University of North Florida
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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

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Endothall sodium

  • IUPAC Name: disodium;7-oxabicyclo[2.2.1]heptane-2,3-dicarboxylate
  • Molecular Formula: C8H10O5
  • CAS Registry Number: 145-73-3
  • InChI: InChI=1S/C8H10O5.2Na/c9-7(10)5-3-1-2-4(13-3)6(5)8(11)12;;/h3-6H,1-2H2,(H,9,10)(H,11,12);;/q;2*+1/p-2
  • InChI Key: XRHVZWWRFMCBAZ-UHFFFAOYSA-L

@ ChemSpider@ NIST@ PubChem

Citations 4

"Regenerable Immunobiosensor For The Chemiluminescent Flow Injection Analysis Of The Herbicide 2,4-D"
Talanta 2000 Volume 51, Issue 2 Pages 395-401
Christophe A. Marquette and Loïc J. Blum

Abstract: A semi-automated chemiluminescent competitive immunosensor for the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) is presented. Anti-2,4-D polyclonal antibodies are directly labelled with horseradish peroxidase allowing a p-iodophenol enhanced chemiluminescent detection. Using antigen immobilized on UltraBind type pre-activated membranes, the 2,4-D immunosensor exhibits low non-specific/specific binding ratio (maximum ratio: 5%) of the labelled antibodies. The quantification of free 2,4-D in water is performed by co-injecting the sample and the labelled antibodies in the flow system, incubating this solution with the antigen immobilized membrane and measuring the amount of specifically bound labelled antibodies. Such an analytical system enables the detection of 4 µg L-1 of free antigen in 20 min, and the 2,4-D detection is possible in the range 4 µg L-1 - 160 mg L-1. The immunosensor can be regenerated by simply flowing a chaotropic solution (0.1 M HCl, 0.1 M NaCl, 0.1 M glycine) in the system. This regeneration ability enables the achievement of more than 30 measurement cycles of free 2,4-D with the same antigen immobilized membrane with a good reproducibility (RSD = 12.5%).
Sensor Chemiluminescence Optical fiber

"Determination Of Paraquat By Flow Injection Spectrophotometry"
Anal. Chim. Acta 1993 Volume 284, Issue 2 Pages 275-279
Archana Jain, Krishna K. Verma and Alan Townshend*

Abstract: The cited method is based on the reduction of paraquat (I) to a blue radical cation by dehydroascorbic acid (produced by oxidizing ascorbic acid with potassium iodate). Samples (75 µL) were injected into a stream (1.1 ml/min) of water which merged with streams of 1 M NaOH and of 15 mM ascorbic acid containing 0.5 mM potassium iodate and 0.1% EDTA (0.3 and 0.6 ml/min, respectively) which had been pre-mixed in a 50 cm mixing coil. The merged streams then passed through a reaction coil (75 cm x 0.5 mm i.d.) maintained at 60°C, to a spectrophotometer where the absorbance was measured at 600 nm. The calibration graph was linear from 0.1-100 µg/ml of I and the detection limit was 20 ng/ml; the RSD (n = 6) were 1-2.5% (for 0.1-60 µg/ml of I). A large number of tested compounds (anions, metal ions and other pesticides) did not interfere; interference by diquat was masked with NaOH. The method was applied to potable water.
Water Water Spectrophotometry Heated reaction Interferences Linear dynamic range

"Amperometric Immunosensor For The Detection Of 2,4-dichlorophenoxyacetic Acid (2,4-D) In Water"
Anal. Lett. 1997 Volume 30, Issue 3 Pages 515-525
M. Wilmer; D. Trau; R. Renneberg; F. Spener

Abstract: An amperometric immunosensor for the determination of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) in water has been developed using sequential injection analysis techniques. The system is based on a rapid competitive enzyme immunoassay employing an alkaline phosphatase-labeled monoclonal antibody directed against the herbicide and an immunoreactor with 2,4-D immobilized via bovine serum albumin either to Eupergit in a column or directly to the surface of a glass capillary. The detection limit of the immunosensor at 0.1 µg 2,4-D/L without enrichment of the analyte makes automatic measurements of 2,4-D in drinking and groundwater feasible.
Water Ground Amperometry Sequential injection

"Development Of An Amperometric Flow Injection Immunoanalysis System For The Determination Of The Herbicide 2,4-dichlorophenoxyacetic Acid In Water"
Biosens. Bioelectron. 1997 Volume 12, Issue 6 Pages 499-510
Dieter Trau, Thomas Theuerl, Marianne Wilmer, Markus Meusel*, and Friedrich Spener

Abstract: An amperometric flow injection immunoanalysis (FIIA) system based on an immunoreactor with immobilized biocomponents on a silica surface has been developed for the determination of the herbicide 2,4- dichlorophenoxyacetic acid (2,4-D). In the antigen coating mode the hapten was immobilized and monoclonal primary antibody against 2,4-D together with alkaline phosphatase (AP)-labelled secondary antibody were used as sensing elements in a titration assay. In the antibody coating mode a biotinylated monoclonal antibody was immobilized on the surface of the immunoreactor and a 2,4-D-AP-conjugate was used for detection. For electrochemical measurements p-aminophenol enzymatically generated from p-aminophenyl phosphate was oxidized at a carbon working electrode at +150 mV versus Ag/AgCl. The system enabled the determination of 2,4-D in drinking water samples in the range from 0.2 to 70 µg/l. The whole system was computer controlled with a measuring time of 12 min for one determination.
Water Immunoassay Amperometry Electrode Electrode Titrations Computer