While most analytes in forensic applications analyze well with positive ionization, there are analytes that show better ionization efficiency with negative ionization, for example, acidic compounds. These analytes include ethanol metabolites such as ethyl glucuronide (ETG), ethyl sulfate (ETS), and the barbiturates such as amobarbital, butabarbital, butalbital, pentobarbital, phenobarbital, and secobarbital.

In this technical note, researchers demonstrated a method to simultaneously analyze ethanol metabolites and barbiturates in human urine using QTRAP®/Triple Quad 4500 LC-MS/MS system. Sample preparation is based on a simple “dilute and shoot” methodology. The method has a total runtime of 5 minutes, shows good sensitivity and is very robust. More than 800 continuous injections of human urine samples were performed on a single LC column with no deterioration in performance evident.

How does this test play out in real-world scenarios? ETG and ETS are biomarkers for determining the presence of alcohol over the past 80 hours where ETG is the direct metabolite of alcohol. ETG is only detected if alcohol has been consumed. What is more is that urine tests are the most common and inexpensive choice when testing for drug use and can be easily captured. Making sure results stand up in court, but also being able to run simultaneous drug screenings will help your lab keep up with sample workloads while also producing reliable results.