The so-called "lime-induced" chlorosis has been recognized for many years as a problem where plants are grown on calcareous soils. The characteristics associated with lime-induced chlorosis are the same as those associated with iron deficiency chlorosis--interveinal yellowing of the leaves at the meristemic region combined with reduced vigor of the plant as a whole. Lime-induced chlorosis is unique in that the iron content of both chlorotic plant and the soil do not always show a deficiency in iron when chemically analyzed. This leads to the theory that iron is inactivated in both the soil and plant. Although no single factor has been found to adequately explain this physiological disease, many factors have been associated with it. Thorne, Wann, and Robinson (1950) observed that calcareous soils characterized by fine texture, high moisture content, poor aeration, and cool temperatures intensify the development of chlorosis in plants. In general increased chlorosis has also been noted under conditions of high pH. The pH and phosphorus effects appear to involve reduced iron solubility in the soil and within the plant while the exact effects of the bicarbonate ion on chlorosis have not been established.

Soil-phosphorus relations have attracted the interest of many investigators since Liebig introduced his famous theory about the importance of the mineral matters to the plant in 1840. It was soon realized that phosphorus nutrition was a problem not easily solved for two reasons. 1. The added phosphorus fertilizers, soon after soil application are converted by some reactions in the soil to complex compounds far less soluble, consequently less available to the plant. Conclusions about this process led to controversial debates until it was discovered that a general statement covering all soils was impossible since the reactions involved in each case are different. 2. There was confusion caused by the use of two terms coined to express the plant's need for phosphorus. The first term, soluble phosphorus, was based on the assumption that nutrient absorption is a simple diffusion of ions from the soil solution into the roots while the second term, available phosphorus, was based on the observation that the plant absorbed more than that which could be estimated as soluble phosphorus from some insoluble sources. A general definition was given to the term available phosphorus as "that part of soil phosphorus which may be absorbed by ordinary crop plant in the production of plant substance." Later some restrictions were applied to regard the physical conditions of both soils and plants.

Syftet med undersökningen var att komma fram till hur man med hjälp av laborationer kan entusiasmera elever till att bli intresserade av kemi. Undersökningen utfördes i form av en enkät bland elever på gymnasiet (år 1-3). Enkäten hade en öppen struktur med dels öppna frågor men även frågor med flervalsalternativ. Elevsvaren har sammanställts i kategorier och diskuteras utifrån aktuell forskning. Resultatet visade att gymnasieeleverna efterfrågar laborationer med tydlig koppling till vardagen. De efterfrågar också en tydlig koppling mellan teori och laboration. Eleverna gav också uttryck för att det är viktigt med kunskaper i kemi för att påverka utvecklingen i framtiden samt kunna granska vad som skrivs och sägs i media. En slutsats av undersökningen är att man i elevgruppen finner elever med en inställning som tyder på att kemi anses som viktigt, men att man som lärare måste koppla laborationerna till såväl elevernas vardag som till teorin. Det innebär att en laboration om t.ex. syror och baser kan leda till att eleven lär sig såväl om försurning som om den mer teoretiska delen av kemin. För att sådana laborationer ska bli genomförbara krävs det noggrann förberedelse av läraren. Det är också viktigt i samband med laborationer att det förs diskussioner kring experimentets slutsats så att eleven med hjälp av t.ex. laborationen om syror och baser kan förklara försurning och hur det påverkar naturen, men även få stöd i sin teoretiska förståelse för syra-basreaktioner. På så sätt kan eleven använda sig av sin nyvunna kunskap från laborationen i ett större sammanhang.

Contaminated soils and sediments have been identified as significant secondary sources of organic contaminants.  Leaching tests may be useful tools to estimate the mobility of contaminants via the water phase and thereby the risk for groundwater and surface water contamination. The influence of soil composition (peat and clay content) on the leachability was investigated in batch leaching experiments for chemically diverse hydrophobic organic compounds (HOCs: PCP, PAHs, HCB, HCHs, PCBs, and TCDD/Fs). The above mentioned compounds were analyzed by both GC-LRMS (gas chromatography coupled with low resolution mass spectrometry (GC-HRMS) and GC-HRMS (gas chromatography coupled with high resolution mass spectrometry). Also the the leachability of eleven selected PCBs from naturally aged soil (Västervik, Sweden) was investigated in relation to the composition and concentration of dissolved organic matter at different pH (2 to 9), using a pH static test with initial acid/base addition. The the composition and of dissolved organic matter (DOM) at different pH values was explored by FTIR spectroscopy. The results were evaluated by orthogonal projections to latent structures (OPLS). Generally, for all model compounds studies, the Kd-values showed a variability of 2-3 orders of magnitude depending on the matrix composition. The Kd-values of moderately hydrophobic compounds, (e.g. HCHs, PCP and Phe), were correlated mainly with the organic matter content of soil. For more hydrophobic compounds (e.g.BaA, HCB and PCB 47), the leachability decreased as the proportions of  OM and clay contents increased. The Kd-values of 1,3,6,8-TCDD and 1,3,6,8-TCDF were  positively correlated with peat content but negatively correlated with clay content, while for PCB 153 and PCB 155 the correlations were reversed. The log Kd-values of all target PCBs decreased with increased pH values and the log Kd-values were highly correlated with the concentration of total organic carbon (TOC) in the leachates. The FTIR analysis of DOM showed that the least chlorinated and hydrophobic PCB congeners (i.e. PCB 28) might be associated with the hydrophilic fraction (i.e. carboxylic groups) of DOM. Our study demonstrated how complex interaction between the organic matter, clay components, pH and DOC influences the leachability of HOCs in a compound-specific manner.

