Page 63 - Grapevine NovDec 2021

Around The Vineyard

Figure 1: Part of a 2019 Government lake water
analysis report for the vineyard industry. Most
industrial chemists would reject it outright. The
number of decimal places to the last number indi-
cate the lower detection limit of the instrument
used and the ‘<’ sign is like a flashing hazard light
to question the analysis precision and its worth to
you.

Figure 2 is the type of analysis that an instru-
ment like the ICP-OES that I used can give. It can
reach detection levels by a factor of 100 to 1,000
lower than a basic ICP. In this case the difference
between the detection limit of 5 decimal places in
cadmium and chromium with 6 decimal places was
the quality of the standards used to calibrate the
instrument on a daily basis. Analytical standards
can vary batch to batch.

Figure 2: Analysis
from an ICP-OES
adds more decimal
places making it
more accurate and
useful for better
understanding of
actual water chem-
istry.

Why is it important for vineyards to have the
most accurate and precise analysis of their waters?
Just like in metallurgy and metal standards, trace
amounts of elements can have large impacts on
chemical and physical characteristics.

The analysis report in Figure 1 lists iron compo-

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