Is there any guidance offered for meeting the QC criteria in Lachat Quickchem methods?

Document ID

Document ID TE6749

Published Date

Published Date 27/05/2017
Question
Is there any guidance offered for meeting the QC criteria in Lachat Quickchem methods?
Summary
QC requirements for Lachat Quickchem methods
 
Answer
There is a clean water act rule in prepublication.  It is signed and any changes made before publication would be minor.  It clarifies a couple of Quality Control (QC) topics which the USEPA frequently recieves questions on.

“For clarification purposes, the following two lines have been added to the methods modification paragraph (b):
 
Where the laboratory is using a vendor-supplied method, it is the QC criteria in the reference method, not the vendor's method that must be met to show equivalency.
 
Where a sample preparation step is required (i.e., digestion, distillation), QC tests are to be run using standards treated in the same way as samples”.