With GC-MS and LC-MS/MS analysis availability, conventional LC-MS analysis and HPLC analysis methods are hardly used for forensic drug analysis. Advanced options have left analysts confused while choosing the right platform for forensic drug analysis. Selecting an ideal method ultimately depends on your intended applications.
Today LC-MS and GC-MS are routinely used in forensic laboratories. The introduction of newer synthetic cannabinoids and designer fentanyl, GC-MS, and LC-MS systems faces new challenges every day.
Here we share some quick insights into the advantages and applications of GC-MS and LC-MS in forensic drug analysis.
GC-MS Vs. LC-MS In Forensic Drug Analysis
Comparatively, GC-MS systems are better-established techniques than LC-MS in forensic labs. LC-MS systems are more efficient for evaluating drug products in complex biological samples. Most drug products are nonvolatile and polar molecules. LC-MS systems are ideal in the assessment of such drug products. LC-MS systems don’t need derivatizing analytes for chromatographic separation.
Derivatization is compulsory in GC-MS to make the drug compounds more volatile and amenable for GC-MS analysis. If drugs are underivatized, they will usually generate peaks with reduced resolution and sensitivity.
Electrospray ionization in LC-MS systems generates intact molecular ions that enter the MS detection units. In GC-MS analysis, the generated ions may not develop apparent signals due to extensive fragmentation from ionization energy. Electron ionization generated mass spectrum can be employed across different instruments.
GC-MS systems are cheaper as they require a single quadrupole mass detector. LC-MS requires a triple quadrupole mass analyzer for better specificity. In a triple quadrupole LC-MS analysis, the initial ion is isolated, and then a collision cell fragments the ion of interest. Later the unique ion fragments are used to identify and quantitate the compound.
Despite these considerations, LC-MS faces issues with the matrix effects. In a biological sample, there are numerous other species present in the matrix that may interfere with LC-MS detection. Matric effects can generate several unnecessary changes in the assay results. Proper accountability is required to maintain the integrity of LC-MS analysis.
This is why, researchers employ isotopically labeled stable internal standards for detecting each analyte of interest. These isotopically labeled compounds are expensive, and they raise the assay costs. Without using these compounds, quantifying forensic drugs with LC-MS systems will be subject to higher errors and unreliable results.
What’s Next?
Both GC-MS and LC-MS are robust techniques used in forensic drug analysis. Getting the analysis right is the most significant aspect of forensic and legal matters. It is critical to understand that any technique used in forensic drug analysis must generate accurate and reliable information.
LC-MS has some advantages over GC-MS in the analysis of forensic drugs. Irrespective of the LC-MS technique used, LC-MS method validation and LC-MS/MS method development will be crucial for acceptance in legal and forensic communities.
The function of biotechnology and bioanalysis is to develop the correct results in analysis. It is important to treat these methods equally and to protect the sanctity of any analysis.
