Naphthenic acids research

Matthew S. MacLennanChen Lab Group Meeting

March 03, 2014

Outline

• What are Naphthenic acids again?

• What Cai has tried• What I have tried• What I plan to try

Concept of Naphthenic acids

Rogers, V. V; Liber, K.; MacKinnon, M. D. Chemosphere 2002, 48, 519–527.Headley, J. V.; McMartin, D. W. J. Environ. Sci. Heal. Part A 2004, 39, 1989–2010.

Headley, J. V. et al. J. Environ. Sci. Health. A. Tox. Hazard. Subst. Environ. Eng. 2013, 48, 1145–1163.

R = alkyl groupX = COOH, R, OH, Sox, Nox, SHY = C, S, N

Note: ring structures may not befully saturated.

I have forgotten what naphthenic acids were...

• Oil sands process (affected) water (OSPW)• Acidified with H2SO4 to pH 2-2.5• Extracted into organic phase (DCM, EtOAc,

hexanes) and dried to form film• Film reconstituted in solvent of choice for

further preprocessing• = Naphthenic acids fraction compounds

(NAFCs)

What Cai has tried

• Acidify native sample• Extract into EtOAc (dry sample)• Perform NHS-EDC derivatization in DMSO• Inject reaction mixture into CE-MS with 1%

HCOOH/50% MeOH acidic buffer• (PrO)3Si(PEI) coated capillary for EOF

EDC-NHS coupling

R

O

O H

EDC-NHS

R

O

NH

N

CH3

CH3

N

CH3

CH3

NH2

DMSO

OH2

EDC-NHS coupling

http://www.piercenet.com/instructions/2160650.pdf

Sample chromatogram

What I have tried

• Sample induced transient isotachophoresis (tITP) of aqueous derivatized CNLR OSPW (vial 5)

• tITP of aqueous derivatized Syn OSPW (vial 4)

Aqueous EDC-Sulfo-NHS coupling

R

O

O H

EDC, Sulfo-NHS

R

O

NH

N

CH3

CH3

N

CH3

CH3

NH2

buffered H2O, pH ~ 7.5

OH2

Aqueous EDC-Sulfo-NHS coupling

http://www.piercenet.com/instructions/2160650.pdf

Acidified derivatized Syn OSPW

Acidified derivatized Syn OSPW

Scan 505 – Suspect peak

Scan 505; m/z 100-400

Scan 505; m/z 450-700

Scan 505; m/z 700-1000

Acidified derivatized CNLR OSPWtITP injection

Scan 506 – Suspect peak

Scan 506; m/z 150-1400

1093.7 1125.2 1125.9 1138.9 1140.9 1153.5

157.7 169.7 201.7

250.8 268.4 280.0 283.6 290.1 295.8 305.4

536.3 551.3 560.6 575.7 589.5 604.2

804.5 828.5 842.7 856.6 872.0 886.7

What I plan to try

• Activation of NAs with NHS or Sulfo-NHS (UV active); Dry-stable

• Fischer esterification with MeOH-HCl; CE-ESI-MS– Commonly used derivatization in lipidomics– Good for fragmentation