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Sometimes, the fact that an attitude is fitting seems like a demand to have that attitude. But in other cases, the fact that an attitude is fitting seems more like a permission to have the attitude. I defend a proposal that can accommodate both of these appearances. I argue that there is a kind of emotionlessness, which I call apathy, that can be fitting or unfitting in just the same way that emotion can. I further argue that, in some cases, it can be fitting to respond a single object either with emotion or with apathy. When both apathy and emotion are fitting options, the fittingness of the emotion is a permission-like status; failures to have the fitting emotion are not failures of fit. But when an emotion is fitting and apathy is unfitting, the fittingness of the emotion is a demand-like status; failures to have the emotion are failures of fit. [ABSTRACT FROM AUTHOR]

This paper investigates the ethics of regarding others as epistemically hopeless. To regard a person as epistemically hopeless with respect to p is, roughly, to regard her as unable to see the truth of p through rational means. Regarding a person as epistemically hopeless is a stance that has surprising and nuanced moral implications. It can be a sign of respect, and it can also be a way of giving up on someone. Whether it is morally problematic to take up this stance, I argue, depends on the choices that one faces (or is likely to face). I close the paper by arguing against the view that there are standing moral reasons against regarding others as epistemically hopeless. [ABSTRACT FROM AUTHOR]

This paper introduces a novel form of pragmatic encroachment: one that makes a difference to the status of emotion rather than the status of belief. I begin by isolating a distinctive standard in terms of which we can evaluate emotion – one sometimes called "subjective fittingness," "epistemic justification," or "warrant." I then show how this standard for emotion could face a kind of pragmatic encroachment importantly similar to the more familiar encroachment on epistemic standards for belief. Encroachment on warranted emotion is a striking proposal that deserves attention. In fact, there are good reasons to think that encroachment on warranted emotion deserves to be considered the default view for those who already accept pragmatic encroachment on the epistemic status of belief. I support this parity claim by arguing for a principle that establishes a limited coordination between the conditions that warrant emotion and the conditions that justify belief. [ABSTRACT FROM AUTHOR]

In this paper, I defend an epistemic requirement on fitting hopes and worries: it is fitting to hope or to worry that p only if one's epistemic position makes it rational to suspend judgment as to whether p. This view, unlike prominent alternatives, is ecumenical; it retains its plausibility against a variety of different background views of epistemology. It also has other important theoretical virtues: it is illuminating, elegant, and extensionally adequate. Fallibilists about knowledge have special reason to be friendly to my view; it can help them explain why it can be unfitting to hold on to hope and worry in the face of overwhelming evidence, and it can also help them explain the sense in which knowledge that p and hope that –p are in tension with one another. [ABSTRACT FROM AUTHOR]

According to the view that there is moral encroachment in epistemology, whether a person has knowledge of p sometimes depends on moral considerations, including moral considerations that do not bear on the truth or likelihood of p. Defenders of moral encroachment face a central challenge: they must explain why the moral considerations they cite, unlike moral bribes for belief, are reasons of the right kind for belief (or withheld belief). This paper distinguishes between a moderate and a radical version of moral encroachment. It shows that, while defenders of moderate moral encroachment are well-placed to meet the central challenge, defenders of radical moral encroachment are not. The problem for radical moral encroachment is that it cannot, without taking on unacceptable costs, forge the right sort of connection between the moral badness of a belief and that belief's chance of being false. [ABSTRACT FROM AUTHOR]

Call the following claim Asymmetry: rationality often requires (or permits) a more steadfast response to pure moral disagreement than it does to otherwise analogous non- moral disagreement. This paper briefly motivates Asymmetry and explores its implications for meta-ethics. Some philosophers have thought that anti- realists are better-placed than realists to explain Asymmetry because, if anti-realism is true, disagreement cannot provide evidence against the reliability of one's thinking about objective moral facts. This paper argues that this simple diagnosis fails to support otherwise plausible anti-realisms. It closes by discussing an alternative explanation for Asymmetry, which appeals to the moral importance of steadfastness. [ABSTRACT FROM AUTHOR]

This paper presents a challenge to conciliationist views of disagreement. I argue that conciliationists cannot satisfactorily explain why we need not revise our beliefs in response to certain moral disagreements. Conciliationists can attempt to meet this challenge in one of two ways. First, they can individuate disputes narrowly. This allows them to argue that we have dispute-independent reason to distrust our opponents’ moral judgment. This approach threatens to license objectionable dogmatism. It also inappropriately gives deep epistemic significance to superficial questions about how to think about the subject matter of a dispute. Second, conciliationists can individuate disputes widely. This allows them to argue that we lack dispute-independent reason to trust our opponents’ moral judgment. But such arguments fail; our background of generally shared moral beliefs gives us good reason to trust the moral judgment of our opponents, even after we set quite a bit of our reasoning aside. On either approach, then, conciliationists should acknowledge that we have dispute-independent reason to trust the judgment of those who reject our moral beliefs. Given a conciliationist view of disagreement's epistemic role, this has the unattractive result that we are epistemically required to revise some of our most intuitively secure moral beliefs. [ABSTRACT FROM AUTHOR]

