Post-ICP Chemical Ionization MS for Total Extractable Organic Fluorine Quantitation

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Mass Spectrometry

Background:

• Accurate quantitation of total extractable organic fluorine (EOF) is crucial for comprehensive chemical analysis.
• The increasing prevalence of perfluoroalkyl substances necessitates robust methods for EOF determination due to diverse chemical forms and limited standards.

Purpose of the Study:

• To evaluate post-plasma chemical ionization mass spectrometry (MS) as a method for total EOF quantitation.
• To optimize ICP operating parameters and sample introduction for enhanced fluorine detection.

Main Methods:

• Organofluorine samples were introduced into an inductively coupled plasma (ICP), forming HF, which was then ionized and detected by MS.
• A single-pass spray chamber was used to mitigate volatility biases, enabling compound-independent response factors.
• Food contact paper products were analyzed after methanolic extraction, preconcentration, and flow injection analysis.

Main Results:

• Optimal ICP parameters were identified for robust ion generation and fluorine detection.
• An instrumental detection limit of 2.2 ng F mL⁻¹ was achieved, significantly better than ICP-MS.
• Organic fluorine was detected in all tested food contact paper products, with levels ranging from 22-363 ng F cm⁻².

Conclusions:

• Post-ICP chemical ionization MS provides a facile and sensitive technique for total EOF quantitation.
• This method expands elemental MS capabilities for fluorine analysis, particularly for complex samples.