ENVIRONMENTAL ANALYSIS I. Solid Phase Extraction SPE sorbents

SORBENT SELECTION

Which Sorbent? EPA analytes ä OC / OP / ON-pesticides ä PCBs ä PAHs ä Phthalates

Analyte Properties OCH 2 COOH Cl 2,4 D Benzo [b] fluoranthene Heptachlor 2 CCl Cl

InstrumentationInstrumentation v Tekmar AutoTrace SPE workstation v HP 5890 GC w MSD v IST Isolute SPE columns

The Method: EPA Sample pre-treatment 2. Column solvation 3. Column equilibration 4. Sample application 5. Interference elution 6. Analyte elution Na 2 SO 3, HCl to pH=2, IPA wetting agent 10 mL IPA 10 mL water One liter in 1/2 hour 10 mL water, one min N 2 Two x 2 mL Ace/EtAc 75:25 60 minutes for ten samples

A Data Snapshot | COMPOUNDREP 1REP 2REP 3AVGRSD 1hexachlorocyclopentadiene dimethylphthalate acenaphthalene acenaphthene-d10IS 52-chlorobiphenyl diethylphthalate fluorene ,3-dichlorobiphenyl hexachlorobenzene simazine atrazine pentachlorophenolND 13lindane phenanthrene-d10IS 15phenanthrene anthracene ,4,5-trichlorobiphenyl alachlor heptachlor di-n-butylphthalate ,2',4,4'-tetrachlorobiphenyl aldrin heptachlor epoxide ,2',3',4,6-pentachlorobiphenyl gamma-chlordane pyrene alpha-chlordane trans nonachlor ,2',4,4',5,6'-hexachlorobiphenyl endrin butylbenzylphthalate di(2-ethylhexyl)adipate benz[a]anthracene chrysene d-12IS 35chrysene ,2'3,3',4,4',6-heptachlorobiphenyl methoxychlor ,2',3,3',4,5',6,6'-octachlorobenzene di(2-ethylhexyl)phthalate benzo[b]fluoranthene benzo[k]fluoranthene benzo[a]pyrene perylene-d indeno[1,2,3,c,d]pyrene dibenz[a,h]anthracene benzo[g,h,i]perylene

Reducing the Data 39di(2-ethylhexyl)phthalate benzo[b]fluoranthene benzo[k]fluoranthene benzo[a]pyrene perylene-d indeno[1,2,3,c,d]pyrene dibenz[a,h]anthracene benzo[g,h,i]perylene OVERALL: 88 EARLY: 91 MID: 85 LATE: 89

Bonded Silica Surface Si O Si O Si O Si O Si O Si Si O Si O Si OH Si OH OH OH C18C8C2PhenylC18C8C2Phenyl

Sorbent Screening C2C8C18PH

Which Sorbent? ELUTION VOLUME: mL CONDITIONING: IPA SOLVENT: Acetone / EtAc 75:25 ABSOLUTE RECOVERIES ABSOLUTE RECOVERIES ± 4% C18 (EC) C18 (EC) C2 Phenyl 1g 1/2 g 1 g 1 g 1g 1/2 g 1 g 1 g SORBENT TYPE Small, polar High MW, non-polar AVERAGE

What is the Compromise? ABSOLUTE RECOVERIES ABSOLUTE RECOVERIES ± 4% C18 (EC) C8 (EC) Small, polar High MW, non-polar AVERAGE

So far... v Previous work compared C2, C8, C18, and Phenyl where C8 found to offer a compromise v New phases synthesized

New Phases Selectivity?Selectivity? Si O Si O OH Si(CH 2 ) 3 CH 3 Si O Si O Si(CH 2 ) 5 CH 3 C4 C6

OC 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, MeOH, 0.5% 5 mL MeOH 10 mL water One liter in 1/2 hour 10 mL water, ten min N 2 Two x 2 mL Ace/EtAc 75:25 ISOLUTE C2... C18

Recovery of OC Pesticides C2 C4 C6 C8 C18 alpha-BHC beta-BHC gama-BHC delta-BHC Heptachlor Aldrin Heptachlor epoxide Endosulfan I ,4' DDE Dieldrin ,4' DDD ,4' DDT Methoxychlor Avg:

In Conclusion... v C6 and C8 have a unique balance of polar and non-polar interactions available. v Each may represent a potential compromise or optimal sorbent for addressing environmental problems.

ISOLUTE SPE SORBENTS

Non-Polar Interactions SorbentsInteractions C8 PH C2 van der Waals Si

ISOLUTE Non-Polar Sorbents C18 * Octadecyl MFC18 Octadecyl C8 * Octyl C2 * Ethyl C4Butyl C6Hexyl PH * Phenyl CN (EC) Cyanopropyl CH (EC) Cyclohexyl 101Polystyrene ENV+Polystyrene* EC

Non-Polar Sorbents (CH 2 ) 7 CH 3 CH 2 CH 3 (CH 2 ) 3 CN (CH 2 ) 17 CH 3 OctadecylOctylEthyl PhenylCyclohexylCyanopropyl

Polar Interactions Sorbents Interactions CN NH 2 2OH Dipole / Dipole Hydrogen-Bonding Hydrogen-Bonding O H Si N H H N O H C O O H OO H H

ISOLUTE Polar Sorbents SiSilica FlFlorisil NH 2 Aminopropyl PSAPrimary Secondary Amine Diol2,3-Dihydroxypropyl CN *Cyanopropyl * Also available in endcapped chemistry Used to extract polar compounds from non-aqueous matrices (e.g. Hexane, ethyl acetate, dichloromethane, etc.)

Polar Sorbents (CH 2 ) 3 OCH 2 CHCH 2 HOOH SiOH Cyanopropyl (CH 2 ) 3 CN(CH 2 ) 3 NH 2 Aminopropyl SilicaDiol

NH 2 vs. Silica Columns The use of NH 2 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. NH 2 columns are recommended as they are much less susceptible to this variation.

Ionic Interactions SorbentsInteractions PRS CBA SAX Electrostatic Electrostatic Electrostatic H 3 + N SO 3 - Si H 3 + N O - O N + (CH 3 ) 3 Si - O 3 S

ISOLUTE Ion-Exchange Sorbents Anion Exchange: Weak: NH 2 Aminopropyl PSA Primary Secondary Amine Strong: SAX Quaternary amine PE-AX Pre-Equilibrated SAX Cation exchange: Weak: CBA Carboxypropyl Strong: SCX Benzenesulphonic acid SCX-2 Propylsulphonic acid SCX-3 Ethylbenzenesulphonic acid PRS Propylsulphonic acid

Ion-Exchange Sorbents (CH 2 ) 3 NH 2 Aminopropyl (CH 2 ) 3 N + (CH 3 ) 3 (CH 2 ) 3 SO 3 H SAX (quaternary amine) (CH 2 ) 3 COH O CBA (carboxylic acid) SCX (benzenesulfonic acid)PRS (propylsulfonic acid) SO 3 H

ISOLUTE SCX Sorbents v Extending the range of strong cation exchange sorbents in the ISOLUTE range. v The range now consists of: ä ISOLUTE SCX – medium secondary hydrophobic interactions ä ISOLUTE SCX-2 – low secondary hydrophobic interactions ä ISOLUTE SCX-3 – high secondary hydrophobic interactions

Strong Cation Exchangers ISOLUTE SCX Benzenesulphonic acid ISOLUTE SCX-2 Propylsulphonic acid ISOLUTE SCX-3 Ethyl benzenesulphonic acid