Environmental Engineering Reference
In-Depth Information
11
Traps, Mistakes, and Errors
Alfred R.Conklin, Jr., and Rolf Meinholtz
Traps, mistakes, and errors can occur at any stage in sampling and analysis; for example,
in the field, during transport and storage, during analysis, and in the interpretation and
communication of analytical results. Traps occur when incomplete data about a sampling
activity, including the history and characteristics of a field, have been collected or
something unusual happens. Mistakes often are the result of untrained or inexperienced
personnel who do not understand the procedure, the importance of each step, how it
works, and what results are reasonable and expected. Mistakes could also be made by
personnel who simply do not pay attention to what they are doing.
Most traps, mistakes, and errors associated with environmental sampling occur with
the physical sampling process as it occurs in the field. Fewer occur during transport and
analysis, and the least with chemical and statistical analysis and reporting of data. In
some cases errors are caused by the heterogeneous nature of the environment. In most
cases they are caused by personnel [1]. Unfortunately nothing will completely eliminate
errors and mistakes, but they can be minimized by having checks at each stage of the
process, by having good communication between samplers and laboratory personnel, and
by using statistical tools. To be effective these must be carried out with careful attention
to detail.
The first place in which personnel have trouble is in reading maps and judging
distances. A way around these problems is the extensive use of a global positioning
system (GPS). The second place in which problems occur is in transporting and storing
samples. The thoughtful use of chain of custody forms and procedures will minimize
problems associated with these activities. The third place will be in carrying out the
analysis, and the last in reporting the results. Extensive and continuing training in
analytical procedures and reporting protocols will minimize these problems. Good
communication between personnel involved at each stage is also crucial in minimizing
errors.
During transportation and storage, problems arise due to mixing samples and putting
the wrong paperwork in the sample transport box, along with breakage and the loss of
temperature control. Carefully choosing sample containers and packing materials, paying
attention to details in completing paperwork, including labeling, and including the correct
paperwork with the proper samples will all go a long way toward minimizing problems.
Checks and double checks at this point can prevent the loss of samples and incorrect
laboratory analysis.
In the analytical process there are also a number of traps and errors that can be made.
Samples may be extracted using the wrong extractant, or the correct extractant might be
used but with the wrong instrument. Interfering compounds or species present in the
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