Field Analytical Chemistry and Technology最新文献

{"title":"The bubble stripping method for determining dissolved hydrogen (H2) in well water","authors":"D. M. McInnes, D. Kampbell","doi":"10.1002/1520-6521(2000)4:6<283::AID-FACT40>3.0.CO;2-V","DOIUrl":"https://doi.org/10.1002/1520-6521(2000)4:6<283::AID-FACT40>3.0.CO;2-V","url":null,"abstract":"The bubble stripping method was developed for use at field sites to measure the concentration of dissolved hydrogen (H2) in ground water. This information is useful in assessing the viability of employing monitored natural attenuation (MNA) as a strategy to influence the restoration of sites contaminated with chlorinated solvents. In laboratory studies, a reservoir containing water was employed to simulate a well. The system was constructed so that the concentration of dissolved H2 could be maintained at a constant level. The method was applied by pumping water from the reservoir into a sample cell, and then injecting 20 ml of nitrogen into the cell to produce a headspace (the “bubble”). Stripping was accomplished by pumping water through the cell, which produced agitation between the aqueous phase and the headspace. Pumping was continued for a length of time sufficient for dissolved H2 to partition between the two phases. Analysis of H2 in the headspace by gas chromatography enabled the concentration of dissolved H2 in solution to be calculated with the use of Henry's law. Two sample cell designs were compared in this study, the Microseeps Cell and the Chapelle Cell. Kinetics of equilibration studies were conducted with each cell, employing solution flow rates of 200, 300, and 400 ml/min, at 4 and 21 °C. The Microseeps Cell compared favorably with the Chapelle Cell with regards to kinetics of equilibration, with the added benefit of costing significantly less. © 2000 John Wiley & Sons, Inc. Field Analyt Chem Technol 4: 283–296, 2000","PeriodicalId":12132,"journal":{"name":"Field Analytical Chemistry and Technology","volume":"1 1","pages":"283-296"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86688126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design considerations in field‐portable GC‐based hyphenated instrumentation","authors":"Neil S. Arnold, J. Dworzanski, S. A. Sheya, W. Mcclennen, H. Meuzelaar","doi":"10.1002/1520-6521(2000)4:5<219::AID-FACT2>3.0.CO;2-7","DOIUrl":"https://doi.org/10.1002/1520-6521(2000)4:5<219::AID-FACT2>3.0.CO;2-7","url":null,"abstract":"The use of hyphenated GC-based methods in the development of portable chemical-monitoring instruments can offer considerable advantages to the instrument maker. Foremost among these advantages are specificity, speed, and lower costs. In this article, the authors describe the basis for achieving these advantages using examples of three prototype and breadboard instruments developed in their laboratories and give an extended theoretical discussion of the basis for what has been called “transfer-line GC” or TLGC. This TLGC approach to fixed pressure drop chromatography can be used to illustrate overall theoretical limitations of various approaches to high-speed GC for real-time monitoring applications. The three example instruments are a “roving” automated vapor sampling (AVS) TLGC/MS instrument, a breadboard AVS-TLGC/IMS (ion mobility spectrometry) instrument, and a breadboard AVS-TLGC/GC instrument. Discussion will include the application of TLGC theory to instrument design and will use example analyses that focus on the eventual application of this technology to the near real-time detection of highly toxic chemical vapors. © 2000 John Wiley & Sons, Inc. Field Analyt Chem Technol 4: 219–238, 2000","PeriodicalId":12132,"journal":{"name":"Field Analytical Chemistry and Technology","volume":"21 1","pages":"219-238"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75929195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring volatile organic compounds in ambient air inside and outside buildings with the use of a radio-frequency-based ion-mobility analyzer with a micromachined drift tube","authors":"G. Eiceman, E. Nazarov, B. Tadjikov, R. A. Miller","doi":"10.1002/1520-6521(2000)4:6<297::AID-FACT50>3.0.CO;2-H","DOIUrl":"https://doi.org/10.1002/1520-6521(2000)4:6<297::AID-FACT50>3.0.CO;2-H","url":null,"abstract":"A radio-frequency-based ion-mobility analyzer with a micromachined drift tube was operated continuously to monitor volatile organic compounds (VOCs) in ambient air inside a building and in an open space near the union of I-10 and I-25 at Las Cruces, New Mexico. Air was drawn directly, without enrichment or preseparation, through the analyzer, which was regulated to 35 °C. The ion source was a photo-discharge lamp at 10.6 eV, providing