1. Department of Forensic Science, College of Criminal Justice, Sam Houston State University , 1003 Bowers Blvd, Box 2525 Huntsville, TX 77341, USA
2. Quest Diagnostics Nichols Institute , Toxicology Department, 14225 Newbrook Drive, Chantilly, VA 20151, USA
3. Drug Testing Consultations, LLC St. Louis, MO 63122, USA
4. Edinboro Consulting, LLC , Glen Allen, VA 23060, USA