Journal of research of the National Bureau of Standards最新文献_第7页

ICP Trace Element Analyses from Fusion Dissolution 熔融溶解ICP微量元素分析

Journal of research of the National Bureau of Standards Pub Date : 1988-05-01 DOI: 10.6028/jres.093.117

D. Brown, G. Légère, P. Burgener

引用次数: 0

Flow Injection-Inductively Coupled Plasma Spectrometry: A New Strategy for Ultratrace Analysis 流动注射-电感耦合等离子体光谱法:超痕量分析的新策略

Journal of research of the National Bureau of Standards Pub Date : 1988-05-01 DOI: 10.6028/jres.093.119

C. Mcleod, Y. Zhang, I. Cook, A. Cox, A. R. Date, Y. Y. Cheung

{"title":"Flow Injection-Inductively Coupled Plasma Spectrometry: A New Strategy for Ultratrace Analysis","authors":"C. Mcleod, Y. Zhang, I. Cook, A. Cox, A. R. Date, Y. Y. Cheung","doi":"10.6028/jres.093.119","DOIUrl":"https://doi.org/10.6028/jres.093.119","url":null,"abstract":"[I] Snelleman, W., Rains, T. C., Yee, K. W., Cook, H. D., and Menis, O., Anal. Chem. 42, 394 (1970). [2] Epstein, M. S., and O'Haver, T. C., Spectrochim. Acta 30B, 135 (1975). [3] Epstein, M. S., and Winefordner, J. D., Prog. Analyt. Atom. Spectrosc. 7, 67 (1984). [4] McLeod, C. W., Cook, 1. G., Worsfold, P. J., Davies, J. E., and Queny, J., Spectrochim. Acta 40B, 57 (1985). [5] Cook, 1. G., McLeod, C. W., and Worsfold, P. J., Anal. Proc. 23, 5 (1986). [6] Deardorff, E. R., Private Communication, National Bureau of Standards, March 1981. [7] Smith, M. V., and Burke, R. W., Private Communication, National Bureau of Standards, August 1987. [8] Wittman, A., and Schuster, L., Spectrochim. Acta 42B, 413 (1987). [2,3]. In the experiment relatively large volumes of sample are passed through a microcolumn in the flow injection (FI) manifold and retained analytes are subsequently eluted by injection of a small volume of eluent. Activated alumina offers a novel route for analyte preconcentration since it can function both as an anion and a cation exchanger depending upon solution pH. Under acidic and basic conditions alumina exhibits a high affinity for oxyanions and cations, respectively:","PeriodicalId":17082,"journal":{"name":"Journal of research of the National Bureau of Standards","volume":"93 1","pages":"462 - 464"},"PeriodicalIF":0.0,"publicationDate":"1988-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71363180","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}

引用次数: 8

Process Analytical Chemistry 过程分析化学

Journal of research of the National Bureau of Standards Pub Date : 1988-05-01 DOI: 10.6028/jres.093.018

B. Kowalski

引用次数: 38

Accuracy in the Determination of Chlorinated Dibenzo-p-Dioxins and Dibenzofurans in Environmental Samples 环境样品中氯代二苯并对二恶英和二苯并呋喃测定的准确性

Journal of research of the National Bureau of Standards Pub Date : 1988-05-01 DOI: 10.6028/jres.093.030

L. Lamparski, T. Nestrick

{"title":"Accuracy in the Determination of Chlorinated Dibenzo-p-Dioxins and Dibenzofurans in Environmental Samples","authors":"L. Lamparski, T. Nestrick","doi":"10.6028/jres.093.030","DOIUrl":"https://doi.org/10.6028/jres.093.030","url":null,"abstract":"The analytical chemist involved in industrial trace analysis is frequently confronted with many varied problems. Programs to produce acceptable data can be divided into two classes depending upon the level of quality assurance that is required. Frequently, unvalidated analytical procedures can be used to generate data for screening programs or process control. On the other hand, validated methods with rigorous quality assurance guidelines are absolutely necessary for work involving product specifications, industrial hygiene, or regulatory matters. When the analyst is asked to develop a trace analytical method, he must determine the end-use of the data. There are many parameters which must be factored into the analytical method. The analyst would like to build into the method the highest achievable sensitivity, accuracy, and reliability; and the customer wants the lowest cost and fastest analysis time possible. We can see then, from a practical viewpoint, the method development begins with a series of compromises. When implemented properly, these compromises can improve the overall quality of the method. The American Chemical Society has published \"Principles of Environmental Analysis\" [Anal. Chem. 55, 2210 (1983)] to aid in designing analytical measurements on environmental samples. The relationship between the number of samples necessary to obtain data within a defined acceptable error, and the standard deviation of the method, is shown by the equation:","PeriodicalId":17082,"journal":{"name":"Journal of research of the National Bureau of Standards","volume":"93 1","pages":"241 - 242"},"PeriodicalIF":0.0,"publicationDate":"1988-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71361858","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}

