Standard addition strip for quantitative electrostatic spray ionization mass spectrometry analysis: determination of caffeine in drinks.

Talanta

Laboratoire d׳Electrochimie Physique et Analytique, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015 Lausanne, Switzerland. Electronic address:

Published: December 2014

Standard addition strips were prepared for the quantitative determination of caffeine in different beverages by electrostatic spray ionization mass spectrometry (ESTASI-MS). The gist of this approach is to dry spots of caffeine solutions with different concentrations on a polymer strip, then to deposit a drop of sample mixed with an internal standard, here theobromine on each spot and to measure the mass spectrometry signals of caffeine and theobromine by ESTASI-MS. This strip approach is very convenient and provides quantitative analyses as accurate as the classical standard addition method by MS or liquid chromatography.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.talanta.2014.07.024DOI Listing

Publication Analysis

Top Keywords

standard addition
12
mass spectrometry
12
electrostatic spray
8
spray ionization
8
ionization mass
8
determination caffeine
8
standard
4
addition strip
4
strip quantitative
4
quantitative electrostatic
4

Similar Publications

α-Synuclein interaction with POPC/POPS vesicles.

Soft Matter

January 2025

Physical Chemistry, Chemistry Centre, Lund University, SE-22100 Lund, Sweden.

We have investigated the adsorption of the amyloid-forming protein α-Synuclein (αSyn) onto small unilamellar vesicles composed of a mixture of zwitterionic POPC and anionic POPS lipids. αSyn monomers adsorb onto the anionic lipid vesicles where they adopt an α-helical secondary structure. The degree of adsorption depends on the fraction of anionic lipid in the mixed lipid membrane, but one needs to consider the electrostatic shift of the serine p with increasing fraction of POPS.

View Article and Find Full Text PDF

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV)-associated cancer, and immune checkpoint inhibitors (ICIs) have shown efficacy in its treatment. The combination of chemotherapy and ICIs represents a new trend in the standard care for metastatic NPC. In this study, we aim to clarify the immune cell profile and related prognostic factors in the ICI-based treatment of metastatic NPC.

View Article and Find Full Text PDF

We report the first implementation of ion mobility mass spectrometry combined with an ultra-high throughput sample introduction technology for high throughput screening (HTS). The system integrates differential ion mobility (DMS) with acoustic ejection mass spectrometry (AEMS), termed DAEMS, enabling the simultaneous quantitation of structural isomers that are the sub-strates and products of isomerase mediated reactions in intermediary metabolism. We demonstrate this potential by comparing DAEMS to a luminescence assay for the isoform of phosphoglycerate mutase (iPGM) distinctively present in pathogens offering an opportunity as a drug target for a variety of microbial and parasite borne diseases.

View Article and Find Full Text PDF

Wide field retinal imaging has emerged as a transformative technology over the last few decades, revolutionizing our ability to visualize the intricate landscape of the retina. By capturing expansive retinal areas, these techniques offer a panoramic view going beyond traditional imaging methods. In this review, we explore the significance of retinal imaging-based biomarkers to help diagnose ocular and systemic conditions.

View Article and Find Full Text PDF

Objective: [F]FDG imaging is an integral part of patient management in CAR-T-cell therapy for recurrent or therapy-refractory DLBCL. The calculation methods of predictive power of specific imaging parameters still remains elusive. With this retrospective study, we sought to evaluate the predictive power of the baseline metabolic parameters and tumor burden calculated with automated segmentation via different thresholding methods for early therapy failure and mortality risk in DLBCL patients.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!