ENVIRONMENTALENVIRONMENTALANALYSISANALYSISI. Solid Phase ExtractionI. Solid Phase Extraction

ENVIRONMENTALENVIRONMENTALANALYSISANALYSISI. Solid Phase ExtractionI. Solid Phase Extraction

SPE sorbents

SORBENT SORBENT SELECTIONSELECTIONSORBENT SORBENT SELECTIONSELECTION

Which Sorbent?Which Sorbent?Which Sorbent?Which Sorbent?

EPA 525.1 analytes

OC / OP / ON-pesticides

PCBs

PAHs

Phthalates

Analyte PropertiesAnalyte PropertiesAnalyte PropertiesAnalyte Properties

OCH2COOH

Cl

Cl

2,4 D

Benzo [b] fluoranthene

Heptachlor

2CCl

ClCl

Cl

Cl

Cl

InstrumentationInstrumentationInstrumentationInstrumentation

Tekmar AutoTrace SPE workstation

HP 5890 GC w. 5971 MSD

IST Isolute SPE columns

The Method: EPA 525.1The Method: EPA 525.1The Method: EPA 525.1The Method: EPA 525.1

1. Sample pre-treatment

2. Column solvation

3. Column equilibration

4. Sample application

5. Interference elution

6. Analyte elution

NaNa22SOSO3, 3, HCl to pH=2, HCl to pH=2,

IPAIPA wetting agent wetting agent

1010 mL mL IPAIPA

1010 mL water mL water

One liter in One liter in 1/21/2 hour hour

10 mL water, 10 mL water, oneone min N min N22

Two x Two x 22 mL mL Ace/EtAc 75:25 Ace/EtAc 75:25

6060 minutes for ten samples minutes for ten samples

A Data A Data SnapshotSnapshotA Data A Data SnapshotSnapshot

|<------------- C8 (EC) 0.5% IPA AT 4 DEG ------------>|

COMPOUND REP 1 REP 2 REP 3 AVG RSD1 hexachlorocyclopentadiene 81 70 84 78 72 dimethylphthalate 95 85 98 93 73 acenaphthalene 97 89 96 94 54 acenaphthene-d10 IS IS IS IS IS5 2-chlorobiphenyl 90 83 92 89 56 diethylphthalate 107 99 106 104 47 fluorene 93 85 92 90 48 2,3-dichlorobiphenyl 81 74 81 79 49 hexachlorobenzene 75 68 73 72 3

10simazine 86 80 88 84 411atrazine 102 93 102 99 512pentachlorophenol ND ND ND ND ND13lindane 100 90 108 99 914phenanthrene-d10 IS IS IS IS IS15phenanthrene 87 80 86 84 416anthracene 84 76 81 81 4172,4,5-trichlorobiphenyl 80 73 76 76 418alachlor 120 115 115 117 319heptachlor 95 88 90 91 420di-n-butylphthalate 118 109 112 113 5212,2',4,4'-tetrachlorobiphenyl 89 79 80 83 622aldrin 88 81 85 85 323heptachlor epoxide 103 95 96 98 5242,2',3',4,6-pentachlorobiphenyl 95 83 85 88 625gamma-chlordane 106 94 94 98 726pyrene 94 82 84 86 627alpha-chlordane 104 92 93 97 728trans nonachlor 105 93 93 97 7292,2',4,4',5,6'-hexachlorobiphenyl 91 75 86 84 830endrin 105 100 98 101 431butylbenzylphthalate 121 122 113 119 532di(2-ethylhexyl)adipate 134 128 122 128 633benz[a]anthracene 93 79 85 86 734chrysene d-12 IS IS IS IS IS35chrysene 92 80 84 85 6362,2'3,3',4,4',6-heptachlorobiphenyl 100 84 95 93 937methoxychlor 126 113 107 115 10382,2',3,3',4,5',6,6'-octachlorobenzene 97 79 89 88 939di(2-ethylhexyl)phthalate 136 130 123 129 640benzo[b]fluoranthene 95 88 86 90 541benzo[k]fluoranthene 97 86 88 90 642benzo[a]pyrene 91 85 83 86 443perylene-d12 100 111 101 104 644indeno[1,2,3,c,d]pyrene 110 109 95 105 845dibenz[a,h]anthracene 120 117 103 113 946benzo[g,h,i]perylene 101 97 92 96 4

Reducing the DataReducing the DataReducing the DataReducing the Data

39di(2-ethylhexyl)phthalate 136 130 123 129 640benzo[b]fluoranthene 95 88 86 90 541benzo[k]fluoranthene 97 86 88 90 642benzo[a]pyrene 91 85 83 86 443perylene-d12 100 111 101 104 644indeno[1,2,3,c,d]pyrene 110 109 95 105 845dibenz[a,h]anthracene 120 117 103 113 946benzo[g,h,i]perylene 101 97 92 96 4

