An Overview of Basic Principles of Analytical Methods - Field Sampling: Principles and Practices in Environmental Analysis - page 258

note the loss and resample.
10.5. DOCUMENTATION
As already stated, it is vital that the sample field analysis, project notebook, field
calibration, field information, and the COC forms be filled out completely, and in “real
time”. (See Chapter 8 for considerations of the completion of COC sample labeling and
documentation.) It is very difficult to remember all the details in a sampling event while
dealing with the sample containers, test equipment, coolers, and all the other associated
paraphernalia. To expect to remember all the details correctly and record them later is the
height of folly. This folly can have a vast impact on the samples, the data obtained from
them, and the final results of the analysis due to field data or sample mislabeling errors.
Figure 10.2 is an example of a field calibration sheet for recording analyses such as pH,
conductivity, turbidity, and dissolved oxygen. Figures 10.3 and 10.4 are field information
sheets and COC record sheets. The field information form (Figure 10.3) and the project
notebook are the places in which anything and everything about the field can and should
be recorded.
10.6. SAMPLE PREPARATION FOR ANALYSIS
Sample preparation before analysis can range from simple to very complex. A drinking
water sample for volatile organic compound analysis might only require the addition of
internal and surrogate reference compounds before being introduced into an instrument
for analysis. Sample preparation for a more complex sample matrix such as a clayey soil
might require grinding, mixing, and subsequent extraction using an organic solvent that
produces a concentrated extract for analysis. Preparation might also entail the extraction
of the original sample into an organic solvent, this solvent being subsequently extracted
with a different solvent that is compatible with the instrument to be used for analysis.
Other cases will involve the separation of different fractions of soil or of immiscible
liquid fractions and their subsequent separate analysis. The results of the separate
analysis are combined on a proportional basis to yield a result representative of the whole
original sample. While these are all based on the principles of general chemistry, the
specific steps used or performed on the sample are usually specified by a regulatory or
government agency that provides the laboratory's certifications and license. (See Ref. 3.)
10.7. ANALYTICAL TESTING
Generally speaking, the natural laws of chemistry and physics serve as the basis for an
analytical method. Natural laws are those such as the absorption of a specific wavelength
of energy, be it visible, infrared, or ultraviolet, by a specific chemical element or
compound. It could also be the ability of a specific chemical compound to be precipitated
out of a solution using a specific chemical reaction and subsequently the product being