In recent years, there has been a dramatic increase in the use of improvised explosive devices (IEDs) due to ease of synthesis and improved controls placed on commercial/military explosives. Commonly used materials for IED preparations include fertilizers and industrial chemicals containing oxidizers such as ClO3-, ClO4-, and NO3-, as well as other less stable compounds, such as peroxides. Due to these materials having a wide range of volatility, polarity, and composition, detection can be challenging, increasing the amount of time before any analytical information on the identity of the explosive can be determined. Therefore, this research project developed two analytical methods to aid in the rapid detection of multiple explosive compounds. The use of microfluidic paper-based analytical devices (µPADs) allows for the development of inexpensive paper devices utilizing colorimetric reactions, which can perform five or more simultaneous analyses in approximately five minutes. Two devices were developed: one for the detection of inorganic explosives including ClO3-, ClO4-, NH4+, NO3-, and NO2-, and the second device detects high/organic explosives including RDX, TNT, urea nitrate, and peroxides. Limits of detection ranged from 0.4 µg – 20 µg of explosive residue with an analysis time of less than five minutes. Development of a confirmatory method utilizing infusion electrochemical detection-electrospray ionization-time-of-flight mass spectrometry (EC-ESI-TOF MS) and 18-crown-6 ethers to produce guest/host complexes with inorganic ions has also been completed. Utilizing this method the inorganic ions present in many IEDs can be successfully detected as ion pairs, while still allowing for the detection of other high explosives1. Placing an electrochemical detector before the mass spectrometer permits the detection of hydrogen peroxide, an analyte normally difficult to detect through mass spectrometry. Limits of detection ranged from 0.06 ppm - 2 ppm with an analysis time of less than two minutes. The development of these presumptive and confirmatory analytical methods permits the detection of a wide range of components present in IEDs. These methods decrease the amount of time required to relay information on the type of explosives present by simplifying the analysis process in the field and in a laboratory.

The oxidative folding pathway of the disulfide containing protein bovine pancreatic trypsin inhibitor (BPTI) was one of the first to be elucidated and has served as a basis for understanding the folding pathways of other proteins. During the oxidative folding of reduced BPTI, two intermediates (N' and N*) accumulate in significant amounts and act as kinetic traps. Both N' and N* bury their two remaining free thiols in their hydrophobic cores, which inhibits further oxidation. Historically, the rate limiting step was considered to be the intramolecular rearrangements of N' and N* to another intermediate with two free thiols, NSH. The two free thiols in NSH are solvent-exposed and easily oxidized to a disulfide, producing native protein (N). Nevertheless, our research using reduced BPTI indicated that the folding rate of N* to N was proportional to the concentration of added glutathione disulfide (GSSG), inconsistent with the slow intramolecular rearrangement of N* to NSH. To confirm our initial results, the intermediate N* was purified and refolded in the presence of GSSG. The conversion of N* to N was dependent upon the disulfide concentration and singly mixed disulfide N*(SG) was observed during folding. These results emphasize that the folding of N* can proceed via a growth type pathway, direct oxidation of the two remaining thiols in N* by an exogenous small molecule disulfide, such as GSSG, to form N. Folding of reduced BPTI via N* was performed under changing concentrations of GSSG and GSH as a function of time. The folding was improved dramatically in terms of rate and yield. Aromatic disulfides and thiols have been demonstrated to improve the folding efficiency of disulfide containing proteins including ribonuclease A (RNase A) and lysozyme. Herein, N* and N' were refolded in the presence of aromatic disulfides. Folding of the two kinetic traps with aromatic disulfides indicated that folding proceed via a growth type pathway. The singly and doubly mixed disulfide intermediates were observed during most folding reactions. The oxidative folding of reduced BPTI with aromatic disulfides and thiols were also investigated. Reduced BPTI can be folded to disulfide intermediates rapidly.

