Yes, custom fields text fields in the product stoichiometry tables can be added the samples table, the fields need to have exact same names and type.
Solution: To add the the custom field to the samples table follow these steps:
1.Log into Signals Notebook as an Administrator
2.Open 'Configuration'
3.Navigate to 'System Objects' > ‘Samples’
4.Create the property:
4.1.Under 'Sample Settings' select 'Properties'
4.2.Click 'Add Property'
4.3.In the 'Create Samples Property' page fill the form as follows:
4.3.1.Field Name: <custom name>
4.3.2.Field Type: Text
4.3.3.Click 'Add New Property'
5.Add the property to the template:
5.1.Under 'Sample Settings' select 'Templates'
5.2.Click on 'Chemical Sample'
5.3.In the 'Add Property' text field at the bottom type <custom name>
5.4.Select the '<custom name> (Text)' from the dropdown menu
5.5.Click 'Update'