Liquid chromatography–mass spectrometry for C60 fullerene analysis: optimisation and comparison of three ionisation techniques

Abstract

The increasing use and production of nanomaterials have led to growing concern over the release of new pollutants to the environment. Fullerenes have been a subject of intense research, both because of their unique chemistry and because of technological applications. The development of analytical methods to quantify the fullerenes in complex sample matrices is a crucial step in the study of their occurrence and exposure, and thus in risk assessment. This paper reports the development and optimisation of a method combining liquid chromatography with ion-trap mass spectrometry (LC-ITMS) for analysis of the fullerene C(60). Under the optimised chromatogram conditions, a C(18) analytical column had good selectivity for fullerenes C(60) and C(70), with retention times of 3.0 and 4.1 min, respectively. Mass spectrometric detection was tested and optimised using three common ionisation techniques-atmospheric-pressure chemical ionisation (APCI), atmospheric-pressure photoionisation (APPI), and electrospray ionisation (ESI). The molecular ion was most abundant for C (60) (-) (m/z=720) in APCI and APPI, whereas adduct ions were formed with the molecular ion in ESI. Finally, the performance of the three ionisation techniques examined was compared by use of five validation criteria. The instrument detection limit (8 ng mL(-1)), quantification limit (27 ng mL(-1)), detection sensitivity (90.2 ng mL(-1)), linear range (8-1,000 ng mL(-1)), and repeatability (15 %) of APPI make it the most promising ionisation technique for fullerene C(60) analysis.

Recent developments in atmospheric pressure photoionization‐mass spectrometry

“…Development of analysis methods for fullerenes from complex biological or environmental matrices has become increasingly important in their risk assessment. Negative‐ion APPI has been applied for the analysis of fullerenes with better performance than ESI or APCI (Li et al, ). Fullerenes have positive EAs and form efficiently negative molecular ions by electron capture.…”

Determination of several fullerenes in sewage water by LC HR-MS using atmospheric pressure photoionisation

“…Depending on Environmental Science: Nano Paper the HPLC stationary phase, they can be added to the mobile phase (reversed phase) or post-column (normal phase). The ESI process induces the complex adduct formation 32 with the inconveniences previously stated. 8,17 This unfavourable behaviour hinders the process of qualifying and quantifying.…”

Characterisation and determination of fullerenes: A critical review

“…[145,146] has also been reported. Núñez et al [144] studied and characterised the cluster ions present in the MS spectra of fullerenes at m/z M+16 and m/z M+32 by tandem MS, HRMS and accurate mass measurements using an…”