Measurement of Acrylonitrile Measurement of Acrylonitrile in Ambient Airin Ambient Air

AMTACAMTACApril 12, 2011April 12, 2011

John BricarelloJohn BricarelloCalifornia Air Resources BoardCalifornia Air Resources Board

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RequirementsRequirements

Need to find alternate to 910 samplerNeed to find alternate to 910 samplerCannot pass air through an instrument prior Cannot pass air through an instrument prior

to capturing the acrylonitrileto capturing the acrylonitrileMust be more sensitive than current method Must be more sensitive than current method

(MLD066 RL = 0.3 ppb)(MLD066 RL = 0.3 ppb)Must be able to deploy a sampler without Must be able to deploy a sampler without

too much disruption to field personneltoo much disruption to field personnel

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Where we left off May 2009Where we left off May 2009

Select appropriate sorbent materialSelect appropriate sorbent materialFinalize instrumental methodFinalize instrumental methodSelect sampler for sorbent tubesSelect sampler for sorbent tubesEstablish sampling protocol with low flow Establish sampling protocol with low flow

pumppumpTest designed methodology and generate Test designed methodology and generate

resultsresultsMove final methodology to fieldMove final methodology to field

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Solid SorbentSolid SorbentCarboxen 1000Carboxen 1000

AdvantagesAdvantagesGood reproducibility for standardsGood reproducibility for standardsLow trap desorption temperature, few artifactsLow trap desorption temperature, few artifactsCan be used more than 200 timesCan be used more than 200 timesHandles low sampling flows over 24 hour periodHandles low sampling flows over 24 hour periodDetection ‘on tube’ <0.05ngDetection ‘on tube’ <0.05ng

DisadvantagesDisadvantagesAdvertised as hydrophobic, it still retains a significant Advertised as hydrophobic, it still retains a significant

amount of wateramount of waterDesigned for C2 – C5 molecules it retains up to C10 Designed for C2 – C5 molecules it retains up to C10

organics both polar and non-polarorganics both polar and non-polar

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InstrumentationInstrumentation

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Sampling and ProblemsSampling and Problems

StartupStartupBattery operated personal pump equipped with four tube Battery operated personal pump equipped with four tube

holderholderOne sample tube, three spiked tubesOne sample tube, three spiked tubesBattery operated – did not last 24 hoursBattery operated – did not last 24 hoursFair recovery with inside air, very poor recovery in Fair recovery with inside air, very poor recovery in

outside airoutside airWater in air interfered with retention of acrylonitrileWater in air interfered with retention of acrylonitrileTheorized that pressure drop across sorbent tube led to Theorized that pressure drop across sorbent tube led to

water condensationwater condensation

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Sampler Version 1Sampler Version 1

Quad Manifold

Tube Heater

Variac

Heater Controller

PumpTubes

Clips

Heater

88

Sampler Version 2Sampler Version 2

Figure 1 Figure 2 Figure 3

Figure 4Figure 5

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MLD’s Roof Top Monitoring Platform MLD’s Roof Top Monitoring Platform ResultsResults

Average Median Maximum Minimum

Result, ppt 2.4 2.5 8.2 0.7

Recovery, % 66 70 102 21

Correl. Coeff. 0.9973 0.9988 1.000 0.9816

Average of all >300ppt (60 in Million cancer risk) canister results = 590ppt

0123456789

Date Sample Started

Acry

lon

itri

le p

pt

AN Conc. 1 in Million

1010

Typical Acrylonitrile MS OutputTypical Acrylonitrile MS OutputTypical TIC of Sample containing methanol

Extracted Ion Chromatogram of Standards, Sample & Spikes

1111

AcroleinAcrolein

TestingTestingAdded acrolein to acrylonitrile standardsAdded acrolein to acrylonitrile standards

IssuesIssuesStability of acrolein in canisters compared to Stability of acrolein in canisters compared to

acrylonitrileacrylonitrileAlternate methodologyAlternate methodology

The follow slide shows acrylonitrile - acrolein The follow slide shows acrylonitrile - acrolein comparisoncomparison

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Acrolein Results MLD RoofAcrolein Results MLD Roof ACN Acrolein

ppt ppt

Avg. 5.5 223

Med. 4.6 182

Max. 22.5 978

Min. 1.1 65

Rec.avg 78% 57%

All Monitoring Sites

Avg. 590 680

n= 2197 3894

n: > 300ppt results

4560 total measurements

Acrylonitrile vs. AcroleinAcrolein=concentration/20

0.0

10.0

20.0

30.0

40.0

50.0

60.0

11/8

/201

0

11/1

5/20

10

11/2

2/20

10

11/2

9/20

10

12/6

/201

0

12/1

3/20

10

12/2

0/20

10

12/2

7/20

10

1/3/

2011

1/10

/201

1

1/17

/201

1

1/24

/201

1

1/31

/201

1

2/7/

2011

2/14

/201

1

2/21

/201

1

2/28

/201

1

3/7/

2011

3/14

/201

1

3/21

/201

1

3/28

/201

1

4/4/

2011

Date

Con

cent

ratio

n, p

pt

Acrylonitrile (ACN) Acrolein

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Observations and Other Anecdotal Observations and Other Anecdotal InformationInformation

Passivated Carboxen 1000 Passivated Carboxen 1000 Fiberglass epoxy enclosure caused Fiberglass epoxy enclosure caused

interferencesinterferencesPVC led to elevated acrylonitrile levelsPVC led to elevated acrylonitrile levelsSampler influences resultSampler influences resultHigher results on calm days than windy daysHigher results on calm days than windy daysTubes need to be heated all the timeTubes need to be heated all the time

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What is ComingWhat is Coming

Develop Sampler version 3Develop Sampler version 3Deploy sampler to selected sitesDeploy sampler to selected sitesFinalize analytical SOP for acrylonitrile and Finalize analytical SOP for acrylonitrile and

possibly acroleinpossibly acroleinCompare site dataCompare site dataDetermine shipping, sampling and receiving Determine shipping, sampling and receiving

logisticslogisticsDeploy to all network sites if feasibleDeploy to all network sites if feasible

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ContactContact

John Bricarello, APSJohn Bricarello, APS

California Air Resources BoardCalifornia Air Resources Board

Monitoring and Laboratory DivisionMonitoring and Laboratory Division

jbricare@arb.ca.gov

(916) 327-2336(916) 327-2336