a preliminary level of selectivity in response to chemicals with low ionization potentials. The compensation voltage was scanned continuously from −40 to +20 V at rates of 60 V/s, providing profiles of ions obtained from VOCs in air. Solvents were detected at 1-ppm levels as fugitive emissions from other experiments under way in the laboratory from 8:00 a.m. to 6:00 p.m. However, patterns in VOC levels from 1 to 5 ppb between 6:00 p.m. and 7:00 a.m. and on weekends was attributed to air exchange between ambient air and the ventilation system of the building. The mobility analyzer results were consistent with VOCs from traffic on major city thoroughfare adjacent to the building. In-field studies near two interstate highways demonstrated that analyzer response could be correlated to traffic patterns and exhibited diurnal trends. These findings demonstrate the concept and practice of micromachined mobility analyzers as continuous monitors for VOCs as airborne vapors in buildings and on site. © 2000 John Wiley & Sons, Inc. Field Analyt Chem Technol 4: 297–308, 2000","PeriodicalId":12132,"journal":{"name":"Field Analytical Chemistry and Technology","volume":"63 1","pages":"297-308"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77716531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Field determination of trace molybdenum in river‐water samples by a visual catalytic method","authors":"S. Kawakubo, K. Ogihara, Masanobu Watanabe, M. Iwatsuki","doi":"10.1002/(SICI)1520-6521(1999)3:1<29::AID-FACT4>3.0.CO;2-#","DOIUrl":"https://doi.org/10.1002/(SICI)1520-6521(1999)3:1<29::AID-FACT4>3.0.CO;2-#","url":null,"abstract":"A sensitive visual colorimetric method has been developed for the semiquantitative field determination of trace molybdenum. The molybdenum-catalyzed oxidation of ascorbic acid at pH 3.2 in the presence of o-phenylenediamine was used as the indicator reaction, which produces yellow quinoxaline derivatives. After a fixed reaction time, the reaction is stopped by readjusting pH to 1 with hydrochloric acid. For the visual determination, the color intensity of the final solution (10 ml) for a water sample is compared to that of a color standard solution containing 0.04 μg (4 μg l−1) of MoVI prepared by the same procedure. Two handmade cells of the same size with 10-, 20-, 30- and 40-mm light paths are used in the color comparison for a wide determination range (0.005–0.2 μg). The intensity of the color standard is held constant by the adjustment of the reaction time, for example, 10 min at 25 °C, with the use of a simple relationship between the reaction time and the field temperature. Molybdenum down to 1 μg l−1 in a 4-ml river-water sample was determined without any special instrument. Analytical performances were evaluated and compared with those obtained by the spectrophotometric measurements. The application to field survey has revealed the distribution of molybdenum concentration along the river streams and a polluted point. ©1999 John Wiley & Sons, Inc. Field Analyt Chem Technol 3:29–35, 1999","PeriodicalId":12132,"journal":{"name":"Field Analytical Chemistry and Technology","volume":"52 1","pages":"29-35"},"PeriodicalIF":0.0,"publicationDate":"1999-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89602511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biological agent detection with the use of an airborne biosensor","authors":"G. Anderson, Keeley D. King, D. Cuttino, J. P. Whelan, F. Ligler, J. F. Mackrell, C. Bovais, David K. Indyke, R. Foch","doi":"10.1002/(SICI)1520-6521(1999)3:4/5<307::AID-FACT9>3.0.CO;2-M","DOIUrl":"https://doi.org/10.1002/(SICI)1520-6521(1999)3:4/5<307::AID-FACT9>3.0.CO;2-M","url":null,"abstract":"The ability to identify aerosolized bacteria remotely with the use of a small unpiloted, all-electric aircraft was demonstrated. Swallow, an aircraft custom-built for the purpose of air-particle collection, was catapult-launched, flown by line of sight for 20-min missions, and recovered by landing on a short runway. Once airborne, the sensor payload, which included a particle collector, fluidics control unit, and biosensor, was activated. The sensor utilized was the Analyte 2000 fiber optic biosensor, which performs four simultaneous fluorescent sandwich immunoassays on the surface of tapered optical probes. Five-minute test cycles were conducted continuously and monitored at the ground station until the plane returned. Then Swallow and its sensor payload could be ready for additional flights within 30 min of landing. During the trial, Swallow successfully collected and identified an aerosolized bacterial sample. © 1999 John Wiley & Sons, Inc.