Standard curves and check standards can make all the difference in the successful operation of autoanalyzers and discrete anlayzers.
The importance of validating results for accuracy becomes a very important rock of consistency when operating an autoanalyzer or discrete analyzer in the hazardous field laboratory analysis environment. We are taught how to make standards and validate them with a check standard from a certified source. Routinely and tediously we daily prove our results are correct. This form of statistical certainty is the backbone of good laboratory management programs or whatever governing agency guidelines the results are analyzed for approval and compliance.
Recently, I found myself in an industrial cyanide analysis laboratory that was as about as primitive as possible while still allowing operation of highly sophisticated analyzers capable of producing accurate, valid and compliant results. Field laboratory analysis is still difficult if done properly and only successful if blessed with massive expenditure of resources, but if there are any compromises for any reasons the results produced can be highly questionable if not just plain wrong.
In this case, significant levels of cyanide were measurably found in all the containers, waters, etc. used during analysis. The laboratory was a mostly open building as well as physically attached to a gold cyanide processing plant that was also producing considerable steam, odors, and who knows what else that comes from the reaction of sodium hydroxide, potassium cyanide, gold cyanide complexes and various other ingredients from various other mineralogical analysis instruments.
At times, the fluctuations in the results were so great that I questioned the proper operation of the instrument. After acquiring multiple sources of standards and running the tried and true basic boring daily standard curve with a separate or certified check standard we were able to produce an operation procedure that tolerated the seeming highest possible contamination potential while producing absolutely accurate EPA compliant results.
When I left, the analysis was being performed daily and reliably by a less than optimally running laboratory, but with good, well defined operating procedures and strict training guidelines for all operators. Although the daily procedures seem boring and tedious they also work and produce very accurate, valid answers anywhere by anyone willing to simply follow daily procedures.