Novel psychoactive substances (NPS) represent a great challenge to toxicologists due to the ability of illicit drug manufacturers to alter NPS chemical structures quickly and with ease to circumvent legislation regulating their use. Each time a new structure is introduced, there is a possibility that it has not been previously recorded in law enforcement or scientific databases. Many toxicology laboratories use targeted analytical methods that rely on libraries of known compounds to identify drugs in samples. However, these libraries do not include large numbers of NPS which could result in non-identification or detection. High-resolution mass spectrometry (HRMS) has been suggested as a method for screening a wide variety of analytes due to its higher sensitivity and mass accuracy as compared to some other forms of mass spectrometry. This technique can generate characteristic MS/MS spectral data for use in compound identification. The main goal of this research was to create a high-resolution mass spectrometry (HRMS) library of NPS and metabolites, as well as validate a method for screening and confirmation of these substances. The study consisted of three main tasks which included; the development of a large high-resolution MS/MS spectral library and database, validation of a method for screening and confirmation of over 800 NPS and metabolites, and screening of blind-spiked and authentic urine specimens to determine real-world applicability of the HRMS library and method. During validation, several isomeric and structurally related NPS were observed which could not be adequately separated using traditional LC methods. A fourth task was therefore added to investigate improved separation using two-dimensional liquid chromatography (2D-LC). Increased resolving power is achieved in 2D-LC through the coupling of multiple orthogonal separation systems. Ultimately, an on-line, comprehensive method was developed using orthogonal reversed-phase columns in each dimension (RP x RP) for improved separation of co-eluting and isomeric synthetic cannabinoids. This work can aid laboratories in the identification of NPS through the use of a validated LC-QTOF-MS method for screening and confirmation and HRMS spectral library. In instances where isomeric and structurally related NPS are not sufficiently separated, RP x RP methods can be explored.

In this work, a comparative electrochemical study has been performed to evaluate corrosion inhibition property of several film-forming corrosion inhibitors provide by Akzo Nobel on carbon steel in a chloride solution. For carbon steel exposed to 1 M NaCl solution with and without added inhibitor, electrochemical measurements including electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) at different exposure time intervals, and potentiodynamic polarization at the termination of the exposure, have been performed to investigate the film forming process and to evaluate corrosion inhibition efficiency of the inhibitors, as well as its evolution with time. The corrosion resistance data obtained from the EIS and LPR measurements are in good agreement. The results indicate different inhibition properties of the inhibitors tested. The inhibition effect of SSF CI-1 is negligible in the first hour of exposure, but it increases steadily with time for 1 day, and then remains the same level during the exposure up to one week. SSF CI-2 exhibits a good inhibition effect in the first hour, but the effect decreases with time to a low level after 8 hours, and then increases again with prolonged exposure. SSF CI-4 shows a low inhibition effect during the first day, and then increases to a maximum level after three days’ exposure. For SSF CI-5 and SSF CI-6, the inhibition effect within 8 hours is relative low but higher than that of SSF CI-4, and the effect increases with time during prolonged exposure. The SSF CI-5 seems to be better than SSF CI-6 because of a more stable inhibition effect. The EIS results indicate that most of the inhibitors form a resistive surface film on carbon steel, which becomes more resistive and protective after several days’ of exposure. However, in the initial stage of exposure, the SSF CI-6 does not show an effect of formation of a resistive film on the surface. The potentiodynamic polarization measurements suggest that, SSF CI-1 and SSF CI-2 are anodic type inhibitor, SSF CI-4 is cathodic type inhibitor, and SSF CI-5 and SSF CI-6 are mix type inhibitor. Moreover, the inhibitors tested show a similar corrosion inhibition effect as mussel adhesive protein (MAP) at the low dosage level.

Numerous metal release data have been published by the Div. Surface and Corrosion Science and the AISI 316L stainless steel particles’ behavior in artificial lysosomal fluid (ALF). This study aims to evaluate the effect of chemical components in ALF on metal release from stainless steel particles with a bottom-up methodology. Two sizes of 316L stainless steel particles were used to assess the particle size influence on the metal release in detail. The results show that organic complexing agents e.g. lactate, tartrate and citrate are responsible for the high metal release rate in ALF. Correlations between the metal release rate and the number of carboxyl groups of the organic ligand were observed. Moreover, metal release data in this study indicates no synergistic effects in ALF solution, and continued research is on-going to study the synergistic effects further. No quantitative rules of iron, chromium and nickel release from the same stainless particles could be found which may indicate that these metals are released through different pathways e.g. diffusion or chemical dissolution. In different solutions with different chemical components, one or more metal release mechanisms dominate over others and make the metal release rate unpredictable.

