Characterization and liquid chromatography-MS/MS based quantification of hydroxylated fullerenes

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Nanomaterials Science

Background:

• Highly water-soluble hydroxylated fullerene derivatives (fullerols) are used in various commercial products.
• Potential cytotoxicity necessitates their environmental monitoring.
• Current analytical methods lack sensitivity for sub-ppm quantification in environmental matrices.

Purpose of the Study:

• Develop and compare liquid chromatography-ultraviolet/visible spectroscopy (LC-UV/vis) and LC-mass spectrometry (LC-MS) methods.
• Quantify commercial fullerols in environmental samples at sub-ppm levels.
• Assess method robustness against common environmental organic matter.

Main Methods:

• Utilized amide-type hydrophilic interaction liquid chromatography (HILIC) for separation.
• Employed UV/Vis spectroscopy and various LC-MS detection modes (Q1 scan, MI, MRM).
• Tested method performance with Suvanee River fulvic acids (SRFA) as a matrix interferent.

Main Results:

• Achieved excellent separation efficiency (plate number >2000) with 90% acetonitrile mobile phase.
• Method detection limits (MDLs) ranged from 42.8 ng/mL (UV) to 0.19 pg/mL (LC-MS/MRM).
• LC-MS/MI and LC-MS/MRM showed significantly lower interference from SRFA (2.5% error) compared to UV and Q1 scan methods.

Conclusions:

• Developed the first robust MS-based quantification method for water-soluble fullerene derivatives.
• LC-MS, particularly using Multiple Ion Monitoring (MI) or Multiple Reaction Monitoring (MRM), is suitable for environmental analysis.
• These methods enable broader implementation of MS for fullerol and other water-soluble fullerene derivative detection in environmental samples.