Over the years, colorimetric reagents and immunology have been widely used in screening tests for illicit drugs; however, the test kits are not always convenient for field use and often require the user to mix and develop a specific set of reagents. In our project, we have been working on alternative platforms based on paper microfluidic devices (uPADs) for field testing. These devices utilize wax channels printed on paper to direct the analyte towards a specific set of chemical reagents. Using the procedure, we have developed a six-channel chip that adapts known colorimetric reagents targeting cocaine, opiates, amphetamines and ketamine for multiplex detection. For more sensitive and specific determinations than the colorimetric reagents, we have also developed a paper device that utilizes the interaction between gold nanoparticles and drug specific aptamers. The µPADs using colorimetric reagent are designed as a six-channel multiplexed system. Sequences of different reagents applied to each channel to produce a series of reactions and the color changes appear at the end of each channel. The entire process takes less than five minutes. The adjusted reagents produce specific color changes for seized drugs on the paper microfluidic devices. Procedures have been developed for the detection of cocaine, ketamine, codeine, ephedrine, morphine, amphetamine, methamphetamine, and MDMA. These devices have been tested for sensitivity, specificity and stability against a variety of potential interferences and test conditions. Gold nanoparticles (AuNPs)/ aptamers µPADs were developed to detect cocaine. The presence of cocaine cause the binding with aptamers, and the gold nanoparitcles produced a salt-indicated aggregations and gave a color change of AuNPs from red to black. The absence of cocaine allowed the aptamers freely to bind gold nanoparticles, and no color change occured. The device had a preliminary validation of sensitvity and specificity against a variety of potential interferences. The use of paper microfluidic devices permits the development of rapid, inexpensive and easily operated tests for drug samples in the field. They present a safe and convenient presumptive tool that can be used in the field.

Ionic-type transistors are important devices for precise chemical control and biosensing applications. Previous work by Tybrandt et al. has demonstrated a novel approach to constructing an ionic transistor using conducting polymers poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and quarternized- polyvinyl benzyl chloride (q-PVBC). This approach could be combined with the 3D stamp method of generating concentration gradients in supported lipid bilayers (SLBs) as shown by Liu et al. to create a charged lipid-based ionic polar junction transistor. An electric potential applied across the SLB would drive charged lipids towards the opposite electrode, thus generating current flow across the SLB. Incorporation of a charged-lipid functionalized PEDOT derivative as demonstrated by Johansson et al. would allow a longer period of current flow before charge carriers are depleted. Such a device could offer novel approaches to biosensing.

Designer drugs are compounds which have been synthetically derived from illicit drugs. After consumption, drugs and their metabolites are introduced into the sewage water which is treated and disposed into the environment. A combined target, suspect and non-target workflow was created to detect designer drugs in environmental water samples. Multiple water samples were spiked with an unknown mixture of drugs and metabolites to assess the efficiency of the method. Samples were collected from sewage influent and effluent pipes, downstream from a sewage outfall and reclaimed water. Analysis was conducted with high resolution MS using the QExactive Orbitrap. Screening was performed using a database compiled in-house using TraceFinder EFS. Structure confirmation was achieved using MassFrontier. Target drugs and their metabolites were detected in sewage influent but not in sewage effluent, downstream of the effluent pipe, or in reclaimed water. The workflow was adequate to detect designer drugs in multiple water matrices at concentrations as low as 20ppt.

Benzodiazepines are among the most prescribed compounds for anti-anxiety and are present in many toxicological screens. These drugs are also prominent in the commission of drug facilitated sexual assaults due their effects on the central nervous system. Due to their potency, a low dose of these compounds is often administered to victims; therefore, the target detection limit for these compounds in biological samples is 10 ng/mL. Currently these compounds are predominantly analyzed using immunoassay techniques; however more specific screening methods are needed. The goal of this dissertation was to develop a rapid, specific screening technique for benzodiazepines in urine samples utilizing surface-enhanced Raman spectroscopy (SERS), which has previously been shown be capable of to detect trace quantities of pharmaceutical compounds in aqueous solutions. Surface enhanced Raman spectroscopy has the advantage of overcoming the low sensitivity and fluorescence effects seen with conventional Raman spectroscopy. The spectra are obtained by applying an analyte onto a SERS-active metal substrate such as colloidal metal particles. SERS signals can be further increased with the addition of aggregate solutions. These agents cause the nanoparticles to amass and form hot-spots which increase the signal intensity. In this work, the colloidal particles are spherical gold nanoparticles in aqueous solution with an average size of approximately 30 nm. The optimum aggregating agent for the detection of benzodiazepines was determined to be 16.7 mM MgCl2, providing the highest signal intensities at the lowest drug concentrations with limits of detection between 0.5 and 127 ng/mL. A supported liquid extraction technique was utilized as a rapid clean extraction for benzodiazepines from urine at a pH of 5.0, allowing for clean extraction with limits of detection between 6 and 640 ng/mL. It was shown that at this pH other drugs that are prevalent in urine samples can be removed providing the selective detection of the benzodiazepine of interest. This technique has been shown to provide rapid (less than twenty minutes), sensitive, and specific detection of benzodiazepines at low concentrations in urine. It provides the forensic community with a sensitive and specific screening technique for the detection of benzodiazepines in drug facilitated assault cases.

