GEN-MKT-18-7897-A
Feb 16, 2017 | Blogs, Forensic | 0 comments
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.
Finding the right information shouldn’t slow you down. Whether you’re troubleshooting your mass spec, learning something new, or optimizing performance, access to the right resources at the right moment makes all the difference.
As an analytical strategy, middle-down mass spectrometry (MS) workflows characterize biotherapeutic proteins by analyzing large, digested protein fragments or defined subunits, rather than fully intact proteins (top-down) or digested peptides (bottom-up). A middle-down strategy combines the strengths of top-down and bottom-up approaches by delivering high sequence coverage and structural specificity while maintaining relatively simple sample preparation. In practice, middle-down analysis enables accurate mass measurement, rapid sequence confirmation, and localization of key post-translational modifications (PTMs) on protein subunits that are directly relevant to product quality.
In biopharmaceutical development, sequence variants (SV) are considered an inherent risk of producing complex proteins in living systems. Sequence variants are unintended changes to the amino acid sequence of a biotherapeutic and can be caused by errors in transcription or translation in the host cell, or cell culture and process conditions. Detailed analysis of SVs is important in process and product development to ensure the drug’s safety and efficacy. Even low‑level sequence variants can have significant implications for product quality, safety, and efficacy, making their accurate detection and characterization a critical requirement across development, process optimization, and regulatory submission.
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