GCI TECH NOTES ©

Volume 13, Number 1
A Gossman Consulting, Inc. Publication
June 2008

Hazardous Waste Analysis

Volatile and Semivolatile Organic Testing Protocol

by

David Gossman

        In 1993 we published a GC-MSD method for the analysis of volatile and semivolatile compounds in hazardous waste that continues to be referenced throughout the hazardous waste management industry, especially in the use of hazardous waste as fuels in cement kilns. Over the next few issues of GCI Tech Notes we will be presenting details of how this testing protocol can be implemented, used and improved upon. This - the first of these articles - will provide a more detailed idea of how this testing can be implemented in terms of the protocol that the analyst would use during the actual analysis of the GC-MSD data. It is important to understand the intent of this method was to provide a semiquantitative method for identifying the organic constituents in a waste stream so that a health and safety evaluation of the waste stream can be performed and so that subsequent shipment analyses can be compared with prior analyses. For this reason and to meet these generally stated data quality objectives traditional methods of quantitation and QA/QC are often unnecessary and can defeat the purpose of providing this data on a real time basis within the operating environment of a hazardous waste management facility. The details of how the data is to be used and the operating environment within which the data will be analyzed may require modification of this protocol - in some cases very significant modification. Such modifications should be consistent with the data quality objectives (DQOs) established. (DQO development guidance can be found here.)
    1. All reporting and criteria are based on relative area percents based on the total chromatographic area (not counting any extraction solvent peak). Compound specific calibrations are not required as area percent values are, most of the time, conservatively high.
    2. Except for n-hexane, straight and branched chain aliphatic hydrocarbons need not be individually identified. They can instead be reported as the approximate range of carbon numbers – for example “13% C8-C12 aliphatic hydrocarbons”. This can usually allow significant simplification for reporting of a typical waste stream since these compounds often constitute 50-100% of the smaller individual peaks found in a chromatogram.
    3. Similarly, alkyl aromatic hydrocarbons with a single benzene ring can be reported as a group, except for toluene and xylene, which must be reported separately. An example would be “5% C9-C12 alkyl aromatics”.
    4. All peaks greater than 0.1% shall be tentatively identified via computer algorithms. If the analyst confirms the identification of the peaks they will be reported based on the computer best-fit identification.
    5. For peaks constituting <1.0% if the analyst does not confirm the computer identification they may be simply reported as “unknown” so long as the total of all “unknowns” does not exceed 5% of the total chromatogram. Alternatively the analyst may identify them based on further GC/MS library research.
    6. All individual peaks constituting 1% or more of the waste sample chromatogram shall be identified initially using the computer algorithms. The analyst will review these tentative identifications and will either concur or use his/her best judgment to make a better match using the GC/MS database, fundamental mass spec data analysis or additional information (or even samples) supplied by the waste generator as needed. Waste with any peak at 1% or greater of an unknown compound will not be accepted.
    7. The above criteria apply to liquid wastes. Since the volatile and semivolatile organics compounds in solid wastes are unlikely to exceed 20% of the total, the above criteria increased by a factor of 5 may be used for all solid wastes so long as area percents of the total chromatogram are used as described above.