University of North Florida
Browse the Citations
-OR-

Contact Info

Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

View Stuart Chalk's profile on LinkedIn

Nitro compounds

  • Molecular Formula: -NO2
  • CAS Registry Number: NA

@ ChemSpider@ NIST@ PubChem

Citations 8

"A Novel Flow-through Disk-based Solid-phase Extraction Diffuse Reflectance Optrode. Application To Preconcentration And Determination Of Trace Levels Of Nitrite"
Analyst 2001 Volume 126, Issue 10 Pages 1740-1746
Manuel Miró, Wolfgang Frenzel, José Manuel Estela and Víctor Cerdà

Abstract: A novel, versatile and sensitive flow-through optical fiber diffuse reflectance sensor to implement disk-based solid-phase extraction in a flow injection analysis (FIA) system is presented. Nitrite optosensing at trace levels is chosen as a model of chemistry to demonstrate its applicability. The methodology is based on on-line nitrite derivatization with Shinn reagent to form a moderately polar azo dye, whose pre-concentration oil to octadecyl covalently bonded silica gel particles tightly bound to an inert matrix (C-18 disk) is continuously monitored using a plug-in diode-array spectrophotometer. After the analytical signal has been recorded, fast sensor regeneration is achieved with a methanolic eluent, rendering the system ready for the next extraction. Selection of the solid disk support and the suitable flow-through cell configuration to reduce back-pressure effects are discussed in detail. By matching the illumination and retention zones, concentrations of nitrite as low as 1 ng mL-1 are easily determined using 2.5 mL of sample. A detection limit (3s (blank)) of 0.1 ng mL-1 of nitrite, repeatability and reproducibility better than 3.2%, an analytical throughput of 11 h-1 and an enrichment factor of 140 are the figures of merit of the proposed optrode. The utility of the flow-through optosensing system, wherein minimization of additive matrix interferences is feasible, was testified by the satisfactory results obtained in its application to tap, ground, harbor and aquarium water samples.
Ground Estuarine Water Water Sensor Spectrophotometry Optrode C18 Preconcentration Optimization Interferences

"Automated Mercury Film Electrode For Flow Injection Analysis And High Performance Liquid Chromatography Detection"
Anal. Chem. 1986 Volume 58, Issue 7 Pages 1578-1580
Hari Gunasingham, B. T. Tay, and K. P. Ang

Abstract: Microprocessor control was used in conjunction with a mercury-film wall-jet electrode to enable the reproducible control of formation of a fresh film surface, stripping and analysis. The application of the cited electrode for reductive detection in flow injection analysis and HPLC was studied. The mean coefficient of variation for the HPLC determination of nitro- and quinone compounds with this electrode as detector was 3% for injections in the range of 3.2 to 40 µg of analyte.
Electrode Polarography

"Trace Analysis For Explosives And Related Compounds Via High Performance Liquid Chromatography - Photolysis - Electrochemical Detection"
J. Forensic Sci. 1984 Volume 29, Issue 2 Pages 449-463
Krull IS, Ding X-D, Selavka C, Bratin K, Forcier G

Abstract: The cited methods (apparatus illustrated) have been applied in the analysis of standard explosives (e.g., 2,4,6-trinitrotoluene, dinitrotoluene and N-methyl-2,4,6,N-tetranitroaniline and other organic nitro-compounds) by using single- or dual-electrode detection. The responses of the dual-electrode detector were found to be a function of applied working potentials. The dual-electrode technique, which showed greater sensitivity than the single-electrode method, was applicable in the analysis of explosives, drugs, nitrate ester compounds, nitro-aromatics, nitro-PAH and similar such derivatives. Calibration graphs and rectilinearities of detector response for various nitro-compounds are given. Flow injection analysis - photolysis - electrochemical detection and HPLC - photolysis - electrochemical detection may be of value in organic or inorganic trace analysis.
HPLC Electrode Photochemistry Post-column derivatization

"Cyclic Voltammetry Of Some Quinones And Nitroaromatic Compounds Using A Mercury Film Wall-jet Detector And Flow Injection Analysis"
J. Singapore Natl. Acad. Sci. 1987 Volume 16, Issue 1 Pages 80-86
Ang, K. P.; Gunasingham, H.; Tay, B. T. (SFS)

