Ion mobility based separation techniques for the direct analysis of gaseous and solid samples and fundamental studies of gas phase reactions

This thesis describes the applicability of different types of IMS instruments in the direct measurements of gaseous and solid samples and in fundamental studies of gas-phase ion chemistry. A handheld chemical detector containing an aspiration ion mobility spectrometry (AIMS) was applied in the monitoring of gas phase explosive triacetone triperoxide (TATP) from air flow. The instrument-normalized detection threshold (20 pA) was exceeded already with the lowest sample concentration of 0.3 mg m−3. The response time of the instrument was less than five seconds. AIMS was also used to monitor chemical changes in the headspaces of the chambers containing microbe contaminated and sterile particle board samples in humid conditions. It was possible to separate the distinct chemical profiles of the chambers with sterile and microbe-contaminated specimen by principal component analysis. Overall, AIMS was found to be an adequate technique in dynamic screening of TATP and in monitoring of the changes in the microbe metabolism. Ambient ionization techniques, direct analysis in real time (DART) and desorption atmospheric pressure photoionization (DAPPI), were combined with travelling wave ion mobility-mass spectrometry. In the surface analysis of almond, pharmaceuticals, vitamin tablets and dried blood spot sample, the ion mobility separation reduced the chemical noise in the mass spectra and increased the signal-to-noise ratio. In the comparative studies of DAPPI and DART ionization, the limits of detection were between 30−290 and 330−8200 fmol for DAPPI and DART, respectively, for the tested compounds bisphenol A, benzo[a]pyrene, ranitidine, cortisol, and α-tocopherol. Finally, the reactions of phenol and fluorinated phenols with Cl− in ambient pressure were investigated by drift tube ion mobility-mass spectrometry. For the least fluorinated phenols (phenol, 2-fluorophenol and 2,4-difluorophenol) with the lowest gas-phase acidities, the Cl− adducts [M+Cl]− and [2M+Cl]− were the major products in both low and high sample concentration. For the highly fluorinated phenols (2,3,6-trifluorophenol and pentafluorophenol), [M−H]− and [2M−H]− were the main products in high sample concentration. In low concentration [M−H]− and [M+Cl]− were the main products. In case of pentafluorophenol (PFP), in high temperature conditions the dimer was [2PFP−H]− instead of [2PFP+Cl]−. In conclusion, IMS has many advantages and application possibilities. It allows the rapid detection and continuous monitoring of volatiles directly from ambient air. IMS can also be used as a pre-separation technique in ambient mass spectrometry, without increasing the total analysis time remarkably. In IMS, it is also possible to study gas phase reactions in ambient conditions. Some of the IMS applications presented in this thesis could be developed further to be a permanent part of routine monitoring, analysis, and research work. For example, in the fundamental studies of phenols, the possibility to use updated versions of the instruments could improve the accuracy of the experiments. In addition, broader studies with several experimental conditions, would increase the possibility to develop the method further, especially in the monitoring of TATP, and building material and microbe emissions from the gas phase with AIMS.Ioniliikkuvuusspektrometrisissa (IMS) menetelmissä kaasufaasissa olevat ionit erotellaan sähkökentän avulla ennen detektointia. Ionien erottumiseen vaikuttavat ionien massa, varaus ja koko. Tämä väitöskirja kuvaa erityyppisten IMS-menetelmien soveltuvuutta tutkittavien yhdisteiden suoraan analysointiin kaasumaisista ja kiinteistä näytteistä sekä kaasufaasi-ionikemian perustutkimukseen. Kannettavaa aspiraatio-ioniliikkuvuusspektrometrin (AIMS) sisältävää kaasudetektoria käytettiin kaasumaisen räjähteen triasetoni triperoksidin (TATP) monitorointiin ilmavirrasta. AIMS:n normalisoitu toteamisraja (20 pA) ylitettiin jo alhaisimmalla näytepitoisuudella 0.3 mg m-3 (0.03 ppm). Laitteen vasteaika oli alle viisi sekuntia. A-IMS:a käytettiin myös mittaamaan mikrobien haihtuvien aineenvaihduntatuotteiden ja rakennusmateriaalin emissiotuotteiden pitoisuuksien muutoksia steriilejä ja mikrobien kontaminoimia lastulevykappaleita sisältävien kammioiden kosteasta ilmatilasta. Kammioiden ilmatilojen kemialliset profiilit oli mahdollista erotella käyttämällä pääkomponenttianalyysiä. Suorat pintaionisaatiotekniikat desorptioilmanpainefotoionisaatio (DAPPI) ja suora reaaliaikainen analyysi (DART) yhdistettiin ioniliikkuvuus-massaspektrometri menetelmän travelling wave ion mobility-mass spectrometry (TWIM-MS) kanssa. Analysoitaessa mantelin, lääkkeiden, vitamiinitablettien ja kuivattujen veripisaranäytteiden pintaa, ioniliikkuvuuserotus ennen massaspektrometristä analyysiä vähensi kemiallista kohinaa massaspektrissä ja kasvatti signaali-kohinasuhdetta. DAPPI:n ja DART:n vertailevassa tutkimuksessa, DAPPI:n toteamisrajat olivat 30-290 fmol ja DART:n 330-8200 fmol. Tutkittavat yhdisteet olivat bisfenoli A, bentso[a]pyreeni, kortisoli, ranitidiini ja α-tokoferoli. Lopuksi, lentoaika-ioniliikkuvuus-massaspektrometriä käytettiin fenolin ja fluorattujen fenolien, ja Cl−-ionin reaktiotuotteiden tutkimiseen normaalissa ilmanpaineessa. Tutkimuksessa havaittiin, että yhdisteiden happamuus vaikutti reaktiotuotteiden muodostumiseen. Lievästi happamat yhdisteet muodostivat Cl−-addukteja sekä korkeassa että matalassa näytepitoisuudessa. Erittäin happamat yhdisteet reagoivat sekä protoninsiirtoreaktiolla että muodostivat Cl−-addukteja alhaisessa näytepitoisuudessa. Korkeassa näytepitoisuudessa happamilla yhdisteillä havaittiin pääasiassa protoninsiirtoreaktiolla muodostuneita reaktiotuotteita. Yhteenvetona, IMS mahdollistaa haihtuvien yhdisteiden nopean ja jatkuvan monitoroinnin suoraan ympäröivästä ilmasta ja IMS:a voidaan käyttää esierotusmenetelmänä suorien pintaionisaatiotekniikoiden yhteydessä, ilman että analyysiaika merkittävästi kasvaa. Lisäksi, IMS:lla voidaan tutkia kaasufaasissa tapahtuvia reaktioita normaalissa ilmanpaineessa. Tässä tutkimuksessa esitettyjä IMS-sovelluksia voitaisiin käyttää rutiinianalytiikassa ja tutkimustyössä, mutta tämän toteutuminen vaatisi laajoja lisätutkimuksia

