To measure PCBs or TCE in environmental samples, which technique is typically required?

To measure PCBs or TCE in environmental samples, which technique is typically required?

• A. GC alone
• B. HPLC
• C. GC/MS
• D. Mass spectrometry not used

Answer: (C)

Measuring PCBs and TCE in environmental samples needs both effective separation and reliable identification in complex mixtures. Gas chromatography provides excellent separation for these volatile and semi‑volatile organics, but it’s not enough on its own because many compounds can co‑elute or produce ambiguous signals. Mass spectrometry adds highly selective, sensitive detection that can identify and quantify individual PCB congeners and confirm the presence of TCE by its unique mass spectrum. This combination—GC to separate and MS to identify/quantify—is the standard approach in environmental analysis, making GC/MS the best choice. GC alone can miss or misidentify compounds, HPLC is less suited for these volatiles, and mass spectrometry is not used is incorrect in this context.

Measuring PCBs and TCE in environmental samples needs both effective separation and reliable identification in complex mixtures. Gas chromatography provides excellent separation for these volatile and semi‑volatile organics, but it’s not enough on its own because many compounds can co‑elute or produce ambiguous signals. Mass spectrometry adds highly selective, sensitive detection that can identify and quantify individual PCB congeners and confirm the presence of TCE by its unique mass spectrum. This combination—GC to separate and MS to identify/quantify—is the standard approach in environmental analysis, making GC/MS the best choice. GC alone can miss or misidentify compounds, HPLC is less suited for these volatiles, and mass spectrometry is not used is incorrect in this context.