引用次数: 0

Ethyl Carbamate Analysis in Fermented Products: A Comparison of Measurements of Mass Spectrometry, Thermal Energy Analyser, and Hall Electrolytic Conductivity Detector 发酵产品中氨基甲酸乙酯的分析:质谱、热能分析仪和霍尔电导率检测器测量的比较

Journal of research of the National Bureau of Standards Pub Date : 1988-05-01 DOI: 10.6028/jres.093.033

M. Dennis, N. Howarth, R. Massey, D. J. Mcweeny, I. Parker, M. Scotter, J. Startin

引用次数: 2

Trace Analysis by Degrees: An Academic Perspective 学位痕量分析:学术视角

Journal of research of the National Bureau of Standards Pub Date : 1988-05-01 DOI: 10.6028/jres.093.014

G. Morrison

{"title":"Trace Analysis by Degrees: An Academic Perspective","authors":"G. Morrison","doi":"10.6028/jres.093.014","DOIUrl":"https://doi.org/10.6028/jres.093.014","url":null,"abstract":"The increasing awareness of the important role of very small amounts of chemical species in chemical, physical, and biological systems has greatly stimulated the refinement and extension of analyses at these levels. The analytical requirements imposed by the minute quantities and typically complex systems involved has led to the development of methodology and instrumentation so specialized as to warrant consideration as a distinct field of analytical chemistry-trace analysis. One of the aims of this symposium is to gain an accurate assessment of the current state of this field, and this paper is an attempt to present this status from an academic perspective. In order to discuss any specialty in analytical chemistry as carried on in colleges and universities, it is necessary to first review the current status of the whole discipline. It must be stated that the main missions of universities are teaching and research, and chemistry, one of the basic sciences, is an essential discipline in most colleges and universities. How does analytical chemistry fare in academe? A review of the American Chemical Society Directory of Graduate Research lists faculties, publications and theses in chemistry and other related disciplines at universities in the United States and Canada. A review of the 1985 edition, the latest available, reveals that of the 315 chemistry departments listed, 201 include analytical chemistry with 510 analytical faculty members. It is obvious that these departments cover a wide range of sizes, so that some of the smaller institutions are less structured. Of these 201 departments, 80 have at least three or more analytical chemistry faculty members. What becomes quite apparent from a review of the data is that while analytical chemistry is not formally included in every department, there are a significant number of strong analytical departments in the United States and Canada to advance the science adequately. In this environment we can now turn our attention to trace analysis. With regard to trace analysis research, two major approaches are evident: development of new techniques and methodology, and application to important problems. Because the field of trace analysis is so broad, I have chosen to limit my evaluation to trace element analysis, the area of my expertise. This specialty can be conveniently divided into three categories: bulk analysis, spatially resolved analysis, and speciation. In the area of applications, trace analytical research is being pursued by a good number of faculty to solve important biomedical, environmental, solid state materials, and geochemical problems. Among the techniques currently being employed for bulk trace analysis, electroanalytical, atomic spectroscopy, x-ray fluorescence, activation analysis, and mass spectrometry are the most advanced and most used. A review of bulk trace techniques over the past 40 years indicates continuous progress in each of these categories. See figure 1. Thus, each of these","PeriodicalId":17082,"journal":{"name":"Journal of research of the National Bureau of Standards","volume":"93 1","pages":"187 - 188"},"PeriodicalIF":0.0,"publicationDate":"1988-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71362083","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}

引用次数: 0

Annular Denuders and Filter Packs Designed to Measure Ambient Levels of Acidic and Basic Air Pollutants 设计用于测量环境中酸性和碱性空气污染物水平的环形剥光器和过滤器包

Journal of research of the National Bureau of Standards Pub Date : 1988-05-01 DOI: 10.6028/jres.093.046

