ENVIRONMENTALENVIRONMENTALANALYSISANALYSISI. Solid Phase ExtractionI. Solid Phase Extraction

ENVIRONMENTALENVIRONMENTALANALYSISANALYSISI. Solid Phase ExtractionI. Solid Phase Extraction

oil & grease –

EPA method 1664

O & G : SummaryO & G : SummaryO & G : SummaryO & G : Summary

Definitions

Liquid / Liquid Extraction methods

Solid Phase Extraction methods

Optimizing SPE: Special O&G Tube

DefinitionsDefinitionsDefinitionsDefinitions

The Samples

Surface and Saline WatersIndustrial and Domestic Aqueous Wastes

Waste Water Sludge

Definitions (cont.)Definitions (cont.)Definitions (cont.)Definitions (cont.)

The Analytes

HEM: n-Hexane Extractable MaterialTPH (or SGT-HEM): Total Petroleum Hydrocarbons = Silica Gel Treated HEM

(HEMs not adsorbed by silica gel)

Examples: non-volatile hydrocarbons, waxes, soaps, vegetable oils, animal fats, greases.

Solvent: CCl4

Hungarian Standard MSZ 260/22-74Solvent: Freon-113

ASTM Method 413.1

Montreal Protocol on Substances that Deplete the Ozone Layer phase out the use of CFCs

Solvent: n-HexaneEPA Method 1664

L / L ExtractionL / L ExtractionL / L ExtractionL / L Extraction

L / L Extraction of O & GL / L Extraction of O & GL / L Extraction of O & GL / L Extraction of O & G

EvaporationEvaporation PurgePurge

WeighWeigh Re-dissolveRe-dissolve Silica Gel Silica Gel TreatmentTreatment

EvaporationEvaporation PurgePurge WeighWeigh

NaNa22SOSO44

DryingDrying

pH ~2

The solvent (n-Hexane) is lighter than waterrepouring the water means more

labour

Solvent-related matrix interferencessee Table (next slide)

Four QA/QC samples per analytical batch- blank - blank spike- matrix spike - ms

duplicate

Features of Method 1664Features of Method 1664Features of Method 1664Features of Method 1664

EPA CFC Replacement StudyEPA CFC Replacement StudyEPA CFC Replacement StudyEPA CFC Replacement Study

(mg/L) CFC L/L n-C6 L/L SPED

POTW 27 25 25

Pump manufacturing 350 330 350

Chemical manufacturing 9 < 5 22

Meat processor 22 27 54

Packaging plant 14 23 25

EPA 1664 CriteriaEPA 1664 CriteriaEPA 1664 CriteriaEPA 1664 Criteria

Acceptance Criteria

MS / MSD Recovery RSD

HEM 79-114 18

SGT-HEM 66-114 24

EPA 1664: Performance-Based Method

Why SPE?Why SPE?Why SPE?Why SPE?

Reduce solvent usageReduce solvent usage

Eliminate emulsion problemEliminate emulsion problem

Reduce handlingReduce handling

Readily amenable to automation

O & G on ISOLUTE TPHO & G on ISOLUTE TPHO & G on ISOLUTE TPHO & G on ISOLUTE TPH

Sample: #2 Fuel Oil

1. Sample pre-treatment

2. Column solvation

3. Column pre-equilibrium

4. Sample application

5. Interference elution

6. Analyte elution

HCl to pH=2, HCl to pH=2, MeOHMeOH wetting agentwetting agent

10 mL MeOH10 mL MeOH

10 mL water10 mL water

One liter in One liter in 1/2 1/2 hourhour

10 mL water, 10 mL water, 1515 min N min N22

2 x2 x 33 mL mL THF/nC6 1:1 THF/nC6 1:1

Petroleum Hydrocarbon Petroleum Hydrocarbon Recoveries: ISOLUTE TPHRecoveries: ISOLUTE TPHPetroleum Hydrocarbon Petroleum Hydrocarbon Recoveries: ISOLUTE TPHRecoveries: ISOLUTE TPH

Conc % rec Stdmg/L vs std Avg Dev

9094

20.0 104938993

94 5

8892

120.0 93899088

90 2

EPA Represention of O & G EPA Represention of O & G FractionsFractionsEPA Represention of O & G EPA Represention of O & G FractionsFractions

Formerly: Formerly: #2 Fuel Oil or Wesson Oil#2 Fuel Oil or Wesson Oil

Currently: Currently: HexadecaneHexadecane - non-polar... - non-polar...

