.61953 13.495 11.71733.604 13.1755.8298 25.311 26.507 1000000 500000 22.261 27.668 28.904 30.238 343.253.36772.2161 Time--> 5.00 10.00 15.00 20.00 25.00 30.00 35.00 Plate 12: Aliphatic chromatogram of Sample 12, collected from vessel named “Transporter II” at the LABIDCO Industrial estate from compartment labeled “B”. Note chromatogram indicated with two maxima centered around tridecane (n-C13) and hexadecane (n-C16) with retention times of 6.99 and 12.37 mins respectively. Contains light fraction of hydrocarbons. Large peak of tri-methyl benzene at retention time 3.13 mins. Abundance 3.127 TIC: 12a.D\data.ms 6500000 6.989 5.576 600000 30 .44.42243 8.454 5500000 5000000 12.374 10.348 14.336 4500000 4000000 4.6 069.600
7.390 16.196 17.958 19.618 4.546 14.445 21.197 3500000 3000000 2500000 5.519 8.082 5.942 9.570 7 7..3 6816.59469 8.711 9.369 16.362 13.335 22.673 24.035 2000000 1500000 1000000 11.447 11.11338.495 11.717313.46.05471 25.311 26.513 500000 Time--> 5.00 10.00 15.00 20.00 25.00 30.00 35.00 0
16.373 22.679 4000000 6.594 3500000 7 8.3.09 980.2581 13.346 4.609 7 . 878.0.7941715 24.046 3000000 2500000 2000000 1500000 1000000 500000 5.524 11.452 13.506 11.784 25.317 26.518 27.674 28.904 30.243 31.685 35.633 Time--> 5.00 10.00 15.00 20.00 25.00 30.00 35.00
Plate 17: Aliphatic chromatogram of fuel oil #2 (diesel oil). Note end of peaks in chromatogram at C28 at time 31.72 mins. Abundance TIC: D(diesel(Ali).d\data.ms C14 C16 13.998 C18 10.040 11.921 15.989 19.621 4000000 17.859 16.101 21.279 3500000 3000000 2500000 2000000 C13 8.480 14.969 18.028 22.846 24.320 25.680 1500000 1000000 C10 6.834 5.143 26.948 28.141 500000 3.606 29.274 C28 30.452 31.719 Time--> 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 Plate 18: Aliphatic chromatogram of fuel oil #1. Abundance C12 6.434 7.806 TIC: FU1ALI.D\data.ms 1200000 1100000 1000000 5.049 C14 9.298 7.256 6.510 C15 5.880 11.427 C10 3.746 7.73.78771 C16 0 0 0 0 0