* Field Analyt Chem Technol 3: 307–314, 1999","PeriodicalId":12132,"journal":{"name":"Field Analytical Chemistry and Technology","volume":"5 1","pages":"307-314"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88654770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Applications of flow cytometry for the detection and characterization of biological aerosols","authors":"S. Sincock, H. Kulaga, M. Cain, Patricia R. Anderson, P. Stopa","doi":"10.1002/(SICI)1520-6521(1999)3:4/5<291::AID-FACT8>3.0.CO;2-5","DOIUrl":"https://doi.org/10.1002/(SICI)1520-6521(1999)3:4/5<291::AID-FACT8>3.0.CO;2-5","url":null,"abstract":"Flow cytometry (FCM), unlike conventional forms of spectroscopy, allows one to interrogate individual members of a sample population for size, shape, biological, and/or chemical properties. Over the past several years, we have investigated the use of flow cytometry to detect and identify microorganisms in aerosols. The effort to date has shown that changes in scatter patterns or DNA composition suggest that changes in the ambient air are evident. The use of macromolecular dyes and antibodies tagged by fluorescence can be used to identify specific components in the aerosol. Moreover, it is possible to combine several of these modes into one step. The assays presented here take 5 min or less to perform. Strategies for the use of flow cytometry to characterize biological aerosols will be discussed. Both laboratory and field studies that demonstrate the potential use of FCM as a means to detect and characterize microbiological materials in aerosols are discussed. © 1999 John Wiley & Sons, Inc.* Field Analyt Chem Technol 3: 291–306, 1999","PeriodicalId":12132,"journal":{"name":"Field Analytical Chemistry and Technology","volume":"5 1","pages":"291-306"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72638007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Real-time measurement of fluorescence spectra from single airborne biological particles","authors":"S. C. Hill, R. Pinnick, S. Niles, Yong-le Pan, S. Holler, R. Chang, J. Bottiger, Bean T. Chen, C. Orr, G. Feather","doi":"10.1002/(SICI)1520-6521(1999)3:4/5<221::AID-FACT2>3.0.CO;2-7","DOIUrl":"https://doi.org/10.1002/(SICI)1520-6521(1999)3:4/5<221::AID-FACT2>3.0.CO;2-7","url":null,"abstract":"Improved real-time methods for characterizing airborne biological particles are needed. Here we review our efforts in developing techniques for measuring the laser-induced fluorescence (total and spectrally dispersed) of individual airborne particles, and describe our present system, which can measure fluorescence spectra of single micrometer-sized bioaerosol particles with good signal-to-noise ratios. We demonstrate the capability of this system by showing measured spectra of a variety of airborne particles generated in the laboratory from road dust, ammonium sulfate, Bacillus subtilis and other bacteria prepared under various conditions, allergens, cigarette smoke, and chicken-house dust. These spectra illustrate the capability of the system to distinguish between some biological and nonbiological aerosols, and among several types of laboratory-generated biological aerosols. We suggest improvements needed to make our system field portable. © 1999 John Wiley & Sons, Inc.* Field Analyt Chem Technol 3: 221–239, 1999","PeriodicalId":12132,"journal":{"name":"Field Analytical Chemistry and Technology","volume":"191 1","pages":"221-239"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83063862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Field detection of bacillus spore aerosols with stand‐alone pyrolysis–gas chromatography–ion mobility spectrometry","authors":"A. Snyder, W. Maswadeh, J. Parsons, A. Tripathi, H. Meuzelaar, J. Dworzanski, Man-Goo Kim","doi":"10.1002/(SICI)1520-6521(1999)3:4/5<315::AID-FACT10>3.0.CO;2-2","DOIUrl":"https://doi.org/10.1002/(SICI)1520-6521(1999)3:4/5<315::AID-FACT10>3.0.CO;2-2","url":null,"abstract":"A commercially available, hand-held chemical vapor detector was modified to detect gram-positive Bacillus subtilis var. globigii spores (BG) in outdoor field scenarios. An airborne vapor monitor (AVM) ion mobility spectrometry (IMS) vapor detector was interfaced to a biological sample processing and transfer introduction system. The biological sample processing was accomplished by quartz tube pyrolysis (Py), and the resultant vapor was transferred by gas chromatography (GC) to the IMS detector. The Py-GC/IMS system can be described as a hyphenated device where two analytical dimensions, in series, allow the separation and isolation of individual components from the pyrolytic decomposition of biological analytes. Gram-positive spores such as BG contain 5–15% by weight of dipicolinic acid (DPA), and picolinic acid is a pyrolysis product