Approaches to quantify the biogenic interference on Petroleum hydrocarbon levels

Transcription

1 Approaches to quantify the biogenic interference on Petroleum hydrocarbon levels Chris Swyngedouw Remtech 2007

2 Outline GC/FID hydrocarbon analysis Silica gel treatment Approaches to quantify the biogenic interference slide number 2

3 slide number 3 Gas Chromatography

4 Hydrocarbon Analysis Developed to provide quantitative information. Example - for regulatory decisions CCME method provides some characterization hydrocarbon ranges. Information about composition of the hydrocarbon is not provided. Methods are not capable of distinguishing between materials with similar properties. slide number 4

5 Organic compounds detected by GC/FID Volatile aromatics (BTEX) Polyaromatic hydrocarbons (PAHs) Alkylated PAHs Hetero PAHs (S and N) Waxes and Asphalthenes Organic acids (fatty acids) slide number 5

6 slide number 6 Farm soil

7 slide number 7 Plant material

8 Biogenic Hydrocarbons Odd carbon-numbered n-alkanes are much abundant than even carbon- numbered n- alkanes in the C21- C33 range. Note absence of UCM; Presence of "biogenic cluster" in the GC. slide number 8

9 slide number 9 Peat- extracted

10 CCME Summary of Tier I Levels (mg/kg) for surface soil. Land Use Soil Texture Fraction 1 C6-C10 Fraction 2 C10-C16 Fraction 3 C16-C34 Fraction 4 C old 2007 old 2007 old Old/new Agricultural Coarse-grained (90) Fine-grained 210(170) 260(180) (250) Residential/ Coarse-grained (90) Parkland Fine-grained 210(170) 260(180) (250) Commercial Coarse-grained 320(240) 310(300) (90) Fine-grained 320(170) 660(180) 260(230) 1500(250) Industrial Coarse-grained 320(240) 310(300) (90) Fine-grained 320(170) 660(180) 260(230) 1500( Values in brackets for fractions 1 and 2 considers additional potable groundwater protection For complete levels, consult Tables in the Technical Supplement Document slide number 10

11 Interference with CCME fractions F2 F3 F4 slide number 11

12 Soxhlet (CCME) gm (CCME 5 gm) Mix with drying agent hr. Soxhlet with Hexane / Acetone Cleanup Concentrate Assess slide number 12

13 slide number 13 Soxhlets

14 slide number 14 Rotatory evaporator

15 slide number 15 Concentrated Soxhlet extracts

16 slide number 16 Silica gel cleanup

17 slide number 17 GC vials

18 slide number 18 High temp GC/FIDs

19 C10-C60 C60 Assessment 2.5e4 CARBON NUMBER F3 F4 F2 F4HTGC Sig. 1 in C:\HPCHEM\...\035F0101.D Time (min.) slide number 19

20 Pure Canola Oil 3.0e5 CARBON NUMBER Sig. 1 in C:\HPCHEM\...\014F0201.D slide number Time (min.)

21 2.2e5 Canola and crude oil CARBON NUMBER Sig. 1 in C:\HPCHEM\...\018F0101.D slide number Time (min.)

22 Canola oil Removal 2.2e5 CARBON NUMBER Sig. 1 in C:\HPCHEM\...\018F0101.D 2.2e5 CARBON NUMBER Sig. 1 in C:\HPCHEM\...\017F0101.D Time (min.) Time (min.) 2.2e5 CARBON NUMBER Sig. 1 in C:\HPCHEM\...\016F0101.D 2.2e5 CARBON NUMBER Sig. 1 in C:\HPCHEM\...\015F0101.D Time (min.) Time (min.) slide number 22

23 Silica gel treatment Losses with each treatment fraction % Change Before/after batch F2 16 % F3 13 % C34-C50 1 % C50+ 30% slide number 23

24 Natural Interferences - Peat F2 F3 F4 slide number 24

25 slide number 25 Biodiesel waste water

26 Biogenic material Biogenic interference and silica gel Cleanup Tundra peat False positives slide number 26

27 Conceptual Model TEH = TPH + TOM TPH = TEH - TOM TEH from CCME fractions F2 - F4 TOM from? TPH is then the true petroleum hydrocarbons slide number 27

28 TOM Approaches Blanks Chromatographic separation GC/MS Standard additions TOC + silica gel slide number 28

29 Blank Subtraction Run 1: blank/amendments Run 2: sample Result: TPH = sample - blank slide number 29

30 slide number 30 Peat + diesel

31 slide number 31 Coal in this sample

32 slide number 32 Coal

33 slide number 33 extracted wood

34 Example - coal TOC = TC TIC (carbonates) TOC =? TOM (LOI) slide number 34

35 slide number 35 GC/MS?

36 Use of GC/MS % plant material PHC Gasoline + plant material Ratios Still a chromatographic guess. slide number 36

37 GC/MS Soil + plant material + asphalt MOG 2800 mg/kg TOC 3.55% On GC/MS no PHC detected On high temp GC mostly C40+ MS would not detect this slide number 37

38 slide number 38 Plant material + asphalt

39 Asphalt + peat 2.5e4 CARBON NUMBER Sig. 1 in C:\HPCHEM\...\057F0201.D Time (min.) slide number 39

40 Peat Peat + PHC no SG done Subtract blank peat No blank, do extr.hc before and after SG 2 silica gel treatments slide number 40

41 slide number 41 Fresh crude and peat

42 standard additions area TEH result slide number 42

43 Standard addition experiments Eg % wood by volume Works in theory, problem with real samples (normalization) TOC before and after extraction Bulk density, moisture Need relationship between BD and TOC slide number 43

44 Combination approach Extract sample as per PHC method Analyzed for TOC and PHC before and after SG cleanup Results used for CTGM interpretation only Presence of biogenic interference Biogenic chromatographic fingerprint Effectiveness of SG cleanup slide number 44

45 Some further considerations Difference between TOC and LOI The need for marker compounds Ratio marker compound/total amendments Surrogates for F2 F4 Reverse surrogate for SG treatment. slide number 45