Polar Lipids in Starch-Rich Commodities to be Analyzed with LC-MS-Based Metabolomics-Optimization of Ionization Parameters and High-Throughput Extraction Protocols.
Christin ClaassenJürgen KuballaSascha RohnPublished in: Metabolites (2019)
Metabolomics-based approaches are still receiving growing attention with regard to food authenticity testing. Such studies require enormous sample numbers with negligible experimental or analytical variations to obtain statistically reliable results. In this context, an extraction protocol in line with optimized ionization parameters was developed in consideration of potential starch-derived matrix effects focusing on the polar lipids of potatoes. Therefore, well-known extractions (Bligh and Dyer, Folch, Matyash, and a n-hexane-based procedure) were compared in a non-targeted and a targeted approach regarding the extractability of their lipids such as phosphatidylcholines, phosphatidylethanolamines, galacto- and glucocerebrosides, di- and triglycerides, and acylated steryl glucosides. The selected Folch method was also scrutinized in view of its ability to remove the matrix's starch and consequently improved by substituting trichlormethane with ethyl acetate as a "greener" Folch approach. Moreover, the challenge of starch-derived contamination and imminent ion suppression in the electrospray ionization source (ESI) was addressed by an optimization of ionization parameters varying desolvation settings, removing injection peaks, and increasing the angles and distances of the ESI-device. Long-term stability tests over five days were performed successfully with a combination of appropriate extraction and decreased desolvation settings during ionization. In conclusion, the present methodology provided the basis for on-going large-scale metabolomic studies with respect to the botanical origin of potatoes using UPLC-IMS-QToF (ultra-high performance liquid chromatography ion mobility spectroscopy quadrupole-time of flight mass spectrometer).
Keyphrases
- gas chromatography
- tandem mass spectrometry
- ultra high performance liquid chromatography
- mass spectrometry
- ms ms
- liquid chromatography
- high resolution mass spectrometry
- simultaneous determination
- high resolution
- high performance liquid chromatography
- high throughput
- solid phase extraction
- ionic liquid
- cancer therapy
- human health
- fatty acid
- case control
- lactic acid
- randomized controlled trial
- risk assessment
- minimally invasive
- working memory
- drinking water
- drug delivery
- biofilm formation
- pseudomonas aeruginosa
- cystic fibrosis
- staphylococcus aureus
- ultrasound guided
- climate change