OVERALL: 88

EARLY: 91MID: 85

LATE: 89

Bonded Silica SurfaceBonded Silica SurfaceBonded Silica SurfaceBonded Silica Surface

S iO

S iO

S iO S i

O

S iO

S i

S i OS i

OS iO H

S iO H

O HO H

C18C18C8C8C2C2PhenylPhenyl

C18C18C8C8C2C2PhenylPhenyl

Sorbent ScreeningSorbent ScreeningSorbent ScreeningSorbent Screening

C2C8 C18 PH

Which Sorbent?Which Sorbent?

ELUTION VOLUME: 2 + 2 mLELUTION VOLUME: 2 + 2 mLCONDITIONING: IPACONDITIONING: IPASOLVENT: Acetone / EtAc 75:25SOLVENT: Acetone / EtAc 75:25

ABSOLUTE RECOVERIES ABSOLUTE RECOVERIES ± 4%

C18 (EC) C18 (EC) C2 PhenylC18 (EC) C18 (EC) C2 Phenyl 1g 1/2 g 1 g 1 g1g 1/2 g 1 g 1 g

SORBENT TYPESORBENT TYPE

8989 75 75 14 14 39 39 7575 75 75 70 70 60 60 6868 67 67 85 82 85 82 7676 73 73 56 66 56 66

Small, polarSmall, polar

High MW, non-polarHigh MW, non-polar

AVERAGEAVERAGE

What is the Compromise?What is the Compromise?What is the Compromise?What is the Compromise?

ABSOLUTE RECOVERIES ABSOLUTE RECOVERIES ± 4%

C18 (EC) C18 (EC) C8 (EC)C8 (EC)

89 89 91 91 75 75 8585 68 68 8989

76 8876 88

Small, polarSmall, polar

High MW, non-polarHigh MW, non-polar

AVERAGEAVERAGE

So far...So far...So far...So far...

Previous work compared C2,

C8, C18, and Phenyl where C8

found to offer a compromise

New phases synthesized

New PhasesNew PhasesNew PhasesNew Phases

Selectivity?Selectivity?Selectivity?Selectivity?

S i

O

S i

O

OH

Si ( C H2 )3 C H3

Si

O

Si

O

OH

Si ( C H2 )5 C H3

C4

C6

OC Pesticides ExtractionOC Pesticides ExtractionOC Pesticides ExtractionOC Pesticides Extraction

1. Sample pre-treatment

2. Column solvation

3. Column equilibration

4. Sample application

5. Interference elution

6. Analyte elution

HCl to pH=2, HCl to pH=2,

MeOH, 0.5%MeOH, 0.5%

55 mL mL MeOHMeOH

1010 mL water mL water

One liter in One liter in 1/21/2 hour hour

10 mL water, 10 mL water, tenten min N min N22

Two x Two x 22 mL mL Ace/EtAc 75:25 Ace/EtAc 75:25

ISOLUTE C2 ... C18ISOLUTE C2 ... C18

Recovery of OC PesticidesRecovery of OC PesticidesRecovery of OC PesticidesRecovery of OC Pesticides

C2 C4 C6 C8 C18alpha-BHC 0.0 33.3 84.8 89.8 90.8beta-BHC 0.0 54.6 100.2 95.0 96.9gama-BHC 0.0 52.9 102.0 96.0 98.9delta-BHC 0.0 36.9 95.9 105.8 105.2Heptachlor 88.2 91.9 105.8 101.0 100.6Aldrin 86.2 75.9 88.1 83.9 86.5Heptachlor epoxide 65.4 106.9 103.7 104.7 107.1Endosulfan I 59.3 107.0 107.5 107.5 106.54,4' DDE 72.4 61.9 71.3 70.0 72.8Dieldrin 88.7 103.0 106.3 105.0 107.24,4' DDD 82.3 84.1 91.8 87.0 93.54,4' DDT 79.1 69.1 83.6 82.4 85.2Methoxychlor 105.2 110.2 115.0 114.7 121.3

Avg: 56 76 97 96 98

In Conclusion...In Conclusion...In Conclusion...In Conclusion...

C6 and C8 have a unique balance of polar and non-polar interactions available.

Each may represent a potential compromise or optimal sorbent for addressing environmental problems.