Many writers have recently argued that there is something distinctively problematic about sustaining moral beliefs on the basis of others’ moral views. Call this claim pessimism about moral deference. Pessimism about moral deference, if true, seems to provide an attractive way to argue for a bold conclusion about moral disagreement: moral disagreement generally does not require belief revision. Call this claim steadfastness about moral disagreement. Perhaps the most prominent recent discussion of the connection between moral deference and moral disagreement, due to Alison Hills, uses pessimism about the former to argue for steadfastness about the latter. This paper reveals that this line of thinking, and others like it, are unsuccessful. There is no way to argue from a compelling version of pessimism about moral deference to the conclusion of steadfastness about moral disagreement. The most plausible versions of pessimism about moral deference have only very limited implications for moral disagreement. [ABSTRACT FROM AUTHOR]

Subject-sensitive invariantism posits surprising connections between a person's knowledge and features of her environment that are not paradigmatically epistemic features. But which features of a person's environment have this distinctive connection to knowledge? Traditional defenses of subject-sensitive invariantism emphasize features that matter to the subject of the knowledge-attribution. Call this pragmatic encroachment. A more radical thesis usually goes ignored: knowledge is sensitive to moral facts, whether or not those moral facts matter to the subject. Call this moral encroachment. This article argues that, insofar as there are good arguments for pragmatic encroachment, there are also good arguments for moral encroachment. [ABSTRACT FROM AUTHOR]

A data breach occurs when sensitive data records from an organization are released either intentionally or unintentionally to an untrusted environment. This research examines mega breaches, data breaches that constitute the loss of a million records or more, and how organizations have responded to recent mega breaches. Data from 2,273 data breaches that occurred between 2005 and 2015 that involved the confirmed loss of records are analyzed. This data is used to examine recent trends in the occurrences of mega breaches as well as the different categories of breaches and the different entities affected by breaches. In addition, this research examines methods that can be employed by organizations in order to prevent data breaches, such as encryption and employee training. [ABSTRACT FROM AUTHOR]

Abstract: A background electrolyte for capillary electrophoresis containing tris(-hydroxymethyl) aminomethane (THAM) and ethanesulfonic acid (ESA) gives excellent efficiency for separation of drug cations with actual theoretical plate numbers as high as 300,000. However, the analyte cations often elute too quickly and consequently offer only a narrow window for separation. The best way to correct this is to induce a reverse electroosmotic flow (EOF) that will spread out the peaks by slowing their migration rates, but this has always been difficult to accomplish in a controlled manner. A new method for producing a variable EOF is described in which a low variable concentration of tributylammonium- or triethylammonium ESA is added to the BGE. The additive equilibrates with the capillary wall to give it a positive charge and thereby produce a controlled opposing EOF. Excellent separations of complex drug mixtures were obtained by this method. [Copyright &y& Elsevier]

Abstract: Methods for separation of ions by ion-exchange, ion-pair, and zwitterion ion chromatography share at least one common thread – the induced formation of a cation–anion pair in the stationary phase. Selectivity can be defined as the relative ability of sample ions to form such a pair. Examples are given in anion-exchange chromatography to show the effect of variations in the geometry, bulkiness and polarity of the resin cation on selectivity. The type of resin matrix, the hydrophobic nature of the resin surface and the degree of solvation also affect chromatographic behavior. The selectivity series observed in ion chromatography seems to be best explained by the interplay of two components: electrostatic attraction (ES) and the enforced-pairing (EP) that is brought about by hydrophobic attraction and by water-enforced ion pairing. Selectivity in ion-pair chromatography (IPC) and in zwitterion ion chromatography (ZIC) is affected by both the mobile phase cation and anion. This leads to elution orders for anions that are different from conventional ion-exchange chromatography (IC) of anions where cations are excluded from the stationary phase and have little effect on a separation. The elution order of anions in ZIC is similar to that in IC except for small anions of 2− charge, which are retained more weakly in ZIC. A unique advantage of ZIC is that sample ions can be eluted as ion pairs with pure water as the eluent and a conductivity detector. The mechanism for separation of anions on a zwitterionic stationary phase has been a subject for considerable debate. The available facts point strongly to a partitioning mechanism or a mixed mechanism in which partitioning is dominant with a weaker ion-exchange component. [Copyright &y& Elsevier]

