Analysis of nitroaromatic compounds in complex samples using solid-phase microextraction and isotope dilution...

Area of Science:

• Environmental Chemistry
• Analytical Chemistry

Background:

• Nitroaromatic compounds from explosives and pharmaceuticals can contaminate water.
• Sensitive detection methods are needed for environmental monitoring.

Purpose of the Study:

• To optimize a solid-phase microextraction (SPME) method for analyzing nitroaromatic compounds.
• To compare SPME with solid-phase extraction (SPE) for sensitivity and efficiency.

Main Methods:

• Gas chromatography-electron-capture negative ionisation mass spectrometry (GC-ECNI-MS) with isotope dilution quantification.
• Optimization of SPME parameters for water-based samples.
• Comparison of SPME and SPE performance.

Main Results:

• Electron-capture negative ionisation (ECNI) proved most sensitive and selective for ionization.
• SPME demonstrated higher sensitivity than SPE for small sample volumes.
• Achieved limit of detections (LODs) for SPME were 0.02-38 ng/L, significantly lower than SPE's 6-184 ng/L.
• The optimized SPME method was successfully applied to real-world samples at ng/L levels.

Conclusions:

• The developed SPME-GC-ECNI-MS method is highly sensitive and selective for nitroaromatic compound analysis in complex water matrices.
• SPME is a superior technique to SPE for the trace analysis of these compounds in small volumes.
• This method is effective for monitoring environmental samples, such as those from artificial reed beds treated with sludge.