tain the compound from the matrix to
quantify it. If the extraction is flawed,
the potential for false-negative results increases. Extraction techniques include
liquid-solid extraction and liquid-liquid
extraction; the selection of the method
will depend on the type of product and
the nature of the suspected contaminant.
If immunoaffinity columns are used, it is
essential to handle and store them properly since many systems require refrigerated storage of the columns to maintain
bound for the export market, laboratories that produce results with international recognition may be needed.
at the parts-per-trillion range and the
sampling, extraction and analytical procedures were appropriate, then the finding may not be toxicologically relevant
and no further action will be required. In
this case, risk communication will be essential to address consumers’ concerns
and quell their outrage.
Seeking Laboratory Assistance
In many cases, the internal laboratory
will not have the analytical capabilities
to look for an unknown, suspected contaminant. If the contamination is related
to a single incident, the investment in
analytical capacity probably is not
worthwhile. In this case, it is important
to find a laboratory that is willing to
work with you and help you work
through the sampling issues and identification of the unknown compound.
When selecting a laboratory, the first
question should be whether it has ever
analyzed samples of the food and the
contaminant in question. Obviously, if
the laboratory is accredited for that particular analysis, then the process will be
easier. ISO/IEC 17025 accreditation
specifically addresses a laboratory’s ability to produce precise and accurate analytical results. Accreditation processes
have specific criteria to determine not
only the laboratory’s competence in a
particular analysis but also the overall
management and quality control
processes that include the technical competency of personnel, validity and appropriateness of the methods, the
traceability of measurements to national
standards, the suitability, calibration and
maintenance of equipment, the appropriateness of the testing environment
and the adequacy of quality assurance
and quality control procedures. An accredited laboratory will be able to help
you identify and quantify the contaminant even without prior experience in
analyzing the unknown compound.
If the contaminant is regulated and a
maximum limit has been established, it
is important to consider the regulatory
requirements for testing. For products
Prepare for the Unexpected!