This paper reports the design and ground-based testing of a multiplexed colorimetric solid-phase extraction (MC- SPE) platform for the rapid determination of multiple water quality parameters in a simple set of operational steps. Colorimetric solid-phase extraction (C-SPE) is an analytical platform that combines impregnated colorimetric reagents on a solid-phase extraction membrane and diffuse reflectance spectroscopy to quantify trace analytes in water. In extending C-SPE to MC-SPE, a filter holder that incorporates discrete analysis channels and a jig that facilitates the concurrent operation of multiple syringes have been designed, enabling the simultaneous determination of three different measures of water quality. Separate, single-parameter membranes, placed in a read-out cartridge create unique, parameter-specific addresses at the exit of each channel. Following sample exposure, the diffuse reflectance spectrum of each address is collected serially and the Kubelka-Munk function is used to quantify each water quality parameter via calibration curves. Performance evaluations of the MC-SPE platform were conducted using sample pH, silver(I), and nickel- (II). Determinations of silver(I) (0.05-0.5 ppm) and nickel(II) (1.8-5.0 ppm) follow established C-SPE methods on reversed-phase extraction membranes using 5-(p- dimethylaminobenzylidene)rhodanine and dimethyiglyoxime, respectively, as colonimetric reagents. Sample pH (2.5-5.0) is measured using an anion-exchange membrane impregnated with fluorescein. These determinations require ∼120 s to complete using a total sample volume of 3.0 mL. The extension of MC-SPE to the determination of a greater number of analytes and its potential application to space and earth-bound monitoring needs are briefly discussed. [ABSTRACT FROM AUTHOR]

Ion chromatography as we know it today was built on a foundation of knowledge accumulated over a period of many years. Here, we review some of the outstanding earlier achievements in ion-exchange chromatography. Beginning about 1947, Spedding and Powell at Iowa State published a series of papers describing practical methods for preparative separation of the rare earths by displacement ion-exchange chromatography. The same group then demonstrated the ion-exchange separation of 14N and 15N isotopes in ammonia. Beginning in the 1950s, Kraus and Nelson at Oak Ridge published numerous analytical methods for metal ions based on separation of their chloride, fluoride, nitrate or sulfate complexes by anion chromatography. In the period from about 1960 to 1980 many clever chromatographic methods for metal ion separations were reported by researchers throughout the world and automatic in-line detection was gradually introduced. A truly innovative method by Small, Stevens and Bauman at Dow Chemical Co. marked the birth of modern ion chromatography. Anions, as well as cations, could now be separated quickly and conveniently by a system of suppressed conductivity detection. A method for anion chromatography with non-suppressed conductivity detection was published by Gjerde et al. in 1979. This was followed by a similar method for cation chromatography in 1980. Ion chromatography as we know it today did not just happen. It was built on a solid foundation of knowledge that has accumulated over a period of many years. Revisiting the older ion-exchange chromatography serves not only to pay tribute to some remarkable accomplishments, but it can also be a learning experience. Trends and ideas in science tend to run in repeating cycles. Thus, an awareness of older work may provide inspiration for new research using improved contemporary technology. Selection of milestones is a rather personal matter. I chose to write about subjects of which I came to have a firsthand knowledge during my career. The topics selected are in roughly chronological order and cover the period from about 1945 to 1980. An effort has been made to explain the chemical principles as well as to recount the major accomplishments of the various research projects. [Copyright &y& Elsevier]

Colorimetric solid phase extraction (C-SPE) is an analytical technique in which analytes in water samples are extracted onto a solid adsorbent matrix impregnated with a colorimetric reagent and then quantified directly on the adsorbent surface using diffuse reflectance spectroscopy. This paper presents a further development in C-SPE. In this case, the reagent employed to detect the analyte is not impregnated on the extraction medium. Instead, the reagent is weakly immobilized on a solid support (i.e., filter paper) and released into the sample as it flows through the support. The reagent complexes the analyte in solution, forming a highly colored precipitate that is collected on the surface of an extraction membrane. The concentration of analyte is determined using the Kubelka–Munk function calculated from the diffuse reflectance spectrum of the precipitate on the membrane surface. This precipitation–spectrophotometric platform is extensively evaluated by determining nickel(II) using dimethylglyoxime (DMG) as the precipitating reagent. The ability to optimize reaction conditions with immobilized reagents by in-line buffering is also demonstrated. Specifically, borax buffer was utilized to adjust the pH of nickel(II) samples prepared in deionized water. This combination of immobilized buffer and reagent allows C-SPE to operate in a solid-phase mode in which all the reagents requisite for optimal analyte determination are immobilized on solid supports. Using this method, nickel(II) was determined in a single processing step over the concentration range 0.50–5.0 ppm in ∼40 s with 1.0 ml sample volumes. [Copyright &y& Elsevier]

