Browsing by Author "Dutkiewicz, Ewelina P."

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Blotting paper as a disposable tool for sampling chemical residues from skin surface
(2019-04-01)
Wu, Pei-Chi
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Dutkiewicz, Ewelina P.
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Liao, Pei-Han
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Chiu, Hsien-Yi
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Urban, Pawel L.
Cool Mist Scavenging of Gas-Phase Molecules
(2017-10-01)
Wu, Pei-Chi
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Dutkiewicz, Ewelina P.
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Urban, Pawel L.
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應用化學系
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Department of Applied Chemistry
The purpose of analytical extractions is to simplify sample matrix without losing analyte molecules. Here we present a technique of extracting volatile compounds by scavenging gas-phase molecules with tiny liquid droplets (<10 mu m). A cool mist of the extracting solvent is generated by an ultrasonic transducer, transferred to the headspace of the sample chamber under atmospheric conditions, and pushed by a small pressure difference toward a condenser. By slowly passing over the sample, the microdroplets extract volatile species present in the sample headspace, and they coalesce in a cooled zone. The condensed liquid is collected for analysis by direct infusion mass spectrometry or chromatography coupled with mass spectrometry. Due to the high surface-to-volume ratio of the microdroplets, the mist depletes a great share of the volatile organics present in the headspace. Other advantages of cool mist scavenging include: selective extraction of gas-phase molecules, the extracting solvent can be miscible with the sample solvent, simplicity, high speed, and no requirement for heating that could potentially decompose the sample. In this study, cool mist scavenging was first tested on artificial samples containing esters. The relationship between the sample concentration and the extract concentration was verified theoretically and experimentally. Some of the possible confounding effects were tested and discussed. The technique was subsequently applied to qualitative analysis of selected complex samples in liquid and solid phase as well as an esterification reaction.
Hydrogel Micropatch and Mass Spectrometry-Assisted Screening for Psoriasis-Related Skin Metabolites
(2016-08)
Dutkiewicz, Ewelina P.
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Hsieh, Kai-Ta
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Wang, Yi-Sheng
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Chiu, Hsien-Yi
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Urban, Pawel L.
BACKGROUND: Psoriasis is a chronic, immune-mediated inflammatory skin disease. Screening skin metabolites could unravel the pathophysiology of psoriasis and provide new diagnostic approaches. Due to the lack of suitable methodologies for collecting scarce amounts of skin excretions, the psoriatic skin metabolome has not been extensively studied. METHODS: We implemented biocompatible hydrogel micropatch probes combined with mass spectrometry to investigate the skin metabolome. This noninvasive approach was applied to examine samples obtained from 100 psoriatic patients and 100 healthy individuals. We also developed custom data treatment tools and used chemometric and statistical tools to reveal the alterations in the skin metabolome caused by psoriasis. RESULTS: The proposed methodology enabled us to capture alterations in the composition of skin excretions caused by the disease. Chemometric analysis revealed the major differences between the metabolomes of psoriatic skin and healthy skin. Several polar metabolites were positively (choline and glutamic acid) or negatively ( urocanic acid and citrulline) correlated with the plaque severity scores. The amounts of these metabolites in the excretions sampled from psoriatic skin were significantly different (P < 0.001) from the excretions sampled from healthy skin. The role of biological variability and various confounding factors, which might affect the skin metabolome, was also investigated. CONCLUSIONS: Sampling lesional and healthy skin with the hydrogel micropatch probes and subsequent direct mass spectrometry scanning provided information on the alterations in the skin metabolome caused by psoriasis, increasing the understanding of the complex pathophysiology of this disease. (C) 2016 American Association for Clinical Chemistry
Hydrogel Micropatches for Sampling and Profiling Skin Metabolites
(2014-03-04)
Dutkiewicz, Ewelina P.
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Lin, Jia-Der
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Tseng, Te-Wei
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Wang, Yi-Sheng
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Urban, Pawel L.
Metabolites excreted by skin have a huge potential as disease biomarkers. However, due to the shortage of convenient sampling/analysis methods, the analysis of sweat has not become very popular in the clinical setting (pilocarpine iontophoresis being a prominent exception). In this report, a facile method for sampling and rapid chemical profiling of skin metabolites excreted with sweat is proposed. Metabolites released by skin (primarily the constituents of sweat) are collected into hydrogel (agarose) micropatches. Subsequently, they are extracted in an online analytical setup incorporating nanospray desorption electrospray ionization and an ion trap mass spectrometer. In a series of reference measurements, using bulk sampling and electrospray ionization mass spectrometry, various low-molecular-weight metabolites are detected in the micropatches exposed to skin. The sampling time is as short as 10 min, while the desorption time is 2 min. Technical precision of micropatch analysis varies within the range of 3-42%, depending on the sample and the method of data treatment; the best technical precision (<= 10%) has been achieved while using an isotopically labeled internal standard. The limits of detection range from 7 to 278 pmol. Differences in the quantities of extracted metabolites are observed for the samples obtained from healthy individuals (intersubject variabilities: 30-89%; n = 9), which suggests that this method may have the potential to become a semiquantitative assay in clinical analysis and forensics.
