Tests of materials like, for example, sulphur (6)
I believe the answer is:
assays
'tests of materials' is the definition.
'assays' can be an answer for 'tests' (I've seen this in another clue). I am not sure about the 'of materials' bit.
'like for example sulphur' is the wordplay.
'like' becomes 'as'.
'for example' becomes 'say' ('say' can be used to introduce an example).
'sulphur' becomes 'S' (synonyms).
'as'+'say'+'s'='ASSAYS'
Can you help me to learn more?
(Other definitions for assays that I've seen before include "Does a test" , "Analyses (chemical substances)" , "Analyses of the components of metal" , "Tests ore for quality" , "Tests (a metal)" .)