Muskelstyrka och muskelmassa avtar med stigande ålder och är associerat med mortalitet, svaghet, osteoporos, fall och frakturer. Hos yngre individer har magnesiumtillskott signifikant ökat muskelstyrka. Det rekommenderade dagliga intaget (RDI) av magnesium enligt Nordiska näringsrekommendationer (NNR) är lägre än rekommendationen av U.S Food and Nutrition Board (FNB). Syftet med detta litteraturarbete var att studera publicerad litteratur inom ämnet magnesium och muskler med avsikt att undersöka ifall ett ökat magnesiumintag hos individer över medelåldern påverkar muskelstyrka och relativ muskelmassa samt undersöka vilka livsmedel som ur ett ekonomiskt perspektiv kan konsumeras för att bidra till att NNR´s RDI uppnås. Litteratursökning identifierade sex artiklar som var relevanta för frågeställningen ”Kan en högre dos magnesium öka muskelstyrka?”. Samma artiklar användes för ytterligare en frågeställning; ”Kan en högre dos magnesium förbättra relativ muskelmassa?”. Litteratursökning för den andra frågeställningen identifierade inte fler artiklar som var relevanta för frågeställningen. För den tredje frågeställningen ”Vilka livsmedel kan med fördel ur ett ekonomiskt perspektiv bidra till ett högre intag av magnesium?” användes information från Livsmedelsverkets livsmedelsdatabas och medelvärdet av tre livsmedelsbutikers jämförelsepriser. Sammanställningen av den forskning som finns visade att en kost som uppnår NNR´s dagsrekommendation främjar muskelstyrka men det gjorde inte ett högre intag av magnesium via kosttillskott. Ett ökat intag av både dietärt och supplementärt magnesium observerades främja relativ muskelmassa men det verkar som att dietärt magnesium har högre biotillgänglighet än magnesium i kosttillskott. De mest ekonomiska livsmedlen som kan konsumeras för att bidra till en högre dos magnesium i kosten var fullkornsprodukter som frukostflingor, pasta och hårt bröd. / Muscle strength and muscle mass declines with increasing age. This is associated with mortality, frailty, osteoporosis, falls and fractures. Magnesium supplementation has been shown to increase muscle strength significantly in young subjects. The recommended daily amount of magnesium according to Nordic nutrition recommendations (NNR) is lower than that of U.S. Food and Nutrition Board (FNB). The aim of this thesis work was to study published literature on the subject magnesium and muscle in order to investigate if an increased magnesium intake in subjects middle aged or older affects muscle strength and relative muscle mass and to evaluate which common foods contributes the most to achieve the RDI of NNR from an economic point of view. Searches identified six articles relevant to the issue “Could an increased dose of magnesium improve muscle strength?”. The same articles were used to answer a second issue; “Could an increased dose of magnesium improve relative muscle mass?”. Searches for the second issue did not yield more articles relevant to the issue. For the third issue; “Which foods has, from an economic point of view, an advantage in contributing to a higher magnesium intake?” information from the Swedish food agency´s food database was used and the mean cost from three different food chains comparison prizes. A compilation of data from the published scientific studies showed that a diet which fulfills the recommended daily amount of magnesium according to NNR promotes muscle strength in subjects middle aged or older; however, an increased amount of magnesium taken as a supplement did not show any significant increase in muscle strength. An increased intake of both dietary and supplementary magnesium promoted relative muscle mass, but the bioavailability of dietary magnesium seems to be higher than the bioavailability of supplements. The most economic groceries which contributes to a higher dose of magnesium in the diet was full grain products such as breakfast cereals, pasta and hard bread.

With increasing pressure on economical production of crops, more fertilizers are being applied to the soil each year to increase crop yields. Economical production of crops with applications of fertilizer requires an evaluation of the essential elements of the various crops so applications of fertilizer will not exceed the law of diminishing returns. Because varying soil, moisture, and climatic conditions influence the response to added fertilizers, some workers (18, 26, 38) have contended that the only reliable way of determining the fertilization needs of a crop is to conduct a trial on the particular farm. The length of time involved to determine the fertilizer requirements of a crop, along with the fact that climatic conditions change, limits the value of this method. With observation type trials, yield increases are easily over-looked and the expense involved in conducting a properly designed trial is beyond the scope of the farmers.