Solid Phase Extraction (SPE) and Quantification of Naphthenic Acid in Milli-Q,

Simulated Groundwater and River Waters

John Headley, Jing-Long Du, Kerry Peru, Arash Janfada

Aquatic Ecosystem Protection Research Division Water Science and Technology Directorate

Environment Canada

Outline of the Presentation

What are Naphthenic Acids?

Quantification of Naphthenic acids

Merits of Solid Phase Extraction

Analysis by –ve ESI/MS

Results and Discussion

Conclusions

Oil Sands

Oil sand

Oil Sand Extraction Process

Crude Oil

Extraction Tailings

Bitumen

Tailing Pond

Processing Unit

Naphthenic acids are carboxylic acidswhich include linear and/or saturated ring

structures.

What are Naphthenic Acids?

CnH2n+ZO2N --- the carbon number

Z --- number of hydrogen atoms that are lost as the structure becomes more compact

General Structure of Naphthenic Acids

Naphthenic acid characteristics

• Naphthenic acids are the main organic toxic constituents of Oil Sands process-water

• Corrosive

Negative

Positive

• Wood preservative• Detergent

Corrosion

Refinery units Pipelines

Toxicity

Aquatic creatures

Animals

Quantification of Naphthenic Acids

Infrared Spectroscopy (IR)Fan, T.P., Energy & Fuel, 5, 371, 1991.

Fast Atom Bombardment/Mass Spectrometry (FAB/MS)CEATAG, Naphthenic Acids Background Information Discussion Report, 1998.

Gas Chromatography/Mass Spectrometry (GC/MS) Seifert, W.K., et. al. Anal. Chem. 41, 1638, 1969

Negative-Ion Electrospray Mass SpectrometryJohn V. Headley, Kerry M. Peru, Dena W. McMartin and Marcus Winkler, AOAC, 85, 1, 2002.

Water sample description

Milli-Q

Composition Composition (mg/L)

CaSO4 (DBH, DBH Chemicals, Poole, UK) 1013MgSO4 (DBH, DBH Chemicals, Toronto, Ont.) 938NaN3(DBH, DBH Chemicals, Toronto, Ont.) 525

Simulated Ground Water

South Saskatchewan River water

Experimental

Stock NA: Obtained from Athabasca Oilsandstailing pond water (pKa: 5 -6 )

Cartridges: ENV+ (crosslinked polystyrene-based polymer)(Biotage); C18 and Oasis.

Elution: Methanol

Mass Spectrometry: Electrospray

(negative-ion

mode)

Pre-wash with 10 ml of methanol & 10 ml of Milli-Q water

Load pH 3 water sample (4 to 200 ml)

Wash with 10 ml Milli-Q water. Dry for 10 min.

Elute with 4 ml of methanol

Bring the solution to dryness by blowing with N2

Re-dissolve in acetonitrile-water (50/50) plus 0.1% ammonium

hydroxide (2 to 4 ml)1 ml was taken for ESI-MS

analysis

Henderson-Hasselbalch Equation

= 100

A−

HApH = pKa + log

pKa = pH + log HAA−

Or

At pH = 3 and pKa = 5

HAA−

NA (Syncude standard) mass spectrum

100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 500 520 540m/z0

100

%

Mar_19_07_Sarah5 42 (0.605) Sm (SG, 1x1.00); Cm (31:60-108:158) Scan ES- 3.11e6222.9

220.8208.8

206.9

194.9

192.8

118.6180.8

136.6178.7

234.9

236.9

249.0

251.0

257.0 271.0

281.0

283.0

297.0

299.0

309.0

313.0323.0

0.0

0.5

1.0

1.5

2.0

2.5

3.0

510

1520

2530

3540 0

24

68

1012

14

% A

bund

ance

Carbon No. (n)- Z family

Working Sol'n Oct 27/2005Athabasca Oilsands Naphthenic Acids

1 0 0 1 2 0 1 4 0 1 6 0 1 8 0 2 0 0 2 2 0 2 4 0 2 6 0 2 8 0 3 0 0 3 2 0 3 4 0 3 6 0 3 8 0 4 0 0 4 2 0 4 4 0 4 6 0 4 8 0 5 0 0 5 2 0 5 4 0m / z0

1 0 0

%

F e b _ 2 6 _ 0 7 _ D U 1 7 3 8 ( 0 . 5 4 8 ) S m ( S G , 1 x 1 . 0 0 ) ; C m ( 2 7 : 6 6 ) S c a n E S - 3 . 8 0 e 51 5 2 . 7

