1. GreenChemistryImplementationatthe ChicagoRegional Laboratory
Cyanide sample preparation: Switchedtomicrodistillationin2006 saving244mL sulfuricacid
persample due to the decrease insample size.
Solidphase extractionforpesticidesand PCBs: For preparingwatersamplesforanalysis by
method8080 and 8081. A differentextractiontechnique saves450mLof methylenechloride
persample. Implementedin2005.
Solidphase extractionforoil andgrease: Forthe analysisof watersamplesusingmethod1664,
a differentextractiontechniquesaves165mL hexane persample. Implementedin2007.
Replaced the use of metallicmercurywithcoppermetal forthe treatmentof organicsolvent
extractsto remove sulfur. Sulfurisaninterference inthe chromatographyof pesticidesand
PCBs. Metallicmercuryisexpensivetopurchase anddispose of. The replacementcopperstrips
are re-useable, eliminatingthe needtodispose of them. Implementedin2006.
Ionchromatography (IC) methodimprovements: Several ICMethods have beenimprovedby
installingeluentgeneratorsthatreduce the amountof chemical reagents consumed inthese
chromatographytechniques. Implementedin2009, eluentgenerationsavesone-halfof the
reagentandcuts the chemical waste bythe same amount.
More efficientautosamplers wereinstalledonall metalsanalysisinstruments,savingone-half
the acid washcycle volume onthese instruments. One half the waste isalsogenerated.
Implementedin 2010
Directmercuryanalyzershave replacedcold-vaporatomicabsorptioninstrumentsforRCRA and
Superfundsample analysis. Implementedin2012, DMA reducesthe waste generatedby98%
and requiresnochemical reagents.
Newmercurywateranalyzers save between55% and65% of the waste generatedandreagent
usedpersample. Instrumentsinstalledin2011.
Acceleratedsolventextraction (ASE) forsoil andsedimentsamples: Similartothe savingsfor
watersample extractionusingsolidphase extraction,ASE saves200mL methylene chloride per
sample. Implementedin2004.
Replace heliumwithhydrogenasacarrier gas inpesticide andPCBanalyses. Heliumis
expensive andbecomingmore difficulttoacquire due tolimitedsupplies/suppliers. Hydrogen

2. can be generatedatthe pointof use and doesnotrequire a cryogenicstorage systemlike
heliumdoes. Savesthe energyusedtoseparate andstore the helium.
Installed2newmetalsinstrumentsrequiringalowerflow rate of non-renewable Argongasat
13L per minute vs.15L/minute duringinstrumentoperation. The cryogenicgas,argonisneeded
lessoften,savingthe energyrequiredtoseparate itandstore it for shipping. These new metals
instrumentshave more stable opticsandelectronics,requiringthe use of achillertocool the
instrumentsonlyduringoperationratherthan24/7 like the instrumentsthatwere replaced.
Implementedin2013.
Installedcoldwaterrecirculatingpumps foruse duringliquid-liquidextractions in2011. The
extractionshave torun for18 hours witha cold watercondensertocool the extractionsolvent.
Coldtap waterwas usedpriorto this,butpressure leakswouldperiodicallyoccur,leaving
massive puddlesof waterwhenlefttorunovernight. The water use isnow limitedtothe
capacityof the recirculatingpump,around10 gallons.
Discrete analyzersreplacedsegmentedflow automatedanalyzersfor 7 differentcolorimetric
tests. One discrete analyzerreplaced4segmentedflowdevices andoperates using1/100th
the
sample size,reagentsandwaste generation. Implementedin2008.
A particle size analyzerwasinstalledin2009 to replace grainsize determinationsusingsieve-
shakers. The particle size analyzeruses1gram vs.150 grams of soil or sediment,leavingno
waste.
SubstitutedaircalibrationforBODmeasurementsforthe sodiumazide reagentrecommended
inthe waste waterregulatory method. Sodiumazide isahazardousmaterial. 2010
implementation.
CRL plansto substitute the dichromate reagentinthe Chemical OxygenDemandmethodwitha
lesshazardousreagentin2013. Dichromate reagentisa hazardousmaterial.
The Karl Fischerreagentusedinwatercontentdeterminationsispyridine. CRLplansto replace
thishazardousreagentin2013 witha non-hazardoussubstitute.
CRL periodicallyupdatesitssamplecontainerrequirements,including reduced sample size,that
fieldinspectorsreference duringtheirsamplingeventplanning. The CRL sample coordinator
suppliesthisinformationtopotential fieldinspectors. These updatesare usuallydue to
instrumentandmethodimprovementsmade byCRLchemists.