Recent Developments in Environmental Contaminant Monitoring

Recent Developments in Environmental Contaminant

Monitoring

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Topics in Environmental Contaminant Monitoring

• Radiello passive air sampling products• BPE/DNPH for simultaneous measurement of ozone

and carbonyls • Supelclean Sulfoxide for monitoring PCBs in Oil• Dioxin Prep System• Supelpak 2 (purified XAD-2)• Mercury sampling tubes• Deactivated Thermal

Desorption Tube

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Radiello Passive Sampling ProductsPassive air samplers and accessories for industrial hygiene and air monitoringUnique ‘Radial Symmetry Design’ offers higher capacity and faster uptake rates

than traditional passive monitorsFeature BenefitHigh uptake rates Faster samplingMinimal reverse diffusion Uptake rates constant/more reproducible

Higher accuracy of resultsHigh capacity Broader sampling rangeStiff diffusive wall & high tolerance More reproducible uptake ratesTortuosity of diffusive path Uptake rate invariable to air speedUptake rate measured in controlled atmospheric chamber

Uptake rate very precise

Water repellent diffusive body Amenable to bad weatherAdsorbents undergo complex conditioning and QC

Blanks are 3-times lower than instrument noise

Low detection limits + high uptake rates + high capacity

Sampling can range from 15 min – 30 days (1 ppb – 1000 ppm)

Reusable hardware components Only cartridges need to be purchased for subsequent samples, economical

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Q = uptake rate = D•S/lD = diffusion coefficientS = diffusive surfaceI = diffusive pathK = S/l = geometrical constant of sampler (diff. surface/diff. path)m = adsorbed analyte massC = analyte concentrationt = exposure time

Principle of Operation

•Fick’s Law: (Q = D•K)

ClSD

tm

Q

tQmC

K

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Principle of Operation (cont’d)

• Cylindrical diffusive surface• Diffusive surface is larger than the adsorbing surface• Small sorbent volume • Short distance between the diffusive and adsorbing surfaces

• Microporous polyethylene diffusive material• Consistent, high sampling rate• High surface area

SEM of the microporous sintered polyethylene diffusive barrier of radiello. The path length is much longer than the barrier thickness due to the tortuosity of the pores.

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Radiello Sampling Rate Comparison

• Diffusive sampling rate for benzene on activated charcoal/chemical desorption (25 °C)

Adsorbing Surface

Diffusive Surface

Axial Sampler Radial Sampler

Q = 7-8 mL/min. Q = 80 mL/min.

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Sampling Rate Q

• Specific to compound• Specific to sampler• Values given by manufacturer (radiello® Manual & datasheet)

• Temperature dependent (correction equation in the manual)

Given Q rates are corrected for desorption efficiencies

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Calibration Aids for Radiello

• Pre spiked cartridges for calibration and proficiency testing

Available for • BTEX (Chem. Des.)

• BTEX (Thermal Des.)

• VOCs (Chem. Des.)

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Radiello System Components

•Adsorbing cartridge•Diffusive body•Supporting plate•Adhesive label with bar code indication

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Sampling Protocol: To Start the Sampling

(1) Open the plastic bag, draw the adsorbent cartridge out from the tube and put it in the diffusive body. The lower part of the diffusive body holds a seat for the central positioning of the cartridge (right).

(2) Keeping the diffusive body in a vertical position, screw it onto the supporting plate

(3) Insert a label in the pocket without peeling it off

(4) Place assembled device on worker or location to be monitored.Keep note of the date and time and expose radiello.Sampling has started!

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Sampling Protocol: Post-Sampling and Analysis

(1) Keep note of the date and time of the end of exposure. Place the cartridge into the tube, peel off the label and stick it onto the tube such that the barcode is parallel to the axis of the tube

(2) Analytes are desorbed from the radiello tube using either solvent desorption (CS2, CH3CN, etc.) or thermal desorption. Spent cartridges are discarded. (Thermal desorption cartridges can be reused.)

HPLC chromatogram of aldehydes following solvent desorption from a radiello tube

Complete analytical protocols for each analyte class are supplied in the radiello Manual.