Stearic Stearic AcidAcid - polar fraction - polar fraction

CH3 (CH2)14 CH3

CH3 (CH2)16 C

O

OH

Selective ElutionSelective ElutionSelective ElutionSelective Elution

Polar vs. Non-Polar Fractions First: Non-polar solvent Non-polar

interactions

Second: Mixed solvent Polar and Non-polar interactions

Selective Elution (cont.)Selective Elution (cont.)Selective Elution (cont.)Selective Elution (cont.)

Stearic AcidStearic AcidHexadecaneHexadecane

HexaneHexane Hexane / THFHexane / THFHexadecaneHexadecane + Stearic + Stearic

AcidAcid

Recoveries from Selective Recoveries from Selective Elution Elution Recoveries from Selective Recoveries from Selective Elution Elution

20 ppm spike20 ppm spike(90% C16, 10% stearic (90% C16, 10% stearic

acid) acid)

Hexadecane (TPH) 96%Hexadecane (TPH) 96%Stearic Acid 113%Stearic Acid 113%

Extraction of EPA 1664 Extraction of EPA 1664 Standards at High Standards at High Concentrations Concentrations

Extraction of EPA 1664 Extraction of EPA 1664 Standards at High Standards at High Concentrations Concentrations

Stearic acid spike precipitates Stearic acid spike precipitates from solutionfrom solution

Plugging of sample lines and Plugging of sample lines and extraction cartridgesextraction cartridges

Low recoveries Low recoveries

Building a TPH / Total O & G Building a TPH / Total O & G ColumnColumnBuilding a TPH / Total O & G Building a TPH / Total O & G ColumnColumn

FritsFrits

PolyesterPolyesterDepth FilterDepth Filter

Large ParticleLarge ParticleSpecial PhaseSpecial Phase

Std. ParticleStd. ParticleSpecial PhaseSpecial Phase

SilicaSilica

Polyester Depth FilterPolyester Depth FilterPolyester Depth FilterPolyester Depth Filter

Oil and Grease:Oil and Grease: Distributes grease to Distributes grease to prevent frit and cartridge pluggingprevent frit and cartridge plugging

Particulates:Particulates: Distributes solids to Distributes solids to prevent packing from pluggingprevent packing from plugging

Loading Rate with Depth FilterLoading Rate with Depth FilterLoading Rate with Depth FilterLoading Rate with Depth Filter

Avg Loading Time, min: Avg Loading Time, min: 3434

Loading Rate, mL/min : Loading Rate, mL/min : 3030

(n = 7)(n = 7)

O & G on ISOLUTE O & GO & G on ISOLUTE O & GO & G on ISOLUTE O & GO & G on ISOLUTE O & G

1. Sample pre-treatment

2. Column solvation

3. Column pre-equilibrium

4. Sample application

5. Interference elution

6. Analyte elution

HCl to pH=2, HCl to pH=2, MeOHMeOH wetting agentwetting agent(sample temperature?)(sample temperature?)

10 mL MeOH10 mL MeOH

10 mL water, pH 210 mL water, pH 2

1/2 liter in 1/2 liter in 15-30 15-30 minmin

10 mL water, 10 mL water, 3030 min N min N22

1st: 1st: 33 mL mL HexaneHexane2nd: 2nd: 33 mL mL THF/nC6 1:1THF/nC6 1:1

Impact of Various FactorsImpact of Various FactorsImpact of Various FactorsImpact of Various Factors

Elution solvent:Elution solvent: Hexane / THF Hexane / THF

Wetting Agent:Wetting Agent: 1% Methanol 1% Methanol

Sorbents: Sorbents: 1/2 g or 1 g ISOLUTE O&G 1/2 g or 1 g ISOLUTE O&G

Bottle wash:Bottle wash: 20 mL Acetone + 80 mL water 20 mL Acetone + 80 mL water

Recoveries for TPH / Total O&GRecoveries for TPH / Total O&GRecoveries for TPH / Total O&GRecoveries for TPH / Total O&G

Spike, mg/L Recovery, %%RecoveryTotal O & G

120 Hexadecane: 92Stearic Acid: 104

98

60 Hexadecane: 94Stearic Acid: 96

95

24 Hexadecane: 88Stearic Acid: 102

95

12 Hexadecane: 87Stearic Acid: 100

94