Occasionally labs may issue the same compound with a different ChemCode.  This results in the compounds being treated in ESdat as two compounds (the concept being one ChemCode per compound).

This can be addressed either by filtering and editing the ChemCode to a single standard one and removing the unwanted one from the zRef_Chemistry_Lookup table, or by using the Consolidate ChemCode function

If you are using ESdat Desktop in conjunction with ESdat Server the latter is recommended for global changes across all projects/sites, and is done through the Server interface.

If you are using ESdat Desktop with local Access databases it is done through the Setup - Chemistry menu.