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IR, WATER 3 HAZARDOUS WASTE LABORATt-... CERTIFIED b DEPT o. .�� y CALIFORNIA EALTH SERVICES SAMPLING AND ANALYTICAS CONSIDERATIONS are highly complex mixtures of hydrocarbons which often contain more than a hundred identifiable components. Gosolines are characterized by their lower boiling range and by their aliphatic and aromatic hydrocarbon distributions. These, to5ether With the presence or absence of lecd and ethylene dibromide and/Or F,thylene dichloride serve to distinguish between leaded and unleaded gasolin,. CENTRAL COAST ANALYTICAL SERVICES, INC., has modern instrumentation which con separate and simultaneously identify the type of fuel, the c.-ount present, and the BTS: . Further, ethylbenzene. ethylene dibromide and ethylene aichloride, which are added to leaded gasoline, ore also separated and '4uontotively Identified. CENTRAL COAST ANALYTICAL SERVICES, INC., provides septum sealed vials free of charge to clients interested in collecting their own groundwater samples for fuel fingerprint analysis. Those vials contain an ASTM-approved preservative which adjusts the pH to 2 In order to block biodegradation which ion otherwise be a ver;' serious factor. Soils are best sampled using metallic Shelby tubes or brass rings and then covering ,hu ends of the tubes with Teflon sheeting prior, to emplacing a snugly-fitting plastic cop. The whole care is frozen or refrigerated the field. Once in the laboratory, subnomples may be removed and analyzed by a variation of tho, purge-and-trap gas chromatographic technique. Although it is unlikely that significant loss takes place if the samples are frozen, tie holding time for volatile cor+pounds in sail is 14 Bays from time of sampling until the time the eomple is analyzed. wgter samples are collected by completely filling the vials, sealing, checking r bubbles and refilling and resealing if bubbles ore present, then placing the filled viols into plastic guard bottles which contain activated charcoal. The guord bottles which contain the charcoal ore refrigerated (NOT FR02EN) in the field. Analysis is performed using EPA Method 524.2 and compared to standards containing appropriate fuels and volatile Friority Pollutants. 4Ihsn free product is available, some Of that should be sampled and submitted in a septum-sealed viol which is then placed in a guard bottle. The laboratory should be instructed to use the free product for the standard used to quantitate the fuel in the samples. During the initial stages of an investigation, it is recommended that sompleq be taken at several depths to groundwater. If it is unclear whether or not groundwater has been contaminated, we recommend drilling be 'Stopped if strong petroleum odors aro encountered. In the later stages of an investigation. drilling-=mer be continued in such cases PROVIDED that precoutions are taken to ensure that contomincticn will not follow the path of the drill as it passes through the contaminated sone. Overaampling followed by selected sample on-2lysis is recommended. This strategy allows the laboratory to zteo in on meaningful samples while avoiding costly resampling. CENTRAL COAST ANALYTICAL SERVICES, INC. employs both flome iOnixation (FID) gov chromatography and selected ion GC/MS to obtain fuel fingerprints. We prefer the Iatter since it gives information about the distribution of aliphatic and aromatic hydrocarbons which is not +available by i Page 5 CENTRAL COAST ANALYTICAL SERVICES Son Luis obispO. California (805)543-2553 w _cam`