Synchronous SIM/Scan Low-Level PAH Analysis Using the Agilent Technologies 6890/5975 inert GC/MSD

Význam tématu

Polynuclear Aromatic Hydrocarbons (PAHs) are persistent environmental pollutants formed during incomplete combustion of organic matter. Their widespread occurrence and potential carcinogenicity demand analytical methods capable of detecting trace levels with high confidence. Integrating both sensitive quantitation and confirmatory data in a single analysis boosts reliability in environmental monitoring and regulatory compliance.

Cíle a přehled studie / článku

This application evaluates the performance of the Agilent 6890/5975 inert GC/MSD system operated in synchronous SIM/Scan mode. The focus is on achieving linear, low-level quantitation of 16 priority PAHs over a concentration range from 0.01 ppm to 10 ppm while retaining full-scan data for compound confirmation.

Použitá metodika a instrumentace

Sample and Calibration

• Calibration standards prepared in dichloromethane from a 16-PAH stock over ten levels (0.01–10 ppm).
• Perylene-d12 internal standard and surrogates (1,3-dimethyl-2-nitrobenzene, pyrene-d10, triphenyl phosphate) at 1.0 ppm.

GC/MS Conditions

• Gas chromatograph: Agilent 6890 with inert source and pulsed splitless EPC inlet, injection volume 1 µL, inlet temperature 300 °C.
• Column: HP-5MS 30 m × 0.25 mm, film 0.25 µm, constant helium flow 1.5 mL/min, oven ramp 25 °C/min to 320 °C.
• Retention time locking to triphenyl phosphate at 10.53 min ensured reproducible retention.
• Mass spectrometer: Agilent 5975 inert with high-temperature filaments, source 300 °C, quad 180 °C, transfer line 280 °C.
• Synchronous acquisition: 12 SIM groups (3–6 ions each, 10 ms dwell) plus full-scan (45–450 amu) at 5.55 cycles/s.

Hlavní výsledky a diskuse

The system achieved excellent linearity across all 16 PAHs with an average %RSD of 6% for relative response factors from 0.01 to 10 ppm. At 0.2 ppm, both SIM and total ion chromatograms demonstrated sharp, well-resolved peaks for each analyte and internal standards. The inert source material and elevated source temperature minimized surface adsorption, improving sensitivity and peak shape. Synchronous SIM/Scan acquisition provided quantitative SIM data along with full-scan spectra for library matching and deconvolution, enabling unambiguous compound confirmation in a single run.

Přínosy a praktické využití metody

Combining trace-level detection with confirmatory full-scan data streamlines workflows in environmental and regulatory laboratories. Retention time locking eliminates frequent database updates when changing or trimming columns. The method supports rapid throughput while ensuring data integrity for PAH monitoring in water, soil, and air matrices.

Budoucí trendy a možnosti využití

Advances may include automated deconvolution software integration for broader compound screening beyond priority PAHs. Further enhancements in high-temperature filament materials and inlet designs could extend applicability to other adsorptive analytes. Coupling synchronous SIM/Scan with online sample preparation or two-dimensional GC could further increase sensitivity and selectivity.

Závěr

Synchronous SIM/Scan analysis on the Agilent 6890/5975 inert GC/MSD provides robust low-level quantitation of PAHs with linearity from 0.01 to 10 ppm, while delivering full-scan data for definitive compound confirmation. This approach enhances laboratory efficiency and analytical confidence for environmental monitoring.

Reference

1. Mike Szelewski, Full Scan Low Level Polynuclear Aromatic Hydrocarbon Analysis using the Agilent Technologies 6890/5973 inert GC/MSD, Agilent Technologies publication 5989-0264EN, 2005
2. K. Weiner, N. Mata, P. Wylie, Retention Time Locking with the G1701BA MSD Productivity ChemStation, Agilent Technologies publication 5968-3433E
3. Chin-Kai Meng, Improving Productivity with Synchronous SIM/Scan, Agilent Technologies publication 5989-3108EN
4. P. L. Wylie et al., Comprehensive Pesticide Screening by GC/MSD using Deconvolution Reporting Software, Agilent Technologies publication 5989-1157EN