R. Stevens

{"title":"Annular Denuders and Filter Packs Designed to Measure Ambient Levels of Acidic and Basic Air Pollutants","authors":"R. Stevens","doi":"10.6028/jres.093.046","DOIUrl":"https://doi.org/10.6028/jres.093.046","url":null,"abstract":"The GC-MS data files for three field samples were also analyzed [3]. The identities of the target compounds were determined by using both GC retention times and a combination of forward and reverse spectral matching techniques with stringent matching parameters. The identification of other compounds not on the target list was based on a Finnigan search technique. The application of the pattern recognition scheme to the transformed data for the target compounds resulted in 88% correct classification. The compound identification results were 85% accurate. There were 75 different nontarget compounds identified in 120 occurrences in the three samples. The classification results agreed very well for the two class I and class 2 spectra. However, a very large number of alkanes and alkenes were incorrectly classified as chlorocompounds. Further details of this study are given in references [2], [3], and [4]. Although the research described in this article has been funded by the U.S. Environmental Protection Agency under Cooperative Agreement CR-811617 with the University of Illinois at Chicago, it has not been subjected to Agency review. The mention of commercial products does not constitute endorsement or recommendation for use.","PeriodicalId":17082,"journal":{"name":"Journal of research of the National Bureau of Standards","volume":"93 1","pages":"283 - 284"},"PeriodicalIF":0.0,"publicationDate":"1988-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71362090","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}

引用次数: 0

Chemometrics and Standards 化学计量学与标准

Journal of research of the National Bureau of Standards Pub Date : 1988-05-01 DOI: 10.6028/jres.093.017

L. Currie

{"title":"Chemometrics and Standards","authors":"L. Currie","doi":"10.6028/jres.093.017","DOIUrl":"https://doi.org/10.6028/jres.093.017","url":null,"abstract":"Standards are central to the achievement and maintenance of accuracy in trace analysis. This fact is well-known and well-accepted in the international analytical chemical community, where \"standards\" are generally considered to be Standard Reference Materials (SRMs) or Certified Reference Materials (CRMs). The term, standards, however, is multivalued, as noted recently by a former Director of the National Bureau of Standards [1]. That is, even in our more conventional view of trace analysis, we must consider in addition to standard materials: standard procedures (protocols), standard data (reference data), standard units (SI), standard nomenclature, standard (certified) instruments, and standard tolerances (regulatory standards, specifications, norms) [2]. It is interesting, in light of these several types of \"standards\" which have some bearing oil accuracy in trace analysis, to consider the possible significance of standards in and for Chemometrics. To pursue this objective, we first must have a common understanding of the meaning of the term, chemometrics, and what significance it may have for accurate trace analysis. A concise definition is given by the subtitle of the volume which resulted from the first NATO Advanced Study Institute on Chemometrics, i.e., \"Mathematics and Statistics in Chemistry\" [3]. Implications for accuracy, especially accuracy in trace analysis, are immediately evident. That is, wherever mathematical or statistical operations contribute to the experimental design, data evaluation, assumption testing, or quality control for accurate chemical analysis, \"chemometric standards\" are at least implicitly relevant. The major part of this paper will be devoted to an explicit discussion of such chemometric standards, including case studies drawn from recent research at the National Bureau of Standards. The discussion will be placed in the framework of the Analytical System, or Chemical Measurement Process (CMP), for such a perspective makes it possible to consider logically a \"theory of analytical chemistry\"; and certainly chemometrics is a very important part of such a theory [4,5]. To set the stage, the next section will include a brief view of the current content of Chemometrics, together with a summary of its history and literature. This article will conclude with a glimpse at the future of chemometrics, with special emphasis on means to achieve increased accuracy in our chemical measurements and increased understanding of the external (physical, biological, geochemical) systems which provide the driving forces for analytical chemistry.","PeriodicalId":17082,"journal":{"name":"Journal of research of the National Bureau of Standards","volume":"93 1","pages":"193 - 205"},"PeriodicalIF":0.0,"publicationDate":"1988-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71362132","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}

引用次数: 3

Determination of 3-Quinuclidinyl Benzilate in Urine 尿中3-喹啉苄基苯甲酸酯的测定

Journal of research of the National Bureau of Standards Pub Date : 1988-05-01 DOI: 10.6028/jres.093.050