Chemical profiles of birch and alder bark by ambient mass spectrometry

Desorption atmospheric pressure photoionization (DAPPI) is an ambient mass spectrometry (MS) technique that allows the analysis of both polar and nonpolar compounds directly from the surfaces of various sample types. Here, DAPPI was used to study the chemical profiles in different parts of birch and alder tree barks. Four distinct fractions of Betula pendula (silver birch) bark were collected from three different developmental stages of the stem, after which the chemical profiles of the different tissue types were measured. Of special interest were triterpenoids, a class of important defensive substances, which are found in the bark of the silver birch. Additionally, the chemical profiles of lenticels and the surrounding surfaces in the phellem of B. pendula (silver birch), Alnus glutinosa (black alder), and Alnus incana (gray alder) were screened with DAPPI. Another ambient MS technique, laser ablation atmospheric pressure photoionization (LAAPPI), was further used for the mass spectrometry imaging of lenticels on the B. pendula phellem. All the studied birch bark fractions showed individual chemical profiles in DAPPI. The mass spectra from the young apical stem and the transition zone resembled each other more than the mature stem. Instead, the phellem was found to contain a high amount of triterpenoids in all the developmental stages of the stem. The most intense peaks in the DAPPI mass spectra of the birch bark fractions were those of betulin and lupeol. Betulinic and betulonic acid peaks were intense as well, and these compounds were detected especially in the lenticels of the tree samples.Peer reviewe

Shopping Detail Information and Home Freezer Sampling Confirmed the Role of Commercial, Modified-Atmosphere Packaged Meatballs as a Vehicle for Listeriosis in Finland

In November 2016, an elderly patient was diagnosed with Listeria monocytogenes bacteremia in Finland. Grocery store loyalty card records and microbiological investigation of foods found in the home fridge and freezer of the patient revealed commercial, modified-atmosphere packaged meatballs as the source of the infection. Investigation of the meatball production plant revealed that the floor drain samples were contaminated with the same L. monocytogenes strain as those isolated from the patient and meatballs. Ready-to-eat meatballs were likely contaminated after heat treatment from the production environment before packaging. Long-term cold storage, modified-atmosphere conditions, and the absence of competing bacteria presumably enhanced the growth of L. monocytogenes. We recommend that collection of shopping details and home fridge and freezer sampling should be part of surveillance of all cases of L. monocytogenes infections to complement information obtained from in-depth interviews.Peer reviewe