1 4 6 . 5

1 1 8 . 7

1 1 1 . 71 3 6 . 6

3 3 0 . 8

2 5 0 . 8

1 8 0 . 6

1 7 0 . 7

2 3 2 . 7

2 2 2 . 92 1 1 . 7

1 9 4 . 8

2 3 4 . 8

2 3 6 . 9

2 8 8 . 8

2 5 4 . 8

2 8 2 . 9

2 7 0 . 8

3 1 6 . 73 1 0 . 7

2 9 4 . 9

3 6 8 . 8

3 5 2 . 93 3 2 . 8

3 3 4 . 9

5 0 4 . 7

4 5 2 . 7

4 2 4 . 84 0 9 . 83 8 4 . 8

3 9 0 . 9

4 0 0 . 94 1 0 . 9

4 3 6 . 9

4 6 6 . 7 4 8 8 . 7

4 6 8 . 94 9 6 . 8

5 4 4 . 65 2 6 . 75 0 6 . 8

5 3 4 . 6

5 4 6 . 4

5 4 9 . 0

1 0 0 1 2 0 1 4 0 1 6 0 1 8 0 2 0 0 2 2 0 2 4 0 2 6 0 2 8 0 3 0 0 3 2 0 3 4 0 3 6 0 3 8 0 4 0 0 4 2 0 4 4 0 4 6 0 4 8 0 5 0 0 5 2 0 5 4 0m / z0

1 0 0

%

F e b _ 2 8 _ 0 7 _ D U 5 1 4 1 ( 0 . 5 9 0 ) S m ( S G , 1 x 1 . 0 0 ) ; C m ( 2 7 : 6 4 - 7 2 : 1 3 4 ) S c a n E S - 5 . 5 4 e 52 2 2 . 9

2 0 8 . 9

2 0 6 . 9

1 9 4 . 8

1 9 2 . 9

1 8 0 . 9

1 1 8 . 7 1 3 6 . 8 1 7 8 . 8

1 6 4 . 91 5 2 . 8

2 3 4 . 92 3 6 . 9

2 5 3 . 0

2 5 1 . 0 2 6 7 . 0

2 8 0 . 9

2 8 3 . 1

2 9 5 . 02 9 7 . 1

2 9 9 . 1

3 1 0 . 9

3 1 3 . 03 2 5 . 0

3 3 6 . 93 3 8 . 9

3 4 1 . 23 5 3 . 0

Simulated groundwater, 69 mg/L

Before extraction

After extraction

1 0 0 1 2 0 1 4 0 1 6 0 1 8 0 2 0 0 2 2 0 2 4 0 2 6 0 2 8 0 3 0 0 3 2 0 3 4 0 3 6 0 3 8 0 4 0 0 4 2 0 4 4 0 4 6 0 4 8 0 5 0 0 5 2 0 5 4 0m / z0

1 0 0

%

F e b _ 2 6 _ 0 7 _ D U 1 5 4 0 ( 0 . 5 7 6 ) C m ( 2 6 : 5 7 ) S c a n E S - 5 . 3 4 e 53 3 0 . 6

1 5 2 . 7

1 5 2 . 3

1 3 6 . 61 1 1 . 6 1 1 8 . 3

2 5 0 . 82 3 2 . 6

1 8 0 . 6

1 7 0 . 6

1 8 0 . 8

2 1 1 . 8

1 9 4 . 7

2 1 6 . 6

2 1 8 . 7

2 5 0 . 7

2 3 4 . 6

2 4 4 . 0

2 8 8 . 6

2 5 1 . 5

2 5 4 . 9

2 8 2 . 8

2 7 2 . 6

3 1 6 . 6

3 1 1 . 1

3 0 0 . 9

3 6 8 . 7

3 5 2 . 73 3 2 . 7

3 3 3 . 0

3 3 4 . 6

4 8 8 . 6

4 6 6 . 7

4 3 6 . 74 0 9 . 7

3 8 4 . 63 7 0 . 6 3 9 0 . 7

3 9 6 . 8

4 2 8 . 8

4 2 4 . 8

4 1 0 . 6

4 5 3 . 04 5 0 . 5

4 7 2 . 8

4 8 5 . 9

5 0 4 . 7

4 9 0 . 7 5 4 6 . 25 2 6 . 8

5 2 2 . 75 1 6 . 3 5 3 8 . 2

1 0 0 1 2 0 1 4 0 1 6 0 1 8 0 2 0 0 2 2 0 2 4 0 2 6 0 2 8 0 3 0 0 3 2 0 3 4 0 3 6 0 3 8 0 4 0 0 4 2 0 4 4 0 4 6 0 4 8 0 5 0 0 5 2 0 5 4 0m / z0

1 0 0

%

F e b _ 2 8 _ 0 7 _ D U 4 4 4 2 ( 0 . 6 0 5 ) S m ( S G , 1 x 1 . 0 0 ) ; C m ( 3 4 : 4 8 - 5 3 : 9 9 ) S c a n E S - 3 . 8 5 e 52 1 6 . 6

