Micellar Colorimetric Determination of Dithizone Metal Chelates

Paradkar, Rajesh P.; Williams, R. R.

doi:10.1021/ac00089a024

Cited by 100 publications

(46 citation statements)

References 18 publications

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“…To quantify the presence of Zn 2+ in the purified MBP or MBP-ZmMT4 proteins, 0.2 to 0.26 mg of each protein, in triplicate, was incubated with 1 N HCl for 45 min at room temperature and centrifuged at 20,000g for 2 min. The release of Zn 2+ was quantitatively evaluated by DTZ (diphenylthiocarbazone) by following published protocols (Paradkar and Williams, 1994). For the Zn 2+ release by DEA/NO, 1 concentration of ZmMT4 and MBP (as negative control), in triplicate, was incubated at room temperature for 45 min in 0.05 M Tris-HCl (pH 7.5) with 3 mM DEA/NO or the same amount of water (negative control).…”

Section: Release Of Znmentioning

confidence: 99%

Hemoglobin Control of Cell Survival/Death Decision Regulates in Vitro Plant Embryogenesis

et al. 2014

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Programmed cell death (PCD) in multicellular organisms is a vital process in growth, development, and stress responses that contributes to the formation of tissues and organs. Although numerous studies have defined the molecular participants in apoptotic and PCD cascades, successful identification of early master regulators that target specific cells to live or die is limited. Using Zea mays somatic embryogenesis as a model system, we report that the expressions of two plant hemoglobin (Hb) genes (ZmHb1 and ZmHb2) regulate the cell survival/death decision that influences somatic embryogenesis through their cell-specific localization patterns. Suppression of either of the two ZmHbs is sufficient to induce PCD through a pathway initiated by elevated NO and Zn 2+ levels and mediated by production of reactive oxygen species. The effect of the death program on the fate of the developing embryos is dependent on the localization patterns of the two ZmHbs. During somatic embryogenesis, ZmHb2 transcripts are restricted to a few cells anchoring the embryos to the subtending embryogenic tissue, whereas ZmHb1 transcripts extend to several embryonic domains. Suppression of ZmHb2 induces PCD in the anchoring cells, allowing the embryos to develop further, whereas suppression of ZmHb1 results in massive PCD, leading to abortion. We conclude that regulation of the expression of these ZmHbs has the capability to determine the developmental fate of the embryogenic tissue during somatic embryogenesis through their effect on PCD. This unique regulation might have implications for development and differentiation in other species.

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Section: Release Of Znmentioning

confidence: 99%

Hemoglobin Control of Cell Survival/Death Decision Regulates in Vitro Plant Embryogenesis

et al. 2014

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“…Here, φ is the molar volume of the micelle (1.29 M -1 ), 7 and CTriton X-100 and CCMC are the total concentration of Triton X-100 and the critical micelle concentration of the surfactant (2.4 × 10 -4 M), 20 respectively. Using the above equilibrium constants, the mass balance of the extractant in the whole micellar solution can be written as:…”

Section: Data Treatmentmentioning

confidence: 99%

“…Many studies on the extraction of metals with water-insoluble chelating reagents using this useful medium have been reported, not only for applications in separation and preconcentration [6][7][8][9] but also for fundamental research on the equilibria and kinetics of the extraction. [10][11][12][13][14][15][16] The author has been interested in differences of extraction efficiencies in both equilibria and kinetics between micellar and conventional liquid-liquid systems and has studied to determine the effectiveness and possibility of the pseudophase system being applied for a practical separation/determination medium as to be an analogy of droplets of organic solvents.…”

mentioning

confidence: 99%

Unusually Slow Extraction Rate and Mechanism of Iron(III) with Trifluoroacetylacetone in Triton X-100 Micellar System. Part I. Extraction Routes

Inaba

2000

ANAL. SCI.

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Micellar and related biphasic solution systems have been used in many fields of chemistry instead of liquid-liquid systems, [1][2][3][4][5] because of the unique characteristics that the solutions can be handled safely and are environmentally-friendly while each system seems to have two phases without the use of toxic and/or flammable organic solvent. Many studies on the extraction of metals with water-insoluble chelating reagents using this useful medium have been reported, not only for applications in separation and preconcentration 6-9 but also for fundamental research on the equilibria and kinetics of the extraction. [10][11][12][13][14][15][16] The author has been interested in differences of extraction efficiencies in both equilibria and kinetics between micellar and conventional liquid-liquid systems and has studied to determine the effectiveness and possibility of the pseudophase system being applied for a practical separation/determination medium as to be an analogy of droplets of organic solvents. 17,18 During the kinetic study of the extraction of iron(III) with benzoylacetone (Hbza) and benzoyltrifluoroacetone (Hbfa) into Triton X-100 micelle, the extraction mechanism with the latter extractant was found to be somewhat different from that in a conventional non-polar organic solvent-water system such as hexane-water, although the whole extraction equilibria in the micellar system can be analyzed by a manner similar to that in the liquid-liquid system. 17 The ligands had no long alkyl chains and no additional salt was dissolved in the bulk aqueous phase during the study; thus the whole formation/extraction reaction in the system should be controlled by formation of the monocomplex in the bulk aqueous phase. All the overall reactions with Hbza were controlled only by the formation of the monocomplex in the bulk aqueous phase; however, the rate for Hbfa extraction was slower than that for the complex formation in the bulk aqueous phase as estimated from the partition constant of the extractant. The effect found in the Hbfa extraction system has been observed also in the other trifluoromethyl substituted β-diketone system. 19Such differences may affect the efficiencies of analysis i.e., separation factor or determination time, and thus, thorough considerations are necessary to utilize the medium for practical analytical processes.In the present study, the rate of formation/extraction of iron(III) with trifluoroacetylacetone in the Triton X-100 micellar system has been investigated and compared with the rate of complex formation measured separately in aqueous solutions in order to clarify the change of the extraction rate. The ligand is much simpler and more water soluble than Hbfa; thus the rate of complex formation in the aqueous phase can be measured easily and the difference in the mechanism of complex formation in these solutions can be discussed precisely. ExperimentalAll the reagents were of analytical grade and were used without purification. The trifluoroacetylacetone (1,1,1-trifluoro-2,4-pentaned...

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“…Absorption molecular spectroscopy (UV-V) methods were used for cadmium determination [6][7][8][9] . Spectrophotometric detection even is a widely used technique, because its simplicity, lower cost of instrumentation, and usually is precise and accurate.…”

Section: Introductionmentioning

confidence: 99%

“…Dithizone, the old and known reagent, is still used as chromogenic reagent for heavy metals determination, with the classical extraction of the analyte in organic medium. The use of this reagent in aqueous/surfactant medium has been reported 6 to prevent the use of chlorinate solvents. However, the reagent in this conditions is unstable to light exposure, so there is not evidence in the literature of its application in other analytical determinations.…”

Section: Introductionmentioning

confidence: 99%

Automated flow-injection method for cadmium determination with pre-concentration and reagent preparation on-line

Nezio¹,

Palomeque²,

Band³

2005

Quím. Nova

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Micellar Colorimetric Determination of Dithizone Metal Chelates

Cited by 100 publications

References 18 publications

Hemoglobin Control of Cell Survival/Death Decision Regulates in Vitro Plant Embryogenesis

Hemoglobin Control of Cell Survival/Death Decision Regulates in Vitro Plant Embryogenesis

Unusually Slow Extraction Rate and Mechanism of Iron(III) with Trifluoroacetylacetone in Triton X-100 Micellar System. Part I. Extraction Routes

Automated flow-injection method for cadmium determination with pre-concentration and reagent preparation on-line

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