The Swedish concept for storage of highly radioactive spent nuclear fuel is called the KBS-3 program. The proposed procedure is that the waste will be stored in a deep repository, 500 meters down in the Swedish bedrock, for 100 000 years. The fuel will be sealed inside cast iron cylinders surrounded by copper. The iron-copper canisters will then be placed one by one in holes and embedded in bentonite clay. The environment in the deep repository will be that of an underground rock cave, there will be groundwater and low amounts of oxygen present. Substances which are likely to react with the copper canister and cause corrosion are oxygen, sulphides and reactive water radiolysis products. Gamma radiation from the spent nuclear fuel will penetrate through the canister and further into the bentonite clay. When the gamma radiation comes in contact with the water in the bentonite clay, water radiolysis will occur. Corrosive radiolysis products are for example hydroxyl radicals, solvated electrons and hydrogen peroxide. The main purpose of this work was to study the effect of gamma radiation on copper pieces, in an aqueous environment, both under oxic and anoxic conditions. The surfaces of the copper pieces were characterized using scanning electron microscopy (SEM) and infrared absorption spectroscopy (IRAS). The dissolution of copper was measured using inductively coupled plasma spectroscopy (ICP). A second study was also performed where the reactions of three different oxidants; hydrogen peroxide, permanganate and iridium hexachloride, were studied in the presence of copper in an inert environment. All of the reactions were studied spectrophotometrically and the dissolution of copper was measured using inductively coupled plasma spectroscopy (ICP). The SEM measurements showed corrosion products on the irradiated copper pieces both under oxic and anoxic conditions. Under anoxic conditions the corrosion products had a center of a small cavity which was surrounded by a larger, flat, circular area. From that area, wider cavities were spreading out in apparently random directions. SEM-EDS measurements detected oxygen on the surface of the corrosion products. ICP measurements of the water phase showed that the water from irradiated samples contained higher levels of copper than unirradiated samples. ICP measurements from the reactions of copper in the presence of oxidants showed that copper was only dissolved in the presence of iridium hexachloride. These results show that gamma radiation causes corrosion of copper in an aqueous environment, both under oxic and anoxic conditions. It can also be concluded that hydrogen peroxide is not the radiolysis product that causes the dissolution of copper when copper is irradiated in an aqueous and inert environment.

Syftet med denna studie är att undersöka utifrån ett lärarperspektiv vilken roll kemiläraren har för att stärka elevers motivation,samt belysa hur läraren bedriver undervisning i ämnet som hjälper eleverna att bli motiverade i kemiämnet. Undersökningen genomfördes  med fem kemilärare på högstadiet i två grundskolor i södra Sverige. Denna studie bygger på den kvalitativa metoden där semistrukturerade intervjuer har använts som redskap för att samla in impirin.

The conversion of ammonia nitrogen to nitrite and nitrate forms of nitrogen has aroused much attention in the past and continues to receive much of the energy of the present day researcher. It has been known for many years that the phenomenon of nitrification is almost in its entirety a biological process. In 1862, Louis Pasteur demonstrated the microbiological nature of the oxidation of alcohol to acetic acid. He suggested that the oxidation of ammonia might be of similar nature. In 1877 this suggestion was verified by schloesing and Muntz, and for the next ten years the process received much attention, culminating in 1891 in the isolation of the responsible organisms by Winogradsky.

The test production of a simulated nuclear fuel, possible to use as a calibration standard was donethru dissolving the preferred dopant-metals in a nitric-salt into weak acid. This solution wasmixed with dissolved uranium-salt to aimed concentration. This was precipitated by rising pHforming metallic-hydroxide.The precipitated salt was dried in an reduction gas, pressed to pellets and sintered in oven. Thequality of the pellets and its content was evaluated thru comparing theoretical and measureddensity, ICP-MS for which ground elements and which concentration of these forming thepellets. XRD was used to evaluate formed associated ground-elements and the lattice parameters.Finally, SEM was used to evaluate how homogenous the distribution of the doped elementsturned out.There are still a variety of tests yet to perform in order to create a high quality calibrationstandard. Our preparation of dissolved metallic salts will hopefully be usable for any furtherexperimentalist in this field. The single-doped calibration-standards are aimed to be used byStudsvik to calibrate their Lazer Ablation Inductivity coupled Plasma Mass Spectrometryinstrument.

Water is an essential and indispensable component is the pulp- and paper production industry.The increase in energy costs, stricter environmental regulations and water resource shortageshave caused a reduction of the water footprint in the industry as well as an increase in waterrecycling and water circuit closure. Reducing water usage requires an understanding of wherecontaminants originate, as well as which streams are critical to the process and how they impactmill operation. The recirculation of water can cause contaminant accumulation; therefore millsemploy technologies for water treatment in the internal water cycles, the so-called ‘kidneys’.Application of membrane technology is one such option which can improve the recycled waterquality and reduce contaminant buildup.The present study was carried out on a lab-scale for the treatment of a tissue mill effluent usingmembrane separation. A combination of pretreatment methods and various membranes werecompared with regards to separation, flux and fouling. The AlfaLaval M20 device was to treatwastewater samples sent from the mill, where the permeate was recirculated to the feed tank.COD and TOC levels are compared with regards to determining the separation efficiency. Thepermeate flux was measured over the two-hour filtration period, as well as flux recovery todetermine fouling levels. Additionally, some economic aspects of the process are discussed.This study suggests the potential application of a combination of flocculation or centrifugationpretreatment, with reverse osmosis membranes for recycling water to replace freshwater intake.The results also indicate the possibility of using ultrafiltration as kidneys to decreasecontamination buildup for further water loop closure.