G. Byrd, L. Sniegoski, E. White

{"title":"Determination of 3-Quinuclidinyl Benzilate in Urine","authors":"G. Byrd, L. Sniegoski, E. White","doi":"10.6028/jres.093.050","DOIUrl":"https://doi.org/10.6028/jres.093.050","url":null,"abstract":"The compound 3-quinuclidinyl benzilate (BZ) is a potent muscarinic cholinergic antagonist that can produce incapacitation at very small doses [1,2]. As such it can be used as a powerful psychochemical warfare agent. In response to the scheduled destruction of U.S. military stockpiles of BZ and the increased potential for worker exposure, our laboratory has developed a specific confirmatory test for human exposure to BZ. The test determines the amount of the parent compound in the urine as well as the two major metabolites, quinuclidinol (Q) and benzilic acid (BA) which are formed by hydrolysis as shown in figure 1. Previous work in our laboratory demonstrated that BA and Q could be determined in urine at their target concentration of 5 ng/mL as based on a proposed acceptable exposure level. The work described here demonstrates the recovery of the parent compound from urine at its target level and the incorporation of this method into an overall test for exposure to BZ. Only a small percentage of unmetabolized BZ is expected to be found in the urine of exposed persons. Estimates based on the proposed acceptable exposure level require detection limits for BZ in urine of 0.5 ng/mL. Because of the complexity of the urine matrix and the variation of urine from one individual to the next, the measurement of BZ in urine at this level presents a challenging analytical problem. A method using solid phase extraction and isotope dilution GC/MS was developed to measure BZ in urine. In the procedure, a 20 mL urine sample is made basic and the BZ is removed by solid phase extraction onto a C1 g sample preparation column. The column is washed with water and a 40% acetonitrile solution and the BZ is eluted with methanol. The eluent is blown to dryness and reconstituted in a derivatizing agent to form the trimethylsilyl derivative for analysis by GC/MS. Measurements are performed using single ion monitoring for the fragment ion (C6 H5 )2COTMS' at m/z 255 and the analogous ion from the isotopically labeled internal standard (3-quinuclidinyl-' 8 O-benzilate-d 5) at m/z 260. We have been able to determine BZ in urine at concentrations less than 0.5 ng/mL. Figure 2 depicts an ion chromatogram showing detection of BZ as its TMS derivative at 0.5 ng/mL. This method was incorporated into the overall test for exposure to BZ which determines the concentration of BZ, BA, and Q in urine. The test was validated by looking at eight different urine samples which were divided into subsamples, some spiked with known concentrations of the analytes and others left blank. Of the 18 subsamples that were analyzed for BZ, BA, and Q, nine were spiked at or just below the target concentration level, five at approximately 10 times the target level, and four were blank. The subsamples spiked at 10 times the target level were to provide information for urine samples with concentration levels that would be expected in the event of an actual exposure. The blank urine samples provided informa","PeriodicalId":17082,"journal":{"name":"Journal of research of the National Bureau of Standards","volume":"93 1","pages":"293 - 295"},"PeriodicalIF":0.0,"publicationDate":"1988-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71362146","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}

引用次数: 5

Quantification of Toxic Chemicals in Selected Human Populations 特定人群中有毒化学物质的定量分析

Journal of research of the National Bureau of Standards Pub Date : 1988-05-01 DOI: 10.6028/jres.093.098

J. Holler, D. Patterson, S. Smith

{"title":"Quantification of Toxic Chemicals in Selected Human Populations","authors":"J. Holler, D. Patterson, S. Smith","doi":"10.6028/jres.093.098","DOIUrl":"https://doi.org/10.6028/jres.093.098","url":null,"abstract":"the pg/mL range with in-line preconcentration [5]. During the development of this method at NBS, the factors investigated included: composition of the eluents, interference due to impurities in the delivery liquid and the possible means of eliminating them with a laboratory-packed trap column, and a comparison of suppression efficiencies between two types of suppressors. This method was used for the determination of Mg\"2 and Ca\"2 in SRM 2694, Simulated Rainwater, with precisions and accuracies better than 2% relative [5]. The frontier for ion chromatography is transition metal analysis with ongoing research along many fronts. New resins are being introduced and are being coupled to exotic detectors. The era of \"hyphenated\" techniques is burgeoning with ion chromatography showing up as the front-end separation method of choice. Recent work at NBS has coupled ion chromatography with direct current plasma emission spectrometry for the determination of phosphorus in copper-based alloys [6]. Future challenges for ion chromatography will be to enhance further its capabilities through improved speed, sensitivity, and resolution. Speciation of metals as a function of oxidation state and complexation will be an important goal. Innovative resins and a new generation of detectors will have to be developed. Fundamental research into the retention mechanisms leading to the separation will be essential. In conclusion, ion chromatography has proven itself an invaluable tool to analytical chemistry. Its ultimate advantages will lie in its versatility and its capacity for ultra-trace analyses with minimal contamination and total automation.","PeriodicalId":17082,"journal":{"name":"Journal of research of the National Bureau of Standards","volume":"93 1","pages":"412 - 413"},"PeriodicalIF":0.0,"publicationDate":"1988-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71362367","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}

引用次数: 2