Unique system for studying flame spectrometric processes

Hieftje, Gary M.; Malmstadt, H. V.

doi:10.1021/ac60268a024

Cited by 143 publications

(65 citation statements)

References 12 publications

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“…Microdroplets and microparticles find use in many diverse scientific applications including investigation of solute atomization in flames for analytical spectroscopic analyses (Hieftje and Malmstadt 1968;Seymour and Boss 1983;Childers and Hieftje 1986), spray combustion and fuel injection (Sangiovanni and Labowsky 1982), agricultural spraying drift and deposition (Threadgill et al 1974), evaporation (Yang et al 1997) and other physical properties related to weather (Magarvey and Taylor 1956), and for assessing performance of particulate control devices and the effects of particulate air pollutants (Berglund and Liu 1973). More recently, aerosols have been tailored for use in drug delivery (Jain et al 1998;Hauschild et al 2005), Raman spectroscopy of levitated droplets (Trunk et al 1994), maskless lithography for microelectromechanical system (MEMS) fabrication (Wang et al 2004), and as particle standards containing trace levels of molecules for ion mobility spectroscopy (Fletcher et al 2008) and trace levels of elements for X--ray fluorescence spectrometry and laser ablation inductively coupled plasma mass spectrometry (Fittschen et al 2006;Fittschen et al 2008).…”

Section: Historic and Current Methods For Producing Microparticlesmentioning

confidence: 99%

“…When mechanical disturbances are generated at a constant frequency and with sufficient amplitude on a liquid jet moving at a constant velocity, the jet will break up into droplets of equal size (Berglund and Liu 1973). These periodic vibrations originated from devices such as a speaker (Magarvey and Taylor 1956;Stricker and Sofer 1991), motor--driven plunger (Magarvey and Taylor 1956), magnetostrictive transducer (Sweet 1965;Sangiovanni and Labowsky 1982), or, most commonly, a piezoelectric transducer (Hieftje and Malmstadt 1968;Stemme and Larsson 1973;Threadgill et al 1974;Buehner et al 1977;Seymour and Boss 1983;Maehara et al 1984;Childers and Hieftje 1986;Switzer 1991;Warnica et al 1991;Trunk et al 1994;Yang et al 1997). These early studies all used custom--built aerosol generation systems that were unique and elaborate, requiring considerable time and effort to construct and patience and skill to operate.…”

Section: Historic and Current Methods For Producing Microparticlesmentioning

confidence: 99%

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Statistical Data Analyses of Trace Chemical, Biochemical, and Physical Analytical Signatures

Udey

2013

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Analytical and bioanalytical chemistry measurement results are most meaningful when interpreted using rigorous statistical treatments of the data. The same data set may provide many dimensions of information depending on the questions asked through the applied statistical methods. Three principal projects illustrated the wealth of information gained through the application of statistical data analyses to diverse problems.Firstly, novel aerosol test particles containing DNA barcodes were developed for the accurate assessment of aerosol transport and fate in populated locations. Aerosols are central to human and environmental health, and understanding the properties of these aerosols that are pervasive in our lives is essential. Test particles composed of FDA--approved saccharide food additives were generated using both a modified inkjet printer and a commercial spray dryer.Univariate statistical methods were used to evaluate generated particle size--distributions during production optimization. Non--coding DNA templates were incorporated into the particles as unique particle identifiers, which yielded customized test particles detectable using highly specific quantitative real--time polymerase chain reaction (QRT--PCR) assays. These safe, customizable, and specifically detected aerosol test particles will provide vital experimental feedback for evaluating aerosol dispersion and transport models. The project culminated with a successful demonstration of the aerosol test particles in an atmospheric release test.Secondly, an original method for non--invasively analyzing the chemical profiles of latent fingerprint residues was developed in order to gain a new level of information from the most common type of forensic evidence. Passive solid--phase microextraction (SPME) headspace sampling collects both endogenous and exogenous volatile and semi--volatile compounds contained in the fingerprint residue while preserving the fingerprint for traditional analyses.The information--rich chemical profiles obtained from gas chromatography--mass spectrometry (GC--MS) analyses of the SPME samples were used to quantitatively compare fingerprint compounds both between subjects and over a time course of 30 days using multivariate statistical analyses.Finally, endogenous metabolite profiles of cancer cells treated with anti--cancer agents were analyzed using gas chromatography--and high performance liquid chromatography--mass spectrometry (GC--MS and HPLC--MS), and the resulting complex data sets were interrogated using univariate and multivariate statistical analyses (e.g. ANOVA, PCA, PLS--DA, OPLS--DA).Possible modes of cytotoxicity of cisplatin and taxol, two commonly used cancer therapeutics, in breast and lung cancer cells were elucidated using statistical methods for data reduction in order to focus on the cellular biochemical processes most affected by drug treatment.Understanding how successful therapeutics interact with cells leads to design of novel anti--cancer agents that are more targeted and effective, minimizing dose-...

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Section: Historic and Current Methods For Producing Microparticlesmentioning

confidence: 99%

Section: Historic and Current Methods For Producing Microparticlesmentioning

confidence: 99%

Statistical Data Analyses of Trace Chemical, Biochemical, and Physical Analytical Signatures

Udey

2013

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“…Unfortunately, a wide range of droplet sizes is produced and droplets travel an erratic path to and within the flame or plasma, making a detailed study of the events occurring to a single droplet almost impossible. To circumvent these difficulties, a device was developed (18,19) which enables individual droplets to be sent along a prescribed, reproducible trajectory in a flame. The photograph of Figure 6 shows this device in operation.…”

Section: Methods Based On Detection Of Charged Speciesmentioning

confidence: 99%

Approaching the limit in atomic spectrochemical analysis

Hieftje¹

1982

J. Chem. Educ.

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to the paper by Alkemade (1). Methods Based on Detection of Charged SpeciesAmong the most sensitive of the techniques used for monitoring atoms are those which rely upon ionization. Included among such techniques are resonance ionization spectroscopy, commonly abbreviated RIS (2, 3) and laser-enhanced ionization (LEI), which employs the so-called opto-galvanic effect or OGE (4). Because these detection methods are discussed in detail in other articles in this series, they will be considered only briefly here. The interested reader is referred to the papers by Hurst and Travis, respectively.The principles involved in RIS and LEI are easily understood with the aid of Figure 1. In Figure 1 ( See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles.

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“…The authors have for some time been active in the study of fundamental atom formation processes in flames (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). In these studies, a droplet generator is employed to produce equally sized spherical droplets of sample solution and to introduce those droplets into an analytical flame with reproducible, isochronal spacing.…”

Section: '4mmentioning

confidence: 99%

“…With this device, spatial and temporal separation of the individual atom formation processes occurs as a single droplet travels through a flame or plasma. Observation of these processes has then enabled detailed studies to be made on the desolvation of droplets in a flame (1,3,4), vaporization of the resulting solute particles (5,8,10,12), ionization of atoms (12), diffusion of the atoms (8,10), or the velocities of the flame or droplets themselves (6,9,11). Because others have expressed interest in these studies, and in pursuing similar ones, the authors have received numerous requests for circuit and mechanical diagrams of the droplet generator.…”

Section: '4mmentioning

confidence: 99%