We introduce colorimetric solid-phase extraction (C-SPE) for the rapid determination of selected ions. This new technique links the exhaustive concentration of an analyte by SPE onto a membrane disk surface for quantitative measurement with a hand-held diffuse reflectance spectrometer. The concentration/measurement procedure is complete in ∼1 min and can be performed almost anywhere. This method has been used to monitor iodine and iodide in spacecraft water in the 0.1–5.0 ppm range and silver(I) in the range of 5.0–1000 μg/l. Applications to the trace analysis of copper(II), nickel(II), iron(III) and chromium(VI) are described. Studies on the mechanism of extraction showed that impregnation of the disk with a surfactant as well as a complexing reagent results in uptake of additional water, which markedly improves the extraction efficiency. [Copyright &y& Elsevier]

New findings are reported on simple ways to modify an ordinary HPLC column to obtain efficient ion chromatographic (IC) separations. Permanently coating a column with an ionic surfactant is known to produce an effective column for IC. We now show that incorporation of a nonionic surfactant in the coating, or coating in separate layers, results in a dramatic reduction of ion retention times and gives sharper peaks. Dynamic coating by incorporating a small amount of an alcohol, diol or zwitterion in the aqueous mobile phase permits good separations of alkanecarboxylic acids. A mobile phase containing a quaternary ammonium cation and a zwitterion anion provides excellent separations of common anions on a silica C18 column. An aqueous eluent containing a mixture of a zwitterion 4-(2-hydroxyethyl) acid and methanesulfonic acid can be used in conjunction with a standard cation exchange column. After passing through a membrane suppressor, the mobile phase has a slightly acidic pH, permitting divalent transition metal ions (as well as others) to be detected by conductivity. [Copyright &y& Elsevier]

A straight-chain alcohol or diol additive in the mobile phase was used to modify and improve the HPLC separation of organic acids and bases. Incorporation of 2% 1-butanol, 1% 1,2-hexanediol, or 0.25% 1,2-octanediol into an aqueous mobile phase greatly improved the separation of alkane carboxylic acids on a silica C18 column, both in terms of separation time and peak shape. When 1.5% 1-hexanol, 0.09% 1-decanol or 0.01% 1-dodecanol was added to an acetonitrile–water (30:70) mobile phase, much sharper peaks and better resolution were obtained for aromatic bases separated on an underivatized polystyrene–divinylbenzene column. The mobile phase additive is believed to coat the stationary phase surface by a dynamic equilibrium. The coated surface is more hydrophilic and facilitates the efficient partitioning of analytes between the mobile and stationary phases. [Copyright &y& Elsevier]

One of the problems with capillary electrophoresis is a lack of versatility regarding manipulation of the separation selectivity. A new and potentially universal concept is to introduce an ion-exchange component into a separation so that the migration of analyte ions is influenced by both their electrophoretic mobilities and their chromatographic properties. This may be accomplished by use of capillaries filled with or coated with solid ion-exchange polymers, or by addition of a soluble ionic polymer to the background electrolyte to create a pseudo-stationary phase. While each of these methods achieves the same result, they are not competitive, but rather complementary as the problems associated by one approach are overcome by the others. Recent highlights in the field are used to illustrate the flexibility that this approach provides to electrophoretic separation of ions. [Copyright &y& Elsevier]

States that separations by means of capillary electrophoresis (CE) were conveniently conducted in an aqueous-organic solution at hydrogen ion concentration of 2.4, in which the electroosmotic flow (EOF) compared to the electrophorectic migration. Information on the use of CE in various applications; Reference to the application of micelle electrokinetic chromatography (MECK).

Discusses the separation of neutral organic compounds by capillary electrophoresis using a negatively charged additive called Brij-S. Examples of other system used as a surfactant; Limitations of micellar electrokinetic capillary chromatography; Synthesis of sodium Brij-S sulfate; Preparation and properties of Brij-S; Effect of experimental variables.

Studies mixed surfactants as mobile phase additives for the separation of organic compounds by HPLC. Concentration of surfactants; Reduction of the capacity factors of organic analytes; Use of binary additive systems; Effectiveness of ternary mixture of additives.

Studies the capillary zone electrophoresis (CZE) of nonionic compounds using a novel anionic surfactant additive. Principles; Effect of pH; Effect of applied voltage; Effect of acetonitrile concentration; Effect of sodium dioctyl sulfosuccinate (DOSS) concentration.

Studies eluent modifiers for the liquid chromatographic separation of carboxylic acids using conductivity detection. Reagents and chemicals; Effect of organic modifiers; Effects of resin sulfonation; Quantitative chromatographic determinations; Attempted separation of sulfonic acids.

