In my previous blog, I discussed how your laboratory measurements could be precise (the results are reproducible), yet inaccurate (the value is wrong).
It is comparable to my target results from archery practice where I had consistency shooting at a particular area of the target (-performing good lab technique and producing similar values each trial), however, I was not hitting the bullseye (i.e, achieving the correct concentration).
There are probably many more reasons why precision may be good but accuracy is off for your analytical measurements.
Build in checks and balances to ensure that your next project can identify these errors before you use and rely on the data for your litigation cases.
One of the best ways to do this is provide a sample where the concentration of the target analyses is known. Standard reference materials are available for most matrices from many different sources. NIST is a good place to start. If there isn’t an SRM available, you may need to make your own… but that is a story for another blog.