Presampling - Field Sampling: Principles and Practices in Environmental Analysis - page 74

Many restrictions apply to shipping dangerous or toxic compounds. All applicable
safety precautions, signage, and other shipping restrictions must be followed when
shipping samples to an analytical laboratory.
3.12. CHAIN OF CUSTODY
From obtaining a sample through the final analytical procedure applied to it, a chain of
custody must be kept. This is a trail or list of where the sample has been, who has
handled it and how, the length of time it was stored, and its transportation route. This
information must be meticulously recorded and maintained because it provides proof of
the authenticity of the sample. It also helps in preventing contamination of the sample, or
if analysis indicates that something untoward has happened between sampling and
analysis the chain of custody, can shed light on where and when this might have
happened. Chain of custody forms may be available from the commercial laboratory that
is to analyze the samples. More information about the chain of custody will be given in
Chapters 8 and 10.
3.13. ANALYTICAL LABORATORY AND PROCEDURES
Samples will be analyzed at two locations for one or many components. Analysis that
must be carried out immediately will be performed in the field or at the field office
laboratory discussed above. Samples needing more detailed or sophisticated analysis will
be sent to a commercial laboratory. At the commercial laboratory samples will be treated
appropriately for the analysis of the component of interest.
An analytical laboratory needs to be decided upon and at the same time the types of
components the laboratory will be asked to analyze for need to be decided. The
commercial laboratory will have a project manager assigned to the project. This person
will help in making decisions about various aspects of sampling, sample handling,
shipping, and the analytical methods needed to obtain the desired information. Often the
analytical laboratory will have special kits with appropriate sample containers and
shipping boxes, which may vary, depending on the type of analysis to be done. They may
also specify the conditions such as temperature needed during storage and transport.
These details are further discussed in Chapters 8 and 10.
The question then becomes what components in the sample are important. The first
most important division is between organic and inorganic. Samples to be analyzed for
inorganic components are obtained and handled differently from samples intended for the
analysis of organic components. As noted above the metal composition of the sampler
will be important in obtaining samples to be analyzed for inorganic components,
particularly metals. Samples to be analyzed for organic components must be handled in
such a way as to minimize the loss of organic compounds.
If the laboratory does not have sample shipping kits, discuss with them how the
samples should be handled. Along with this goes deciding on a numbering system for
samples and setting up the chain of custody, which must be decided upon and well