Koti, hyvinvointityö ja haavoittuvuus

In this book [titled Home, welfare work and vulnerability] the authors take the reader on welfare workers’ home visits to clients in need of support in their living. Welfare workers refer to professionals in health and social care who in the book are represented among others by social workers, social care workers and nurses. The main concepts of the book are home, welfare work and vulnerability and these are contemplated from different angles. Welfare work entails encountering people who are in vulnerable situations in the midst of their everyday lives. They may need support in coping with their mental health, with physical illnesses, with the challenges of achieving sobriety and recovery or perhaps with the difficulties accompanying old age. On the one hand their ability to act is limited and weak but on the other they have many kinds of strengths and resources. The book addresses a significant turning point in welfare services and work at which the objective is defined as the right of every individual to their own home and making living at home feasible for as long as possible. In the last fifty years or so many societal factors have made possible the dismantling of institutions, the reduction of places and the shortening of stays in institutions, the further development of care in the community, the construction of small residential and care facilities and most recently the further development of services to be taken into people’s homes. The last stage of this dismantling of institutions is referred to in the book as the “home turn”. As a societal change the home turn is complex – and that is how it is approached in the book. When one’s own home is the main place in which welfare policy and work are implemented, it is important to scrutinize more closely what actually occurs there and what special issues are connected to this given context. The book offers a timely point of view on the development of welfare services and the grass-root level welfare work done in the homes. It draws on interaction research based on ethnomethodology and human geography. Research data consist of recordings of home visits, researcher’s field diaries and interviews with clients and workers. The work includes both chapters providing conceptual and theoretical overviews and empirical research on the encounters between client and worker(s) on home visits. Welfare work accomplished in people’s homes entails many tensions and ethical issues which are analysed in the book and made visible through the means of research

Koti, hyvinvointityö ja haavoittuvuus

In this book [titled Home, welfare work and vulnerability] the authors take the reader on welfare workers’ home visits to clients in need of support in their living. Welfare workers refer to professionals in health and social care who in the book are represented among others by social workers, social care workers and nurses. The main concepts of the book are home, welfare work and vulnerability and these are contemplated from different angles. Welfare work entails encountering people who are in vulnerable situations in the midst of their everyday lives. They may need support in coping with their mental health, with physical illnesses, with the challenges of achieving sobriety and recovery or perhaps with the difficulties accompanying old age. On the one hand their ability to act is limited and weak but on the other they have many kinds of strengths and resources. The book addresses a significant turning point in welfare services and work at which the objective is defined as the right of every individual to their own home and making living at home feasible for as long as possible. In the last fifty years or so many societal factors have made possible the dismantling of institutions, the reduction of places and the shortening of stays in institutions, the further development of care in the community, the construction of small residential and care facilities and most recently the further development of services to be taken into people’s homes. The last stage of this dismantling of institutions is referred to in the book as the “home turn”. As a societal change the home turn is complex – and that is how it is approached in the book. When one’s own home is the main place in which welfare policy and work are implemented, it is important to scrutinize more closely what actually occurs there and what special issues are connected to this given context. The book offers a timely point of view on the development of welfare services and the grass-root level welfare work done in the homes. It draws on interaction research based on ethnomethodology and human geography. Research data consist of recordings of home visits, researcher’s field diaries and interviews with clients and workers. The work includes both chapters providing conceptual and theoretical overviews and empirical research on the encounters between client and worker(s) on home visits. Welfare work accomplished in people’s homes entails many tensions and ethical issues which are analysed in the book and made visible through the means of research

Tissue-specific study across the stem reveals the chemistry and transcriptome dynamics of birch bark.

Tree bark is a highly specialized array of tissues that plays important roles in plant protection and development. Bark tissues develop from two lateral meristems; the phellogen (cork cambium) produces the outermost stem-environment barrier called the periderm, while the vascular cambium contributes with phloem tissues. Although bark is diverse in terms of tissues, functions and species, it remains understudied at higher resolution. We dissected the stem of silver birch (Betula pendula) into eight major tissue types, and characterized these by a combined transcriptomics and metabolomics approach. We further analyzed the varying bark types within the Betulaceae family. The two meristems had a distinct contribution to the stem transcriptomic landscape. Furthermore, inter- and intraspecies analyses illustrated the unique molecular profile of the phellem. We identified multiple tissue-specific metabolic pathways, such as the mevalonate/betulin biosynthesis pathway, that displayed differential evolution within the Betulaceae. A detailed analysis of suberin and betulin biosynthesis pathways identified a set of underlying regulators and highlighted the important role of local, small-scale gene duplication events in the evolution of metabolic pathways. This work reveals the transcriptome and metabolic diversity among bark tissues and provides insights to its development and evolution, as well as its biotechnological applications.peerReviewe