Guided by Honig and Hatch’s conceptualization of bridging and buffering, we analyzed the first teacher collective bargaining agreements negotiated after the enactment of the Ohio Teacher Evaluation System to understand how state law has shaped provisions for teacher evaluation, compensation, reductions in force (RIF), transfers, and contract renewal. We found surprising variation in provisions across districts. Most notable was how districts defined comparable evaluations in making RIF decisions. Bridging districts provided the greatest protections for the most accomplished teachers, regardless of seniority. In contrast, buffering districts have RIF provisions based on seniority. [ABSTRACT FROM AUTHOR]

Abstract: Formaldehyde has been detected in drinking water supplies across the globe and on board NASA spacecraft. A rapid, simple, microgravity-compatible technique for measuring this contaminant in water supplies using colorimetric-solid phase extraction (C-SPE) is described. This method involves collecting a water sample into a syringe by passage through a cartridge that contains sodium hydroxide, to adjust pH, and Purpald, which is a well-established colorimetric reagent for aldehydes. After completing the reaction in the syringe by agitating for 2min on a shaker at 400rpm, the 1.0-mL alkaline sample is passed through an extraction disk that retains the purple product. The amount of concentrated product is then measured on-disk using diffuse reflectance spectroscopy, and compared to a calibration plot generated from Kubelka–Munk transformations of the reflectance data at 700nm to determine the formaldehyde concentration. This method is capable of determining formaldehyde concentrations from 0.08 to 20ppm with a total work-up time of less than 3min using only 1-mL samples. [Copyright &y& Elsevier]

Abstract: There is an increasing need to know the concentrations of chromium(III) and (VI) separately rather than only the total chromium content. A method is described for accomplishing this very quickly using only low-cost, portable equipment. Two small, resin-loaded extraction disks are placed one on top of the other in a plastic holder. Then a syringe containing the aqueous sample is attached to the holder and the sample is pushed through the disks. In a matter of seconds, all of the chromium(VI) is retained on the top anion-exchange disk and chromium(III) is extracted by the second cation-exchange disk. The concentrations on each disk are several hundredfold higher than they were in the original sample. The amounts of chromium(III) and (VI) extracted are measured directly on the surface of the respective disks by diffuse reflectance spectroscopy (DRS). Despite the low molar absorptivity of chromium(III) in aqueous solution, the concentration on the upper most layer on the extraction disk is high enough to permit the determination of chromium(III) in samples at the low mg/L range. Chromium(VI) can also be determined at low to sub-mg/L concentrations. A study of the cation-exchange disks was undertaken to compare the performance characteristics of disks containing sulfonated resins and those with iminodiacetate functionality. In addition, data are presented to show the effects of heating the iminodiacetate disks after the initial extraction. The disks were heated in hot water for 15–30min to complete the slow complexation reaction on the surface. [Copyright &y& Elsevier]

Abstract: Novel monolithic disks were prepared via ring opening metathesis polymerization (ROMP) from norborn-2-ene (NBE), a crosslinker, i.e., 1,4,5,8,8a-hexahydro-1,4,4,5,8, exo, endo-dimethanonaphthalene (DMN-H6) and tris(norborn-5-ene-2-ylmethylenoxy)methylsilane, respectively, 2-propanol and toluene (25:25:41:9, all %, w/w) using RuCl2(PCy3)2(CHPh) (Cy=cyclohexyl) as initiator and triphenylphosphine (PPh3) as modulator. Disks 1–2mm thick were prepared by polymerization in a mold, disks thinner than 1mm were prepared by impregnation of nylon or other porous filters prior to the polymerization step. These disks were evaluated for the preconcentration of iodine and selected organic solutes from dilute aqueous samples by solid-phase extraction (SPE). Quantitative measurement of the extracted solutes was achieved by diffuse-reflectance spectroscopy (DRS) directly on the surface of the disk. [Copyright &y& Elsevier]

Abstract: Colorimetric solid-phase extraction (C-SPE) is an integrated technique in which an analyte is selectively concentrated onto a disk and then quantitated by diffuse reflectance spectroscopy. This paper describes the results of an investigation that applies the concept of negligible depletion (ND) to C-SPE, representing the first application of ND concepts to solid-phase extractions. The approach relies on passing the minimal volume of sample through the disk required to reach an equilibrium in which the concentration of analyte in the sample entering and exiting the disk are equal. At this point, the amount of analyte extracted by the disk is proportional to the sample concentration but is independent of the sample volume passed through the disk. With this new method, called C-SPE/ND, the precise measurement of sample volume is no longer necessary. The work herein details the general principles of this new methodology, and validates its basic tenets in an investigation of the extraction of the organic dye methyl violet. The analytical capabilities of C-SPE/ND are then demonstrated by its application to measurements of iodine. Iodine is a biocide increasingly used as a simple and effective disinfectant for water in locations where municipal water treatment systems are potentially compromised. Thus, the ability to operate C-SPE in an ND mode notably enhances the broad-based utility of this methodology as a reliable and an easy-to-use analysis tool for water quality assessments. Since iodine is also the biocide used on NASAs Space Shuttle, C-SPE/ND has the potential to overcome problems associated with the removal of air bubbles entrapped in a water sample in the microgravity environment encountered in space exploration. Extensions of C-SPE/ND to facile determinations of other water quality parameters with respect to both earth- and space-based needs are briefly discussed. [Copyright &y& Elsevier]