1 9 4 . 8

1 1 8 . 7

1 1 1 . 7

1 3 6 . 8

1 2 0 . 8

1 9 2 . 8

1 5 6 . 9

1 4 2 . 91 7 0 . 8

2 0 8 . 9

2 2 2 . 9

2 8 3 . 12 5 5 . 0

2 3 4 . 8

2 3 6 . 9

2 6 7 . 02 8 1 . 1

2 9 7 . 1

3 1 1 . 1

3 2 5 . 0

3 3 6 . 84 5 6 . 7

3 3 8 . 83 5 9 . 0

3 5 3 . 13 6 1 . 0

4 1 2 . 93 8 0 . 8 3 9 3 . 1 4 3 5 . 0

4 7 8 . 9

4 5 8 . 9 4 8 0 . 85 3 2 . 95 0 0 . 8

After extraction

Before extraction

Simulated groundwater, 0.069 mg/L

100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 500 520 540m/z0

100

%

0

100

%

Feb_28_07_DU35 40 (0.576) Sm (SG, 1x1.00); Cm (27:58-77:124) Scan ES- 1.58e5146.7

118.8

102.8

104.8

136.7

174.8

152.6

158.7

180.8304.8294.8

288.7

254.6238.8232.8

216.6198.8

182.8208.6

266.9282.8

310.7

368.9352.7322.8

336.8384.9 434.9424.8396.8 440.8 498.7458.9 475.1 508.8

533.1 540.9

Feb_28_07_DU30 41 (0.591) Sm (SG, 1x1.00); Cm (27:59-78:132) Scan ES- 1.75e5222.8

220.9209.0

206.8

194.9

188.7

180.9148.9136.6118.7

164.6

237.0

265.1252.9 282.9267.0

281.0

293.0310.9

313.0

335.1 339.0 353.2367.0 381.1 395.3

Before extraction

After extraction

River water, 6.9 mg/L

100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 500 520 540m/z0

100

%

Feb_28_07_DU23 41 (0.590) Sm (SG, 1x1.00); Cm (24:71-90:137) Scan ES- 2.29e5297.0

283.1

281.0

265.0

254.9

242.9238.8

222.7220.8

219.0

204.8

192.8191.0

176.7

136.9

124.8

164.9150.9

267.0

311.0 325.0338.9

353.0

367.1369.1

381.1

395.1397.0

411.1

423.0425.1

437.2453.1

465.0467.1

River water, 0.069 mg/L

After extraction

Sample mg/L Recovery Mean recovery RSD

200 mL blank 0.04 mL blank 0.0

S 0.069-1 0.060 86.7S 0.069-2 0.057 82.8 85.3 2S 0.069-3 0.060 86.3

S 6.9-1 3.7 53.2S 6.9-2 4.4 63.1 55.9 18S 6.9-3 3.5 67.7

S 69-1 44.2 64.1S 69-2 46.4 67.2 66.3 3S 69-3 46.7 67.7

S = Simulated ground water

Simulated Groundwater

Sample mg/L Corr. Conc. Recovery Mean recovery RSD

200 mL blank 69.34 mL blank 2.0

R 0.069-1 69.8 0.005 7.6R 0.069-2 71.4 0.021 30.4 30.5 75R 0.069-3 73.0 0.037 53.6

R 6.9-1 7.6 5.6 81.2R 6.9-2 7.3 5.3 76.8 83.1 9R 6.9-3 8.3 6.3 91.3

R 69-1 46.8 44.8 64.9R 69-2 46.4 44.4 64.3 61.2 10R 69-3 39.6 37.6 54.4

R = South Saskatchewan River water

River Water

Sample mg/L Recovery Mean recovery RSD

M 0.069-1 0.050 72.2M 0.069-2 0.041 60.0 65.5 5M 0.069-3 0.045 64.9

M 6.9-1 4.2 60.9M 6.9-2 4.0 57.4 61.4 7M 6.9-3 4.6 66.0

M 69-1 43.8 63.5M 69-2 46.1 66.8 63.5 5M 69-3 41.6 60.3

M =Milli-Q water

Milli-Q Water

200 mL blank 0.04 mL blank 0.0

Conclusions:

ENV+ cartridge efficiently extracts the non-dissociated naphthenic acid and desalts the final extract.

There is a significant matrix effect in the river water samples due to natural carboxylic acids (humic, fulvicetc.) in the natural river water systems.

The described SPE procedure significantly reduced the ion suppression during ESI caused by matrix interference.

ENV+ is more efficient than Oasis and C18 cartridges in extraction of NAs.

Thank you!