Combined Compounds

Combined compounds functionality is designed to allow automatic adding of concentrations of specified compounds.  For example it could be specified that TPH ranges C6-C10, C11-C14,C15-28,C29-36 be automatically added together to give C6-36.

Compounds that are to be combined are entered into the reference table zRef_Combine_Compounds (select Import - Data Tables - zRef_Combine_Compounds to generate an import template).  The compounds to be combined are entered with the combined compound name as below.

All names must be valid names in the Chemistry Lookup Table.  Compound names that don't match can be corrected by clicking the "Get ChemCodes" button in the Import Template and assigning the correct name.  A weight can be applied to each compound if necessary.  A weight of 1 is used by default.

Compounds are added together using a multiplier for non-detects.  This can be specified under Setup - Chemistry - Post Import Calculations and Combined Compounds.

If all contributing compounds are non-detects the user can specify whether to A) use the multiplier to calculate an estimated concentration, or B) to give a non-detect of the sum of the detection limit values.

Post Import Custom Calculations

Post Import Custom Calculations are designed to provide more sophisticated calculating or updating functionality than is available using the combined compounds functionality.  They are run after every chemistry import and can be used, for example to calculate Cr (III) as a percentage of Cr(total); or to update guideline values base on the standard deviation of the results.

These calculations are distributed by ESdatCalc files, which are in xml format.  They can be opened in Notepad, or any other text editor.  The actual calculation must be a valid SQL statement.  This statement can be constructed using Access (Update or Append queries), or SQL Server Management Studio.  The SQL generated is copied directly into the ESdatCalc file.  Alternatively, a request can be submitted to ESdat Support.