Response to EPA Comments: RCRA Facility Investigation Phase I ...

x^ene isomers (as well as die lA3-trichloropropane) were not analytes that required
reporting for this job in eitfaerflie proposal or woric plan tiie data was not reviewed by myself. I
would like to state diat there has been an internal memonoulum seat to all employees of Target
diatno GC/MS data is to leave our hdxntoiy without my review and signature.
• Regarding the spike recovecy perfoimed n EQB2MS and why it was not spiked with the analytes
of coocem:
Targetfollows EPA Mediod 8260 protocol as closely as possible for the analysis of soil gas.
Since EPA Medwd 8260 st^gests the use of tbe following analytes (Section 5.13 Mediod
8260A. September 1994):
1,1 -Dichloroethene
Benzene
TVichlnoediylene
Toluene
Chlorobenzene
EPA suggests diis suite of compounds because dieir physiochemical propeidee cover the wide
range of analytes analyzed by using Mediod 8260. We have utilized otber MS/MSD compounds
on odier wortseopeawfaai it is specified in the work plan. We havefound dtrough oqpeiience
that it is extreme^ important to follow tbe letter of die cmtract and not pofocm die analytical
tedmiqae wiOi a variation unless it iz written in the work plan and has been signed o£f by the
ctieot I fidly agree diat using die compounds of intecect is a good ahenative, however, you
must realize dud a spiking experiment, especially in soil gas, is limited by the experiment The
matrix intn-ftrences inherent in a given sanqile matrix based upco die lengdi of time die
contaminant is in contact widi die matrix and physical limitations such as die electron sharing
dmni ^ pi bonding with tbe soil matrix, the interaction of moisture around the molecular species
preventing afEective analyte transfer into the analytical equipment, and numerous other t^iysical
parameters in effect in the actual sample matxix are not accounted for in any spiking experimflnt
fhatta: 410-992-6622 9180 Rumsty Md. Columbia, AfD 21045 fax : 410-992^347
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