Abstract: A background electrolyte (BGE) containing a 100mM concentration of an alkylammonium cation with ethyl, propyl or butyl groups provides an excellent medium for separation of anions by capillary electrophoresis (CE). Two major effects were noted. Use of one of a series of alkylammonium cations in the BGE at a selected pH provides a simple and effective way to vary and control electroosmotic flow (EOF) over a broad range. It is believed that the alkylammonium cations are coated onto the capillary surface through a reversible dynamic equilibrium. Secondly, alkylammonium cations modify the electrophoretic migration of sample anions and the electroosmotic migration of neutral organic analytes by association interaction. This selective interaction results in improved anion separations and permits the simultaneous separation of neutral analytes. The degree of association interaction varies with the bulk and hydrophobicity of the alkylammonium cations. Incorporation of an aliphatic amine salt of moderate molecular weight in the running electrolyte provides a valuable new way to vary the migration times of sample anions and to optimize their resolution. The interactions between alkylammonium cations and sample anions or neutral organics appear to take place entirely within the liquid phase and do not require a polymeric or micellar pseudo phase. [Copyright &y& Elsevier]

Colorimetric solid-phase extraction (C-SPE) has been previously explored as a means to monitor the iodine-based disinfectant used in the water systems on board the space shuttle. This same disinfectant is baselined for eventual deployment in the US water recovery system planned for node 3 of the International Space Station (ISS). With C-SPE, the I2 concentration is determined from the diffuse reflectance spectrum (DRS) of the yellow iodine–poly(vinylpyrrolidone) (PVP) complex using the Kubelka–Munk function. However, the solution chemistry of iodine is very complex and results in a variety of inorganic species (e.g., I−, I2, I3−, HOI) that have very different biocidal capabilities. Thus, the nature of the interaction of iodine with PVP, and more specifically, the identity of the iodine species involved in the interaction, requires more elucidation. This paper reports the findings from a series of detailed experiments conducted to elicit a more complete understanding of the iodine–PVP system employed in C-SPE. The results indicate that I2, one of the two dominant biocidal forms of iodine, is the species responsible for the analytical signal in our C-SPE platform. These findings lay the ground work for the planned development of a multiplexed iodine determination and speciation platform for in-flight analysis of spacecraft water samples. [Copyright &y& Elsevier]

Inorganic and organic anions can be separated on an ordinary silica C18 column using a mobile phase containing tetrabutylammonium hydroxide (TBAH) and an aminosulfonic acid zwitterion reagent (MOPS). The pH of this eluent is close to 7 and the background conductivity is about 50 μS, which is low enough to permit anion analyte detection by direct conductivity. Linear calibration curves were obtained for the six anions studied and detection limits ranged from 0.075 to 0.15 mg/l (ppm) for the five inorganic anions. The method was applied to the determination of water-soluble anions in aerosol samples at concentrations as low as 0.3 mg/l. [Copyright &y& Elsevier]

A rapid, highly sensitive two-step procedure for the trace analysis of silver(I) is described. The method is based on: (1) the solid-phase extraction (SPE) of silver(I) from a water sample onto a disk impregnated with a silver-selective colorimetric reagent, and (2) the determination of the amount of complexed analyte extracted by the disk by diffuse reflectance spectroscopy (DRS). This method, called colorimetric–solid-phase extraction (C–SPE), was recently shown effective in determining low concentrations (0.1–5.0 mg/ml) of iodine and iodide in drinking water. This report extends C–SPE to the trace (∼4 μg/l) level monitoring of silver(I) which is a biocide used on the International Space Station (ISS). The determination relies on the manually driven passage of a water sample through a polystyrene–divinylbenzene disk that has been impregnated with the colorimetric reagent 5-(p-dimethylaminobenzylidene) rhodanine (DMABR) and with an additive such as a semi-volatile alcohol (1,2-decanediol) or nonionic surfactant (Brij 30). The amount of concentrated silver(I) is then determined in a few seconds by using a hand-held diffuse reflectance spectrometer, with a total sample workup and readout time of ∼60 s. Importantly, the additive induces the uptake of water by the disk, which creates a local environment conducive to silver(I) complexation at an extremely high concentration factor (∼800). There is no detectable reaction between silver(I) and impregnated DMABR in the absence of the additive. This strategy represents an intriguing new dimension for C–SPE in which additives, directly loaded in the disk material, provide a means to manipulate the reactivity of the impregnated reagent. [Copyright &y& Elsevier]

