Quantitative Analysis of an Antioxidant Additive in Insoluble Plastics by Surface-Assisted Laser Desorption/Ionization Mass Spectrometry (SALDI-MS) Using TiO2 Nanoparticles

Abstract

The applicability of matrix-free surface-assisted laser desorption/ionization mass spectrometry using porous silicon (DIOS-MS) and TiO2 nanoparticles (TiO2-SALDI-MS) was examined by analyzing an antioxidant added to insoluble polypropylene (PP) materials. The optimized solvent extraction, which involved freezing and crushing the PP, results in a good recovery, 89ῌ4 and 97ῌ8῍ for 0.5 wt῍ of the added antioxidant, tetrakis[methylene3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane (commercial name; Irganox1010) in laboratory-produced and commercial PP composites, respectively. The positive ion measurements in DIOS and TiO2-SALDI-MS yielded sodium adduct ions without any interference from other signals. Using an internal standard with a similar structure, a good calibration curve linearity was established in the Irganox1010 concentration range of 0.01῍2.0 mg/mL in PP, which was su$cient for monitoring the plastic additives. However, TiO2-SALDI-MS was superior to DIOS-MS in terms of mass resolution and easiness of sample preparation. A solvent extraction method followed by TiO2-SALDI-MS appears to be a anticipated method for the analysis of additives in insoluble plastics.

Atmospheric Pressure Plasma-Treated Carbon Nanowalls’ Surface-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (CNW-SALDI-MS)

“…To solve these drawbacks, matrix-free, surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) is a matrix-free photo-desorption/ionization method, first reported in 1995 by Sunner et al [2] and reviewed elsewhere [3][4][5][6]. Inorganic nanoparticles or nanostructured surfaces (nanostructures or nanoparticles of platinum [7][8][9][10][11], titanium or titania [12][13][14][15][16][17], iron oxides [18,19], silver [20], silicon [21,22], etc.) were reported to use them as SALDI substrates [23][24][25][26][27][28].…”

Revisiting the quantitative features of surface-assisted laser desorption/ionization mass spectrometric analysis

“…Ag NP-based SALDI-MS has been used in the quantitative analysis of small biomolecules [25,26]. Metal oxide NPs such as Fe 3 O 4 magnetic NPs (MNPs) [27] and TiO 2 NPs [28][29][30][31] are also useful SALDI-assisting materials owing to their absorption capacity toward the laser light used in SALDI-MS. They also possess the feature of ease of surface functionalization.…”

A novel type of matrix for surface-assisted laser desorption–ionization mass spectrometric detection of biomolecules using metal-organic frameworks

“…presence of "sweet spots"), which are associated to some serious background interference at the low mass region (<500 Da) and poor shot-to-shot reproducibility. As a result, this would make the quantitative analysis of small saccharide molecules very difficult [13]. On account of these drawbacks and limitations, surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) [14,15] has been introduced that uses nanoparticles and nanostructured materials as matrices.…”