Abstract: A technique combining flow injection analysis and cyclic voltammetry (CV) to study electrochemical reactions is described. The technique was used to study the redox behavior of a number of nitro and quinone compounds at a bare glassy carbon electrode (GCE) and a preplated Hg film electrode (MFE). The MFE can be automatically renewed under computer control, thus minimizing surface contamination. It also offers a number of benefits over the bare GCE which include more well-defined CV curves, more reversible behavior, and a wider cathodic range. The CV of 1-nitroanthraquinone using this equipment is described for the first time. (SFS)
Voltammetry Electrode Electrode

"Electrochemical Detection In HPLC. Post-column, Online, Continuous Photolytic Derivatizations For Improved Detection In HPLC - Hu - EC"
LC-GC 1984 Volume 2, Issue 3 Pages 214-221
Krull, I.S.;Ding, X.D.;Selavka, C.M.;Nelson, R.

Abstract: Online, continuous, post-column irradiation provides a useful and practical approach for derivatization in HPLC with electrochemical detection and flow injection analysis. Over-all specificity is improved by the use of a narrower-wavelength irradiation source, e.g., a laser. The resulting selective excitation allows detection of a single analyte in the presence of many other compounds. The instrumental arrangement and system optimization are discussed with particular emphasis on the type and design of the PTFE tubing used to convey HPLC mobile phases around the irradiation finger and to transfer derivative species to the detector. Detection limits of <50 ppb for most compounds have been achieved. Consideration is also given to single and dual electrochemical detection of the derivative species, determination of analytes appropriate for this approach, and determination of organic nitro- and phosphorothioate compounds.
HPLC Electrode Photochemistry Optimization Post-column derivatization

"Application Of FIA Techniques To Food Analysis"
Lebensm. Wiss. Technol. 1989 Volume 22, Issue 5 Pages 254-263
Lemieux, L.;Puchades, R.;Simard, R.E.

Abstract: A review is presented with 113 references. The application of flow injection analysis to the determination of sugars, nitrogenous compounds, heavy metals, halogen-containing ions and other minor components is discussed.
Food Review

"Waste Water Quality Monitoring"
Trends Anal. Chem. 1997 Volume 16, Issue 7 Pages 419-424
Olivier Thomas*, Frederic Th&eacute;raulaz, Victor Cerd&agrave;, Daniel Constant, Philippe Quevauviller

Abstract: A sequential-injected analysis (SIA) system equipped with two spectrophotometric detectors is described for waste water quality monitoring. The system is portable and gives rapid results for global pollution parameters such as COD, dissolved organic C and total suspended solids and the determination of specific compounds such as nitrate and anionic surfactants using a direct UV method, SIA methods were devised for non-absorbent species such as NH3, organic nitrogen, orthophosphates and organic P.
Waste Spectrophotometry Portable Sequential injection

"Fluorescent Derivatization Of Nitrite Ions With 2,3-Diaminonaphthalene Utilizing A PH Gradient In A Y-shaped Microchannel"
Anal. Sci. 2001 Volume 17, Issue 4 Pages 535-538
Tamao Odake, Mari Tabuchi, Takanori Sato, Hironori Susaki And Takashi Korenaga

Abstract: The on-chip derivatization of nitrite ions with 2,3-diaminonaphthalene (DAN) utilizing a pH gradient formed in a Y-shaped microchannel was investigated. Nitrite ions react with DAN at low pH, and strongly fluoresced at high pH. Therefore, a reaction at low pH followed by the addition of a strong alkaline solution is the usual procedure in a batch scheme. However, a strong alkaline solution, like an NaOH aqueous solution, erodes the wall of the microchannels in substrates made of glass or polymers, and has not been considered suitable for use in microchannels. We first investigated the derivatization reaction and fluorescent properties of nitrite ions with DAN. We found that the on-chip fluorescent derivatization reaction and detection without the addition of an alkaline solution is possible by controlling the pH values of the nitrite solution and the DAN solution to form a suitable pH gradient by utilizing a buffering effect of triethanolamine solution, which is used as an NO2 gas-absorption medium. These results have suggested the feasibility of novel reaction schemes which can provide the desired products due to a controlled pH gradient in the microchannels, as well as the possibility of an on-site monitoring microchip device for ambient NO2.
Fluorescence Microfluidic Optimization Method comparison