NFDI4DS | UHH-SEMS - Publication Details

Andreas Ipsen

ORCID: 0000-0002-2566-8811

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A5049226102

Research Areas

Methane Hydrates and Related Phenomena
Seismic Waves and Analysis
Geophysics and Gravity Measurements
Ionosphere and magnetosphere dynamics
Earthquake Detection and Analysis
Seismology and Earthquake Studies
Astrophysics and Cosmic Phenomena
Superconducting Materials and Applications
Solar and Space Plasma Dynamics
Mass Spectrometry Techniques and Applications
Analytical Chemistry and Chromatography
Metabolomics and Mass Spectrometry Studies
Pesticide Residue Analysis and Safety
Spectroscopy and Chemometric Analyses
Advanced Chemical Sensor Technologies
Atomic and Molecular Physics
Markov Chains and Monte Carlo Methods
Ion-surface interactions and analysis
Isotope Analysis in Ecology
Scientific Research and Discoveries
Advanced Database Systems and Queries
Bayesian Methods and Mixture Models

Swansea University
2014-2023

Pacific Northwest National Laboratory
2015-2017

Environmental Molecular Sciences Laboratory
2015

Richland College
2015

Imperial College London
2008-2012

Approximate Bayesian computation scheme for parameter inference and model selection in dynamical systems

OPENALEX - Publications

Tina Toni David Welch Natalja Strelkowa Andreas Ipsen Michael P. H. Stumpf

Approximate Bayesian computation (ABC) methods can be used to evaluate posterior distributions without having calculate likelihoods. In this paper, we discuss and apply an ABC method based on sequential Monte Carlo (SMC) estimate parameters of dynamical models. We show that SMC provides information about the inferability model sensitivity changes in parameters, tends perform better than other approaches. The algorithm is applied several well-known biological systems, for which their credible...

10.1098/rsif.2008.0172 article EN Journal of The Royal Society Interface 2008-07-09

Ion manipulations in structures for lossless ion manipulations (SLIM): computational evaluation of a 90° turn and a switch

OPENALEX - Publications

Sandilya Garimella Yehia Ibrahim Ian Webb Andreas Ipsen Tsung-Chi Chen and 4 more

The process of redirecting ions through 90° turns and 'tee' switches utilizing Structures for Lossless Ion Manipulations (SLIM) was evaluated at 4 Torr pressure using SIMION simulations theoretical methods. nature pseudo-potential in SLIM-tee structures has also been explored. Simulations show that 100% transmission efficiency SLIM devices can be achieved with guard electrode voltages lower than ∼10 V. ion plume width these conditions is ∼1.6 mm while lead to greater widths. Theoretical...

10.1039/c5an00844a article EN The Analyst 2015-01-01

A Statistically Rigorous Test for the Identification of Parent−Fragment Pairs in LC-MS Datasets

OPENALEX - Publications

Andreas Ipsen Elizabeth J. Want John C. Lindon Timothy M. D. Ebbels

Untargeted global metabolic profiling by liquid chromato-graphy−mass spectrometry generates numerous signals that are due to unknown compounds and whose identification forms an important challenge. The analysis of metabolite fragmentation patterns, following collision-induced dissociation, provides a valuable tool for identification, but can be severely impeded close chromatographic coelution distinct metabolites. We propose new algorithm identifying related parent−fragment pairs...

10.1021/ac902361f article EN publisher-specific-oa Analytical Chemistry 2010-02-09

Efficient Calculation of Exact Fine Structure Isotope Patterns via the Multidimensional Fourier Transform

OPENALEX - Publications

Andreas Ipsen

The isotope patterns of unknown analytes provide information that can be great value in their identification as part a mass spectrometry experiment. Determining the range compounds are consistent with an empirically observed pattern requires, initial step, calculation theoretical all feasible candidate formulas, and this is not trivial mathematical task. While algorithms based on Fourier transform have been used for almost two decades to perform such efficiently, they hitherto able exact...

10.1021/ac500108n article EN cc-by Analytical Chemistry 2014-05-19

Derivation of the Statistical Distribution of the Mass Peak Centroids of Mass Spectrometers Employing Analog-to-Digital Converters and Electron Multipliers

OPENALEX - Publications

Andreas Ipsen

The mass peak centroid is a quantity that at the core of spectrometry (MS). However, despite its central status in field, models statistical distribution are often chosen quite arbitrarily and without attempts establishing proper theoretical justification for their use. Recent work has demonstrated spectrometers employing analog-to-digital converters (ADCs) electron multipliers, intensity can be described via relatively simple model derived essentially from first principles. Building on this...

10.1021/acs.analchem.6b02446 article EN cc-by Analytical Chemistry 2017-02-03

Construction of Confidence Regions for Isotopic Abundance Patterns in LC/MS Data Sets for Rigorous Determination of Molecular Formulas

OPENALEX - Publications

Andreas Ipsen Elizabeth J. Want Timothy M. D. Ebbels

It has long been recognized that estimates of isotopic abundance patterns may be instrumental in identifying the many unknown compounds encountered when conducting untargeted metabolic profiling using liquid chromatography/mass spectrometry. While numerous methods have developed for assigning heuristic scores to rank degree fit observed with theoretical ones, little work done quantify errors are associated measurements made. Thus, it is generally not possible determine, a statistically...

10.1021/ac101278x article EN publisher-specific-oa Analytical Chemistry 2010-08-06

Prospects for a Statistical Theory of LC/TOFMS Data

OPENALEX - Publications

Andreas Ipsen Timothy M. D. Ebbels

The critical importance of employing sound statistical arguments when seeking to draw inferences from inexact measurements is well-established throughout the sciences. Yet fundamental methods such as hypothesis testing can currently be applied only a small subset data analytical problems encountered in LC/MS experiments. means inference that are more generally employed based on variety heuristic techniques and largely qualitative understanding their behavior. In this article, we attempt move...

10.1007/s13361-012-0340-z article EN cc-by Journal of the American Society for Mass Spectrometry 2012-02-28

Derivation from First Principles of the Statistical Distribution of the Mass Peak Intensities of MS Data

OPENALEX - Publications

Andreas Ipsen

Despite the widespread use of mass spectrometry (MS) in a broad range disciplines, nature MS data remains very poorly understood, and this places important constraints on quality analysis as well effectiveness instrument design. In following, procedure for calculating statistical distribution peak intensity instruments that analog-to-digital converters (ADCs) electron multipliers is presented. It demonstrated physical processes underlying data-generation process, from generation ions to...

10.1021/ac503554u article EN cc-by Analytical Chemistry 2015-01-24

Orders of Magnitude Extension of the Effective Dynamic Range of TDC-Based TOFMS Data Through Maximum Likelihood Estimation

OPENALEX - Publications

Andreas Ipsen Timothy M. D. Ebbels

In a recent article, we derived probability distribution that was shown to closely approximate of the data produced by liquid chromatography time-of-flight mass spectrometry (LC/TOFMS) instruments employing time-to-digital converters (TDCs) as part their detection system. The approach formulating detailed and highly accurate mathematical models LC/MS via distributions are parameterized quantities analytical interest does not appear have been fully explored before. However, believe it could...

10.1007/s13361-014-0961-5 article EN cc-by Journal of the American Society for Mass Spectrometry 2014-07-21

Data for EMSL Project 47418 from February 2023

OPENALEX - Publications