Kinetic study of continuous liquid-liquid extraction of wine with real-time detection
(2018-11-30)
Yang, Hui-Hsien
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Dutkiewicz, Ewelina P.
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Urban, Pawel L.
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應用化學系
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Department of Applied Chemistry
Kinetic optimization of continuous liquid-liquid extraction (CLLE) can shorten sample preparation times and reduce losses of labile or volatile analytes. Here, we coupled a downscaled CLLE apparatus with atmospheric pressure chemical ionization interface of triple quadrupole mass spectrometer. Real-time sampling was guided by an Arduino-based programmable logic controller. The recorded datasets were processed to compute the extraction rate constants for the target analytes. The extraction time in subsequent on-line experiments was set to 180 min as a compromise between the reduction of the analysis time and maximizing its yield. Interestingly, off-line analysis of the extract produced different results than on-line analysis pointing to the immanent degradation of the collected extract aliquots. Next, we implemented this hyphenated system in the analysis of red wine samples, which were stored during different periods of time after opening the bottle. The results reveal differences in the depletion of the volatile wine components during storage. (C) 2018 Elsevier B.V. All rights reserved.
Micropatch-arrayed pads for non-invasive spatial and temporal profiling of topical drugs on skin surface
(2015-11-01)
Dutkiewicz, Ewelina P.
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Chiu, Hsien-Yi
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Urban, Pawel L.
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應用化學系
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應用化學系分子科學碩博班
Micropatch-arrayed pads (MAPAs) are presented as a facile and sensitive sampling method for spatial profiling of topical agents adsorbed on the surface of skin. MAPAs are 28 x 28 mm sized pieces of polytetrafluoroethylene containing plurality of cavities filled with agarose hydrogel. They are affixed onto skin for 10 min with the purpose to collect drugs applied topically. Polar compounds are absorbed by the hydrogel micropatches. The probes are subsequently scanned by an automated nanospray desorption electrospray ionization mass spectrometry system operated in the tapping dual-polarity mode. When the liquid junction gets into contact with every micropatch, polar compounds absorbed in the hydrogel matrix are desorbed and transferred to the ion source. A 3D-printed interface prevents evaporation of hydrogel micropatches assuring good reproducibility and sensitivity. MAPAs have been applied to follow dispersion of topical drugs applied to human skin in vivo and to porcine skin ex vivo, in the form of self-adhesive patches. Spatiotemporal characteristics of the drug dispersion process have been revealed using this non-invasive test. Differences between drug dispersion in vivo and ex vivo could be observed. We envision that MAPAs can be used to investigate spatiotemporal kinetics of various topical agents utilized in medical treatment. Copyright (c) 2015 John Wiley & Sons, Ltd.
Probing Skin for Metabolites and Topical Drugs with Hydrogel Micropatches
(2017-03-07)
Dutkiewicz, Ewelina P.
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Chiu, Hsien-Yi
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Urban, Pawel L.
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應用化學系
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應用化學系分子科學碩博班
Sampling the skin surface is a convenient way to obtain biological specimens bearing clinically relevant information. Hydrogel micropatches enable noninvasive collection of skin excretion specimens, which can subsequently be subjected to rapid mass spectrometric analysis providing insights into the skin metabolome.
Quantitative mass spectrometry of unconventional human biological matrices
(2016-10-28)
Dutkiewicz, Ewelina P.
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Urban, Pawel L.
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應用化學系
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應用化學系分子科學碩博班
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Department of Applied Chemistry
The development of sensitive and versatile mass spectrometric methodology has fuelled interest in the analysis of metabolites and drugs in unconventional biological specimens. Here, we discuss the analysis of eight human matrices-hair, nail, breath, saliva, tears, meibum, nasal mucus and skin excretions (including sweat)-by mass spectrometry (MS). The use of such specimens brings a number of advantages, the most important being non-invasive sampling, the limited risk of adulteration and the ability to obtain information that complements blood and urine tests. The most often studied matrices are hair, breath and saliva. This review primarily focuses on endogenous (e.g. potential biomarkers, hormones) and exogenous (e.g. drugs, environmental contaminants) small molecules. The majority of analytical methods used chromatographic separation prior to MS; however, such a hyphenated methodology greatly limits analytical throughput. On the other hand, the mass spectrometric methods that exclude chromatographic separation are fast but suffer from matrix interferences. To enable development of quantitative assays for unconventional matrices, it is desirable to standardize the protocols for the analysis of each specimen and create appropriate certified reference materials. Overcoming these challenges will make analysis of unconventional human biological matrices more common in a clinical setting. This article is part of the themed issue \'Quantitative mass spectrometry\'.