of DPA. Picolinic acid has a high proton affinity, and it is detected in a sensitive fashion by the atmospheric pressure-based IMS device. Picolinic acid occupies a unique region in the GC/IMS data domain with respect to other bacterial pyrolysis products. A 1000 to 1, air-to-air aerosol concentrator was interfaced to the Py-GC/IMS instrument, and the system was placed in an open-air, western United States desert environment. The system was tested with BG spore aerosol releases, and the instrument was remotely operated during a trial. A Met-One aerosol particle counter was placed next to the Py-GC/IMS so as to obtain a real-time record of the ambient and bacterial aerosol challenges. The presence/absence of an aerosol event, determined by an aerosol particle counter and a slit-sampler–agar-plate system, was compared to the presence/absence of a picolinic acid response in a GC/IMS data window at selected times in a trial with respect to a BG challenge. In the 21 BG trials, the Py-GC/IMS instrument experienced two true negatives and no false positives, and developed a software failure in one trial. The remaining 18 trials were true positive determinations for the presence of BG aerosol, and a limit of detection for the Py-GC/IMS instrument was estimated at approximately 3300 BG spore-containing particles. © John Wiley & Sons, Inc. Field Analyt Chem Technol 3: 315–326, 1999","PeriodicalId":12132,"journal":{"name":"Field Analytical Chemistry and Technology","volume":"23 1","pages":"315-326"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82742768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PASSIVE AND ACTIVE STANDOFF INFRARED DETECTION OF BIO-AEROSOLS","authors":"C. Gittins, L. G. Piper, W. Rawlins, W. Marinelli, J. Jensen, Agnes N. Akinyemi","doi":"10.1002/(SICI)1520-6521(1999)3:4/5<274::AID-FACT6>3.0.CO;2-E","DOIUrl":"https://doi.org/10.1002/(SICI)1520-6521(1999)3:4/5<274::AID-FACT6>3.0.CO;2-E","url":null,"abstract":"Biological compounds are known to have infrared spectra indicative of specific functional groups. There is a strong interest in the use of passive means to detect airborne biological particles, such as spores and cells, which may act as biological weapons. At the sizes of interest, the infrared spectra of bacterial particles result from a combination of geometric (πdparticle > λ) and Mie (πdparticle ∼ λ) scattering processes, whereas the infrared spectrum of atmospheric particles falls into the Rayleigh limit (πdparticle ≪ λ). In this article we report on laboratory measurements of the infrared spectra of aerosolized Bacillus subtilis (BG) spores in air under controlled measurement conditions. Transmission measurements show an IR spectrum of the spores with features comparable to the condensed phase spectrum superimposed on a background of Mie scattering. Preliminary measurements indicate a peak extinction coefficient of approximately 1.6 × 10−8 cm2 per spore at 9.65 μm. These results are discussed in terms of their implication for passive and active infrared detection and identification of bio-aerosols. © 1999 John Wiley & Sons, Inc. Field Analyt Chem Technol 3: 274–282, 1999","PeriodicalId":12132,"journal":{"name":"Field Analytical Chemistry and Technology","volume":"21 1","pages":"274-282"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77681904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Rapid Toxicological Test Method with Luminous Bacteria for Laboratory - and On-Site Assessment of Wastes and Contaminated Soils","authors":"A. Götzl, H. Malissa, W. Riepe","doi":"10.1002/(SICI)1520-6521(1999)3:6<329::AID-FACT2>3.0.CO;2-Z","DOIUrl":"https://doi.org/10.1002/(SICI)1520-6521(1999)3:6<329::AID-FACT2>3.0.CO;2-Z","url":null,"abstract":"Comparison between a standard toxicological test with luminous bacteria based on DIN 38 412 L 341, 2 and a rapid test yield similar results. However, the standard deviation of the rapid test was lower than that of the standard test. Costs for material and instruments are low; the test is easy to handle and can be used on site. By appropriate choice of the dilution steps and proper timing by intercalating the individual sets of assays, the overall time required to obtain results can be shortened considerably compared to the standard test. In combination with a recently developed method for aqueous extraction this allows assessment of the risk in contaminated soil on site within 30–45 min. © 1999 John Wiley & Sons, Inc. Field Analyt Chem Technol 3: 329–337, 1999","PeriodicalId":12132,"journal":{"name":"Field Analytical Chemistry and Technology","volume":"6 1","pages":"329-337"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84731070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}