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Radiello Sampling System in Action

• Radiello is versatile and suited for nearly all sampling environments

Personnel monitoring (travels with the worker)

Environmental monitoring (e.g.exhaust fumes)

Workspace (stationary) monitoring

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Radiello Applications

Compound class Adsorbent Analysis Method

Anaesthetic gases Adsorbed on act. charcoal/mol. sieves Chromatography

Phenols thermal des. Tenax TA Chromatography

Ammonia Chemisorption on phosphoric acid Photometry

HCl Adsorption on silica gel Ion chromatography

O3 Chemisorption on 4,4’-Dipyridylethylene Photometry

H2S Chemisorption on zinc acetate Photometry

VOCs/BTEX thermal des. Graphitised carbon Chromatography

NO2/SO2/HF Chemisorption on TEA Photom. / IC / Ion Sel. Electrode

Aldehydes Chemisorption on 2,4-DNPH Chromatography

VOCs/BTEX CS2 chem. des. Activated charcoal Chromatography

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• Radiello Passive air sampling products• BPE/DNPH for simultaneous measurement of

ozone and carbonyls• Supelclean Sulfoxide for monitoring PCBs in Oil• Dioxin Prep System• Supelpak 2 (purified XAD-2)• Mercury sampling tubes• Deactivated Thermal Desorption Tube

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BPE/DNPH Cartridge

• Simultaneous measurement of ozone and aldehydes in ambient air• Integrated ozone scrubber

• No extra/leaking connections• Not effected by high humidity• Low background levels

Trans-1,2-Bis(2-pyridyl)ethylene (BPE)

2,4-Dinitrophenylhydrazine (DNPH)

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BPE/DNPH Reaction & Analysis

O-

O+

O

Ozone

NH

N+

O-

O

N+

O-

O

NH2

2,4-Dinitrophenylhydrazine (DNPH)

N+

O-

O

N+

O-

O

NHN R2

R1

Carbonyl 2,4-dinitrophenylhydrazone

O

R1

R1

Carbonyls

OH2

+

+

BPE-silica

DNPH-silica

OH OH+

H+

+

OH2

Pyridine-2-aldehyde (PA)H

N

O

trans-1,2-Bis(2-pyridyl)ethylene (BPE)

N

N

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Analyte Concentrations under Different Ambient Conditions

• The advantages of the BPE ozone scrubber of the traditional KI scrubber and DNPH alone are shown here

Analyte:Climate: Sunny Rainy Sunny Rainy Sunny Rainy Sunny RainyDNPH n.a. n.a. 4.1 3.0 2.2 2.9 2.6 3.1KI + DNPH n.a. n.a. 5.0 1.8 2.8 1.2 3.4 1.6BPE-DNPH 41.9 15.6 5.2 3.8 2.9 3.2 3.5 3.3

Ozone Formaldehyde Acetaldehyde Acetone

Aldehyde and ketone concentration under different climate conditionsConcentration units are µg/m3, air samples from Chiba City, Japan, June-July 2007

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• Radiello Passive air sampling products• BPE/DNPH for simultaneous measurement of ozone

and carbonyls • Supelclean Sulfoxide for monitoring PCBs in Oil• Dioxin Prep System• Supelpak 2 (purified XAD-2)• Mercury sampling tubes• Deactivated Thermal Desorption Tube

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Supelclean Sulfoxide SPE for PCBs in Oil

• For the extraction of PCBs from transformer, waste and mineral oil.

• Many techniques are available (sulfuric acid extraction, LLE (with ACN or DMSO), and SPE (florisil and silica)); but the best technique is LLE with DMSO

• Difficult to separate hydrocarbon interferences with PCBs

• Japan needs to analyze > 300k oil samples w/ detection limit of </= 0.5 ppm

SiO2 NH2NH

O

S

O

Cl+

_

PCB retention is facilitated via interaction between the SPE phase’s electrophilic sulfur atom and the -electron cloud formed from

aromatic rings inherent with PCBs

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Supelclean Sulfoxide SPE Procedure

Sample Pre-TreatmentDilute oil sample 1:1 (v/v) with hexane and spike sample with internal standard, PCB congener-13C (0.5 ppm)

Condition/Equilibration Condition SPE phase with 20 mL acetone (to remove residual moisture); and equilibrate with 40 mL of hexane

Sample LoadLayer 250 uL of pre-treated sample (from step 1) onto the upper frit of the SPE tube. Rinse the inner wall of the SPE tube, 2 x 0.5 mL hexane to further drive the oil sample into the packed bed.

WashOnce the hexane solvent (applied in step 3) has cleared the upper frit of the packed bed, wash the SPE tube with 11 mL hexane (for GC-HRMS) or 12 mL hexane (for GC-QMS).

Elution Upon complete elution of the hexane wash solvent (step 4), elute PCBs with 25 mL hexane and collect for analysis.

Evaporation/Reconstitution Evaporate 25 mL eluate containing PCBs under nitrogen, and adjust to 250 µL with hexane.

