Ill. Admin. Code tit. 50, § 9140.50
a) Request to Test a Split Specimen
c) Procedural Requirements for the Laboratory Testing the Primary Specimen
1) The first laboratory at which the primary and split specimen arrive must check to see whether the split specimen is available for testing. If the split specimen is unavailable or appears insufficient, the laboratory must do the following:
d) Procedural Requirements for the Laboratory Testing the Split Specimen
1) Testing of a Split Specimen When it is Tested to Reconfirm the Presence of Alcohol, Drugs or Other Intoxicating Compounds
2) Testing of a Split Specimen When it is Tested to Reconfirm an Adulterated Test Result