Fully automatable two-dimensional hydrophilic interaction liquid chromatography-reversed phase liquid chromatography with online tandem mass spectrometry for shotgun proteomics

Abstract A rapid and accurate method using reversed-phase liquid chromatography–tandem mass spectrometry interfaced with electrospray was developed for determination of acrylamide in cooked food samples. A simplified sample treatment procedure using an extraction step with acidified water without cleanup was developed. A C18 column with an aqueous formic acid–methanol mixture as the mobile phase was used under isocratic conditions. The method was validated in-house for robustness, limits of detection (LOD) and quantitation (LOQ), linearity, recovery, and accuracy both on standard and baked-product and potato flour matrixes. Good results in the low ppb level were obtained for LOD (<15 μg/kg) and LOQ (<25 μg/kg) of acrylamide in samples. Excellent linearity (r 2 = 0.999–1.000) was established over 2 orders of magnitude by performing statistical tests. The absence of both constant and proportional systematic errors demonstrated good method accuracy. Excellent results were obtained for intraday repeatability (RSD < 1.5%) and between-day precision (RSD < 5%). Extraction recoveries from food products were calculated in the 97 ± 3–99 ± 2% (n = 6) range with a labeled internal standard (13C3-acrylamide). The applicability of the method to determination of acrylamide in cooked food products was demonstrated.

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Comparison of Online Comprehensive HILIC × RP and RP × RP with Trapping Modulation Coupled to Mass Spectrometry for Microalgae Peptidomics

Separations ◽

10.3390/separations7020025 ◽

2020 ◽

Vol 7 (2) ◽

pp. 25 ◽

Cited By ~ 1

Author(s):

Eduardo Sommella ◽

Emanuela Salviati ◽

Simona Musella ◽

Veronica Di Sarno ◽

Francesco Gasparrini ◽

...

Keyword(s):

Mass Spectrometry ◽

Liquid Chromatography ◽

Tandem Mass Spectrometry ◽

Peptide Mapping ◽

Reversed Phase ◽

Peak Capacity ◽

Tandem Mass ◽

Two Dimensional ◽

Mass Spectrometry Detection ◽

Hydrophilic Interaction

In this work, two online comprehensive two-dimensional liquid chromatography platforms, namely Hydrophilic interaction liquid chromatography × Reversed phase (HILIC × RP) and Reversed phase × Reversed Phase (RP × RP) coupled to mass spectrometry, were compared for the analysis of complex peptide samples. In the first dimension, a HILIC Amide and C18 Bioshell peptide (150 × 2.1 mm, 1.7 and 2.0 μm) columns were selected, while, in the second dimension, a short C18 (50 × 3.0 mm, 2.7 μm) Bioshell peptide column was used. Two C18 trapping columns (10 × 3.0 mm, 1.9 μm), characterized by high retention and surface area, were employed as modulation interface in both HILIC × RP and RP × RP methods. The LC × LC platforms were coupled to UV and tandem mass spectrometry detection and tested for the separation and identification of two gastro-intestinal digests of commercial microalgae formulations (Spirulina Platensis and Klamath). Their performances were evaluated in terms of peak capacity, maximum number and properties of identified phycocyanin peptides. Our results showed that the HILIC × RP approach provided the highest peak capacity values (nc HILIC × RP: 932 vs. nc RP × RP: 701) with an analysis time of 60 min, while the RP × RP approach was able to identify a slight higher number of phycocyanin derived peptides (HILIC × RP: 88 vs. RP × RP: 103). These results point out the flexibility and potential of HILIC × RP and RP × RP based on trapping modulation for peptide mapping approaches.

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