ISOLUTE SPE ISOLUTE SPE SORBENTSSORBENTSISOLUTE SPE ISOLUTE SPE SORBENTSSORBENTS

Non-Polar InteractionsNon-Polar InteractionsNon-Polar InteractionsNon-Polar Interactions

Sorbents Interactions

C8

PH

C2

van der Waals

van der Waals

van der Waals

Si

Si

Si

ISOLUTE Non-Polar SorbentsISOLUTE Non-Polar SorbentsISOLUTE Non-Polar SorbentsISOLUTE Non-Polar Sorbents

C18 * OctadecylMFC18 OctadecylC8 * OctylC2 * EthylC4 ButylC6 HexylPH * PhenylCN (EC) CyanopropylCH (EC) Cyclohexyl101 PolystyreneENV+ Polystyrene * EC

Non-Polar SorbentsNon-Polar SorbentsNon-Polar SorbentsNon-Polar Sorbents

(CH2)7CH3 CH2CH3

(CH2)3CN

(CH2)17CH3

Octadecyl Octyl Ethyl

Phenyl Cyclohexyl Cyanopropyl

Polar InteractionsPolar InteractionsPolar InteractionsPolar Interactions

SorbentsSorbents InteractionsInteractions

CNCN

NHNH22

2OH2OH

Dipole / DipoleDipole / Dipole

Hydrogen-Hydrogen-BondingBonding

Hydrogen-Hydrogen-BondingBonding

OH

Si NH

H

SiN

OH

C

OSi

OH

OOH

H

ISOLUTE Polar SorbentsISOLUTE Polar SorbentsISOLUTE Polar SorbentsISOLUTE Polar Sorbents

Si SilicaFl Florisil

NH2 AminopropylPSA Primary Secondary AmineDiol 2,3-DihydroxypropylCN * Cyanopropyl

* Also available in endcapped chemistry

Used to extract polar compounds from non-aqueous

matrices (e.g. Hexane, ethyl acetate, dichloromethane, etc.)

Polar SorbentsPolar SorbentsPolar SorbentsPolar Sorbents

(CH2 )3OCH2CHCH2

HO OH

Si OH

Cyanopropyl

(CH2)3CN(CH2)3NH2

Aminopropyl

Silica Diol

NHNH22 vs. Silica Columns vs. Silica ColumnsNHNH22 vs. Silica Columns vs. Silica Columns

The use of NH2 columns in place of silica columns is strongly recommended. This is because the activity of silica columns can be affected by moisture content. IST columns are manufactured to a constant standard moisture level, so their activity will always be reliable, but adaption of literature methods using other types of silica can be problematic. Different moisture levels will affect the amount and polarity of solvents necessary for elution of the analytes. NH2 columns are recommended as they are much less susceptible to this variation.

Ionic InteractionsIonic InteractionsIonic InteractionsIonic Interactions

SorbentsSorbents InteractionsInteractions

PRSPRS

CBACBA

SAXSAX

ElectrostaticElectrostatic

ElectrostaticElectrostatic

ElectrostaticElectrostatic

H3+N

SO3-Si

Si

H3+N

O-

O

N+(CH3)3Si

-O3S

ISOLUTE Ion-Exchange ISOLUTE Ion-Exchange SorbentsSorbentsISOLUTE Ion-Exchange ISOLUTE Ion-Exchange SorbentsSorbents

Anion Exchange:Weak: NH2 Aminopropyl

PSA Primary Secondary AmineStrong: SAX Quaternary amine

PE-AX Pre-Equilibrated SAXCation exchange:Weak: CBA CarboxypropylStrong: SCX Benzenesulphonic acid

SCX-2 Propylsulphonic acidSCX-3 Ethylbenzenesulphonic acidPRS Propylsulphonic acid

Ion-Exchange SorbentsIon-Exchange SorbentsIon-Exchange SorbentsIon-Exchange Sorbents

(CH2)3NH2

Aminopropyl

(CH2 )3N+(CH3 )3

(CH2 )3SO3H

SAX (quaternary amine)

(CH2 )3COHO

CBA (carboxylic acid)

SCX (benzenesulfonic acid) PRS (propylsulfonic acid)

SO3H

ISOLUTE SCX SorbentsISOLUTE SCX SorbentsISOLUTE SCX SorbentsISOLUTE SCX Sorbents

Extending the range of strong cation exchange sorbents in the ISOLUTE range.

The range now consists of: ISOLUTE SCX – medium secondary

hydrophobic interactions ISOLUTE SCX-2 – low secondary

hydrophobic interactions ISOLUTE SCX-3 – high secondary

hydrophobic interactions

Strong Cation ExchangersStrong Cation ExchangersStrong Cation ExchangersStrong Cation Exchangers

ISOLUTE SCX Benzenesulphonic acid

ISOLUTE SCX-2 Propylsulphonic acid

ISOLUTE SCX-3 Ethyl benzenesulphonic acid