Improved sample preparation method for selected persistent organochlorine pollutants in human serum using solid-phase...

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Toxicology

Background:

• Persistent organochlorine pollutants (POPs) pose risks to human health.
• Accurate quantification of POPs in biological matrices like human serum is crucial for exposure assessment.
• Existing extraction methods for POPs in serum can be time-consuming and may result in interfering substances.

Purpose of the Study:

• To develop and validate an improved solid-phase extraction (SPE) method for isolating trace levels of POPs in human serum.
• To enhance analytical throughput and matrix cleanliness for subsequent GC-MS or GC-ECD analysis.
• To achieve consistent and reliable recovery rates for various organochlorine pesticides and polychlorinated biphenyls.

Main Methods:

• Serum protein denaturation using formic acid.
• Solid-phase extraction using C18 Empore disk cartridges.
• Lipid interference elimination via sulfuric acid wash of the eluate.
• Quantification using Gas Chromatography-Mass Spectrometry (GC-MS) in Selected Ion Monitoring (SIM) mode or Gas Chromatography-Electron Capture Detector (GC-ECD).

Main Results:

• The developed SPE method demonstrated improved assay throughput and a cleaner analytical matrix compared to prior techniques.
• Consistent recoveries were achieved across three fortification levels using 13C12 PCB 149 as an internal standard.
• Recovery rates ranged from 48% to 140% for organochlorine pesticides and 71% to 126% for polychlorinated biphenyls.

Conclusions:

• The improved SPE method is effective for isolating and concentrating trace POPs in human serum.
• This method provides a cleaner matrix and higher throughput, making it suitable for routine toxicological analysis.
• The validated method ensures reliable quantification of organochlorine pesticides and PCBs in human serum samples.