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Start Over Topic ambient ionization Publication Year Range Last 50 years Language english
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1. In Situ Separation and Analysis of Lipids by Paper Spray Ionization Mass Spectrometry

Author

Sangwon Cha and Youngju Kal

Subjects
Paper, Spectrometry, Mass, Electrospray Ionization, Analyte, Electrospray, Base (chemistry), Analytical chemistry, Pharmaceutical Science, Mass spectrometry, 01 natural sciences, Analytical Chemistry, lipids, lcsh:QD241-441, lcsh:Organic chemistry, Ionization, Drug Discovery, Animals, Physical and Theoretical Chemistry, phosphatidylcholine, Triglycerides, Ambient ionization, mass spectrometry, chemistry.chemical_classification, Quantitative Biology::Biomolecules, Physics::Biological Physics, 010405 organic chemistry, Chemistry, Communication, 010401 analytical chemistry, Organic Chemistry, 0104 chemical sciences, Solvent, Condensed Matter::Soft Condensed Matter, Chemistry (miscellaneous), paper spray ionization, Phosphatidylcholines, Solvents, Molecular Medicine, Polar, triacylglycerol
Abstract

Paper spray ionization (PSI) is an extractive ambient ionization technique for mass spectrometry (MS), whereby a triangular paper tip serves as the sampling base and the electrospray tip. During PSI, analytes are extracted and transported to the edge of the paper tip by the applied spraying solvent. Analytes can be purified from a sample matrix and separated from each other by this transportation process. In this study, we investigated and utilized the analyte transportation process of PSI for the in situ separation and analysis of lipid mixtures. We found that differential transport of phosphatidylcholine (PC) and triacylglycerol (TAG), the two most abundant lipid classes in animals, occurred during PSI. We also found that the order in which these lipids moved strongly depended on how the spraying solvent was applied to the paper base. The more polar PC moved faster than the less polar TAG during PSI, when a polar solvent was slowly fed into a paper tip, whereas TAG was transported faster than PC when excess solvent was applied to the tip at once. In addition, we achieved a complete separation and detection of PC and TAG by slowly supplying a nonpolar solvent to a PSI tip.

Published
2021

2. Direct analysis in real time accurate mass spectrometry determination of bisphenol A in thermal printing paper.

Author

Castro, G., Rodríguez, I., Ramil, M., and Cela, R.

Subjects
*BISPHENOL A, *MASS spectrometry, *HELIUM atom, *TANDEM mass spectrometry, *PAPER
Abstract

Contact with thermal printing paper is a relevant source of dermal exposure to unbonded bisphenol A (BPA). In order to limit this exposure route, the European Union has introduced a drastic reduction in the maximum allowed concentration of BPA in thermal paper produced after beginning of year 2020. This study investigates the suitability of direct analysis in real time (DART), combined with accurate mass spectrometry, as a faster alternative to chromatography-based methods for the quantitative determination of BPA, and three analogues species, in receipts and tickets usually printed on thermal paper. The ionization efficiency of these compounds is evaluated under different conditions, and the effect of instrumental parameters of the DART source in the observed responses is discussed. The yield of the DART desorption-ionization process was greatly improved when compounds are previously converted into their acetyl derivatives; thereafter, the temperature of electronically excited helium atoms was the most relevant of the evaluated instrumental parameters. Under optimized conditions, the reported method provided recoveries in the range from 90 to 110%, a limit of quantification of 0.004% (w:w), well below the maximum concentration established after 2020 for BPA (0.02%, w:w), and permitted to perform duplicate determinations of each sample extract with a response time around 1 min. The accuracy of BPA levels found in non-spiked samples was confirmed using GC-EI-MS as reference technique. BPA was systematically noticed in the processed samples with concentrations ranging from 0.005% to more than 6%. Image 1 • Rapid determination of bisphenol A in thermal printing paper by DART accurate MS. • Acetylation greatly enhances the yield of DART desorption-ionization. • Procedural LOQs below limits set for bisphenol A in thermal paper. • Good correlation between DART-MS and GC-EI-MS values in thermal paper samples. [ABSTRACT FROM AUTHOR]

Published
2019
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3. Silica Coated Paper Substrate for Paper-Spray Analysis of Therapeutic Drugs in Dried Blood Spots

Author

Zheng Ouyang, Nicholas E. Manicke, Zhiping Zhang, Wei Xu, and R. Graham Cooks

Subjects
Paper, Coated paper, Blood Specimen Collection, Chromatography, Silicon dioxide, Substrate (chemistry), Mass spectrometry, Silicon Dioxide, Sensitivity and Specificity, Article, Mass Spectrometry, Analytical Chemistry, Solvent, chemistry.chemical_compound, chemistry, Pharmaceutical Preparations, Verapamil, Solvents, Humans, Drug Monitoring, Quantitative analysis (chemistry), Dichloromethane, Ambient ionization
Abstract

Paper spray is a newly developed ambient ionization method that has been applied for direct qualitative and quantitative analysis of biological samples. The properties of the paper substrate and spray solution have a significant impact on the release of chemical compounds from complex sample matrices, the diffusion of the analytes through the substrate, and the formation of ions for mass spectrometry analysis. In this study, a commercially available silica-coated paper was explored in an attempt to improve the analysis of therapeutic drugs in dried blood spots (DBS). The dichloromethane/isopropanol solvent has been identified as an optimal spray solvent for the analysis. The comparison was made with paper spray using chromatography paper as substrate with methanol/water as solvent for the analysis of verapamil, citalopram, amitriptyline, lidocaine, and sunitinib in dried blood spots. It has been demonstrated that the efficiency of recovery of the analytes was notably improved with the silica coated paper and the limit of quantitation (LOQ) for the drug analysis was 0.1 ng mL(-1) using a commercial triple quadrupole mass spectrometer. The use of silica paper substrate also resulted in a sensitivity improvement of 5-50-fold in comparison with chromatography papers, including the Whatman ET31 paper used for blood cards. Analysis using a hand-held miniature mass spectrometer Mini 11 gave LOQs of 10-20 ng mL(-1) for the tested drugs, which is sufficient to cover the therapeutic ranges of these drugs.

Published
2011