Analysis GC-HRMS or GC-QMS

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Analysis of Spiked Oil Sample

Prepared using

Supelclean Sulfoxide

10 20 30Time (min)

10 20 30Time (min)

Prepared by hexane

dilution/H2SO4 extraction

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Dioxin Prep System

• Dioxins & PCBs = Persistent Organic Pollutants• Covers a wide range of halogenated aromatic cmpds. (PCDDs

(PCDFs)• Formed as a result of incomplete combustion of hydrocarbons in

the presence of chlorine e.g. metal processing, domestic waste incineration, etc.

• Bio-accumulate due to lipophillic nature• Emissions into environ & food chain strictly controlled by WHO• Samples Tested = food stuffs (fish & fish feed, soil, water, etc.)

7-layers of acid and base treated silica optimized to remove: Unsaturated hydrocarbons, phthalates, organochlorides, pigments, PAHs, lipids, proteins, phenols, sulfur, pesticides, etc.

Dual Layer Carbon reversible tube:

• Isolates and concentrates coplanar PCBs, Dioxins, Furans

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AgNO3(10%) 3g

Carboxen 1016100mg

Carboxen 1000100mg

Multi-layer21267-U

Dual-layer21239-U

Screw joint

Silica gel 0.9ｇ

Glass filter

Screw joint

Silica gel

KOH(2%) 3g

H2SO4(44%) 4.5g

H2SO4(22%) 6g

Stopcock

Silver nitrate layer removessulfur compounds

Sulfuric acid layers oxidize/ remove organic interferences

Potassium hydroxide layer removes acidic compounds

Dioxins and coplanar PCBscollect on carbon layers

Sample Clean-up Using Multi-layer Silica Gel Column and Dual-layer Carbon Tube

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Sample Collection

Extraction

Clean-up

Fractionation

GC/HRMS

• XAD-2 (stack gas)• Polyurethane foam (PUF) (air)• C18 disk, Carbopack C (water)

• Sulfuric acid wash• Multi-layer silica gel column

• Alumina, carbon, florisil, or carbon impregnated silica column

• GC capillary columns (SP-2331, SPB-Octyl, Equity-5, MDN-5S)

• Stack gas from incinerators• Waste water/river water, soil/sediment• Air

Dioxin Analysis Basic Steps – JIS Methods

com

bine

d

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Supelpak-2 Purified XAD-2 Resins

• Supelpak-2• Cleaned to meet and exceed US EPA

criteria for purity as outlined in Level I Environmental Assessment Procedures Manual.

• Supelpak-2B• Cleaned to meet and exceed US EPA

requirements for PCBs in water according to the Great Lakes National Program Office (GLNPO).

• Supelpak-2SV• Specially cleaned and tested for optimal

performance in the capture and extraction of semivolatile organic compounds.

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Environmental Methods Using XAD-2 Resins

• Methods using XAD-2 resin traps:

Method Description0010 SW-846 method for semi-volatile compounds including PCBs and PAHs

0023A SW-846 method for dioxins and furans23 40CFR Part 60 Appendix A method for dioxins and furans

CARB 428 California Air Resources Board method for dioxins, furans and PCBsCARB 429 California Air Resources Board method for PAHs

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Mercury Sampling Tubes

Partnership with Frontier GeoSciences Inc.Specialty treated charcoal used for sampling Hg in stack gases (EPA 324)Supelco manufactures the tubes, and Frontier GeoSciences Inc. performs the analysis using cold vapor atomic fluorescence spectrometry

Combines 3 core competencies: carbons, carbon coating, tube packing

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Deactivated Thermal Desorption Tube

Diffusive Sampling CapBrass End Cap

Tube Dimensions: 6.35 mm O.D. x 5 mm I.D. x 89 mm Long

Deactivated SS Tube

Sampling Inlet

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Summary

• Radiello Passive air sampling products http://www.sigma-aldrich.com/radiello

• BPE/DNPH for simultaneous measurement of ozone and carbonyls http://www.sigma-aldrich.com/spe

• Supelclean Sulfoxide for monitoring PCBs in Oil http://tinyurl.com/sulfoxidespe

• Dioxin Prep System http://www.sigma-aldrich.com/dioxin

• Supelpak 2 (purified XAD-2) http://www.sigma-aldrich.com/sampleprep

• Mercury sampling tubes http://tinyurl.com/mercurytubes

• Passivated Thermal Tubes / Carbopack X http://tinyurl.com/carbopackx

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Acknowledgements/Collaborators

• Danillo Cottica, FSM (Radiello)• Shigehisa Uchiyama, Japan National Institute of Public Health• Toshiro Kaneko, Sigma-Aldrich Japan• Frontier Geosciences (Mercury tubes)• Supelco R&D Teams

For more information on the subjects presented here, please contact [email protected] or

your regional sales team.

Recent Developments in Environmental Contaminant Monitoring

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