Columns suitable for use in anion chromatography can be prepared by coating a packed reversed-phase HPLC column (C18 silica or polystyrene particles) with a cationic surfactant. The efficiency is improved dramatically by first coating the column with a nonionic surfactant and then subsequently with the cationic surfactant. The thickness of the first coated layer as well as the chemical structure of the surfactant have a major effect on the column performance. Actual separations are included to demonstrate the convenience and practical use of the coated columns. Using this approach, columns with 12 900 theoretical plates for the 15-cm column (or 86 000 plates/m) were produced, giving well shaped peaks with an average asymmetry factor of 1.09. The coated layers were found to be stable, giving retention times with an average relative standard deviation of 1.6% for 12 consecutive runs. [Copyright &y& Elsevier]

Describes a methodology for trace analysis of iodine and iodide using solid-phase extraction. Adaptability of the method to a wide range of analytes; Determination of the amount of iodine using a hand-held diffuse reflectance spectrometer; Calculation of the iodide concentration from the difference in iodine levels.

Examines the mechanism of separation in electrostatic ion chromatography. Effects of mobile-phase anion and cation on analytes retention; Development of electro-osmotic flow measurements; Impact of Donnan membrane on analyte anions.

Abstract: Simple, reliable and sensitive analytical methods to determine the anions, such as fluoride, monofluorophaosphate, glycerophosphate related to anticaries are necessary for basic investigations of anticaries and quality control of dentifrices. A method for the simultaneous determination of organic acids, organic anions and inorganic anions in the sample of commercial toothpaste is proposed. Nine anions (fluoride, chloride, nitrite, nitrate, sulfate, phosphate, monofluorophaosphate, glycerophosphate and oxalic acid) were analyzed by means of ion chromatography using a gradient elution with KOH as mobile phase, IonPac AS18 as the separation column and suppressed conductivity detection. Optimized analytical conditions were further validated in terms of accuracy, precision and total uncertainty and the results showed the reliability of the IC method. The relative standard deviations (RSD) of the retention time and peak area of all species were less than 0.170 and 1.800%, respectively. The correlation coefficients for target analytes ranged from 0.9985 to 0.9996. The detection limit (signal to noise ratio of 3:1) of this method was at low ppb level (<15ppb). The spiked recoveries for the anions were 96–103%. The method was applied to toothpaste without interferences. [Copyright &y& Elsevier]

Abstract: A single-column method for the simultaneous determination of common cations and transition metals in real samples is proposed in this paper. Eleven cations (copper, lithium, sodium, ammonium, potassium, cobalt, nickel, magnesium, calcium, strontium and zinc) were separated and analyzed by means of ion chromatography using an isocratic elution with 2.5mM methane sulfonic acid and 0.8mM oxalic acid as mobile phase, IonPac SCS1 (250mm×4mm I.D.) as the separation column and non-suppressed conductor detection. Optimized analytical conditions were further validated in terms of accuracy, precision and total uncertainty and the results showed the reliability of the IC method. The relative standard deviations (RSDs) of the retention time and peak area were less than 0.04 and 1.30%, respectively. The coefficients of determination for cations ranged from 0.9988 to 1.000. The method developed was successfully applied to determination of cations in samples of beer and bottled mineral water. The spiked recoveries for the cations were 94–106%. The method was applied to beer and beverage without interferences. [Copyright &y& Elsevier]

Abstract: New technology is reported here for the synthesis of an effective weak acid–cation exchanger for ion chromatography. Monodisperse macroporous poly(ethylvinylbenzene-co-divinylbezene) (PEVB–DVB) beads of 5μm diameter were prepared by a two-step swelling and polymerization method. Then carboxyl groups were introduced by polymerization of maleic anhydride with unreacted vinyl groups on the resin beads, followed by hydrolysis of the maleic anhydride groups. A column packed with the carboxylate beads was used to separate alkali and alkaline earth metal ions in a single isocratic run. Separations were found to be better than those with similar resin particles that are simply coated with maleic acid. The columns containing the new particles were 100% compatible with solvents commonly used for HPLC. Additionally, the prepared column was stable and could be used for a long time in a wide range of pH. The column gave good resolution, low detection limits and good repeatability for the separation of common cations. Satisfactory results were also obtained for separations of organic amines and of common cations in rainwater. [Copyright &y& Elsevier]

