What is the FDA consensus standard or industry standard for checking for residues?
The FDA does not give any guidance on preferred methods for detecting residues. For investigations they prefer selective methods such as high performance liquid chromatography (HPLC), but they certainly accept the use of non-selective methods such as total organic carbon (TOC), see this page from the Center for Drug Evaluation and Research. In our experience, in medical device residue detection, the most commonly used technique is TOC, at least as far as detergent residues are concerned. The Technical Information Reports (TIR-12 and TIR-30) from the AAMI gives some references to methods used for specific types of residues other than detergents.
The technical experts at Alconox, Inc have taken the guess work out of selecting the appropriate analytical detection methods for all of its brands. To review the Directory of cleaner residue detection methods for each Alconox detergent visit Alconox.com.