At concentrations of 100 mM or higher the chemical nature of both the cation and anion in the background electrolyte (BGE) can be varied to manipulate the migration times of protonated aniline cations. Significant differences were noted with Li+, Na+ and K+ for capillary electrophoretic runs carried out at pH 3. However, much greater differences in migration times were observed at acidic pH values when the BGE contained protonated cations of aliphatic amines. Analyte migration became progressively slower in the series: methylamine, diethylamine, diethylamino ethanol and triethylamine. A major part of this effect was attributed to an opposing electroosmotic flow (EOF) resulting from a positively-charged coating of the capillary surface with the amine cations in the BGE via a dynamic equilibrium. The amine cations also interact in solution with the analyte ions to reduce their electrophoretic mobilities. Migration times of anilines could be varied systematically over a broad range according to the BGE amine cation selected. Excellent separations of seven closely-related anilines were obtained with the new system. [Copyright &y& Elsevier]

In this study, an aqueous solution consisting of benzoic acid with low background conductivity and β-cyclodextrin (β-CD) of hydrophilic nature and the inclusion effect to benzoic acid were used as eluent for the ion-exclusion chromatographic separation of aliphatic carboxylic acids with different pKa values and hydrophobicity on a polymethacrylate-based weakly acidic cation-exchange resin in the H+ form. With increasing concentration of β-cyclodextrin in the eluent, the retention times of the carboxylic acids decreased due to the increased hydrophilicity of the polymethacrylate-based cation-exchange resin surface from the adsorption of OH groups of β-cyclodextrin. Moreover, the eluent background conductivity decreased with increasing concentration of β-cyclodextrin in 1 mM benzoic acid, which could result in higher sensitivity for conductimetric detection. The ion-exclusion chromatographic separation of carboxylic acids with high resolution and sensitivity was accomplished successfully by elution with a 1 mM benzoic acid–10 mM cyclodextrin solution without chemical suppression. [Copyright &y& Elsevier]

A new approach to ion-exclusion chromatography (IEC) is proposed to overcome the relatively poor conductivity detection response which occurs in IEC on when acids are added to the eluent in order to improve peak shape. This approach, termed vacancy IEC, requires the sample to be used as mobile phase and a sample of water to be injected onto a polystyrene/divinylbenzene (PS/DVB)-based strongly acidic cation-exchange column (TSKgel SCX). Vacancy peaks for each of the analytes appear at the retention times of these analytes. Highly sensitive conductivity detection is possible and sharp, well-shaped peaks are produced, leading to efficient separations. Retention times were found to be affected by the concentration of the analytes in the eluent, and also by the presence of an organic modifier, such as butanol in the mobile phase. Detection limits for oxalic, formic, acetic, propionic, butyric and valeric acids at S/N=3 were 0.04, 0.1, 0.47, 0.66, 0.71 and 0.82 μM, respectively, and linear ranges for some acids extended over two-orders of magnitude. Precision values for retention times were <0.57% and for peak height were <2.06%. [Copyright &y& Elsevier]

In this preliminary study, a new approach to ion-exclusion chromatography is proposed to overcome the relatively poor conductivity detection response which occurs in ion-exclusion chromatography when acids are added to the eluent in order to improve peak shape. This approach, termed vacancy ion-exclusion chromatography, requires the sample to be used as eluent and a sample of water to be injected onto a weakly acidic cation-exchange column (TSKgel OApak-A). Vacancy peaks for each of the analytes appear at the retention times of these analytes. Highly sensitive conductivity detection is possible and sharp, well-shaped peaks are produced, leading to efficient separations. Retention times were found to be affected by the concentration of the analytes in the eluent, and also by the presence of an organic modifier such as methanol in the eluent. Detection limits for oxalic, formic, acetic, propionic, butyric and valeric acids were 0.1, 0.2, 0.3, 0.3, 0.4 and 0.5 μM, respectively, and linear ranges for some acids extended over two orders of magnitude. Precision values for retention times were 0.21% and for peak areas were <1.90%. The vacancy ion-exclusion chromatography method was found to give detection responses four to 10 times higher than conventional ion-exclusion chromatography using sulfuric acid eluent and two to five times higher than conventional ion-exclusion chromatography using benzoic acid eluent. [Copyright &y& Elsevier]

An ion chromatographic (IC) method is reported for simultaneous determination of total acidity (H+), Ba2+, Ca2+, and Mg2+ in aqueous samples. A standard ODS silica column modified by coating with n-hexadecylphosphocholine was used as the separation column. Water alone was used as the eluent, with conductivity detection of the sample ions. An excess of sodium iodide was added to each sample so that both H+ and divalent cations were always eluted with iodide as the counterion. The elution order was Ba2+, Mg2+, Ca2+, and H+ with H+ being eluted much later than the divalent cations. Acetic acid and several other weak acids could also be separated because all the protons were transposed from acetic acid (HAc) to HI by the sodium iodide. Detection limits for 100 μl injection, S/N=3 were in the low micromolar range for the divalent cations and approximately 0.3 mM for H+/I−. This method was used successfully for simultaneous determination of total acidity, magnesium and calcium in HCl-type of hot-spring water. [Copyright &y& Elsevier]