A New Spectrophotometric Method with Di-2-Pyridyl Ketone Benzoylhydrazone for Determination of Nickel(II)

Terra, Lúcia Helena; Encarnación, Maria; Suárez-Iha, V.

doi:10.1080/00387019708006687

Cited by 16 publications

(3 citation statements)

References 13 publications

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“…The results obtained are shown in Table 2, in the form of maximum concentration ratio accepted with a variation in the absorbance lower than 5%. As expected, several cations interfered at similar or even lower molar concentration than the copper concentration, especially those previously reported to form coloured complexes with dPKBH [13,14,15,16,17,18,19,20,21]. Although in many real samples most of the interfering species appear at lower concentration than copper, we studied the use of masking agents to avoid the potential interferences caused by these cations.…”

Section: Study Of Interferencesmentioning

confidence: 76%

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A simple and very sensitive spectrophotometric method for the direct determination of copper ions

2002

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A sensitive spectrophotometric method for the direct determination of copper in aqueous samples without a preconcentration step has been developed. It is based on the formation of a yellow complex with the chromogenic reagent di-2-pyridyl ketone benzoylhydrazone (dPKBH) in an alkaline medium. The complex stoichiometry was 1:2 (Cu:dPKBH) and presents maximum absorbance at 370 nm. The influence of chemical variables affecting the behaviour of the system such as pH, concentration of dPKBH, buffer solution and ethanol, order of addition of the reagents and stability of the complex, were evaluated. The molar absorptivity (epsilon) was 3.92x10(4) L mol(-1) cm(-1), and Beer's law was obeyed up to 3 mg L(-1) of copper. The relative standard deviation was 0.46% (n=11) for a sample containing 1 mg L(-1) Cu(II). The limit of detection was 2.5 micro g L(-1) and was therefore more sensitive than the direct methods reported previously. Finally, the method was successfully validated by analysing several real samples with different matrices, such as tap water, natural water or copper alloys, with an average relative error of 2.46%.

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Section: Study Of Interferencesmentioning

confidence: 76%

“…dPKBH has been previously described as a bidentate or tridentate ligand for several heavy metals [12]. Besides this, it has been applied to the spectrophotometric determination of iron [13,14,15], palladium [16], cobalt [17,18,19] and nickel [20,21].…”

Section: Introductionmentioning

confidence: 99%

A simple and very sensitive spectrophotometric method for the direct determination of copper ions

2002

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“…[12][13][14][15][16][17] The aim of the present study was to develop a method for Zn(II) determination, with no difficulty like those found in the dithizone method. Several hydrazones [18][19][20][21][22][23][24][25][26][27][28][29] find application in analytical chemistry because they act as very favorable multidentade ligands for different metal cations, mainly from the transition or pos-transition groups.…”

Section: Introductionmentioning

confidence: 99%

Spectrophotometric Flow Injection Methods for Zinc Determination in Pharmaceutical and Biological Samples

Gaubeur

Ávila-Terra

Masini³

et al. 2007

ANAL. SCI.

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Zinc ions form a yellow complex with di-2-pyridyl ketone salicyloylhydrazone (DPKSH). This complex showed maximum absorption at 376 nm, and it was used to develop spectrophotometric flow injection methods for Zn(II) determination in different samples. Two types of flow systems were proposed. In the first system, a linear analytical curve was obtained in a concentration range from 0.217 to 4.60 mg L(-1) Zn(II), with a detection limit of 48.8 microg L(-1). In the second system, a minicolumn packed with an anion exchanger resin was used to concentrate Zn(II) as a chlorocomplex, and a linear analytical curve within a concentration range from 0.0824 to 2.06 mg L(-1) Zn(II) was obtained, having a detection limit of 13.9 microg L(-1). The developed methods were applied to biological and pharmaceutical samples, and a great compliance was observed by comparing the results with ones obtained by an atomic absorption technique.

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Cytotoxic iron chelators: characterization of the structure, solution chemistry and redox activity of ligands and iron complexes of the di-2-pyridyl ketone isonicotinoyl hydrazone (HPKIH) analogues

et al. 2003

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Di-2-pyridyl ketone isonicotinoyl hydrazone (HPKIH) and a range of its analogues comprise a series of monobasic acids that are capable of binding iron (Fe) as tridentate ( N, N, O) ligands. Recently, we have shown that these chelators are highly cytotoxic, but show selective activity against cancer cells. Particularly interesting was the fact that cytotoxicity of theHPKIH analogues is maintained even after complexation with Fe. To understand the potent anti-tumor activity of these compounds, we have fully characterized their chemical properties. This included examination of the solution chemistry and X-ray crystal structures of both the ligands and Fe complexes from this class and the ability of these complexes to mediate redox reactions. Potentiometric titrations demonstrated that all chelators are present predominantly in their charge-neutral form at physiological pH (7.4), allowing access across biological membranes. Keto-enol tautomerism of the ligands was identified, with the tautomers exhibiting distinctly different protonation constants. Interestingly, the chelators form low-spin (diamagnetic) divalent Fe complexes in solution. The chelators form distorted octahedral complexes with Fe(II), with two tridentate ligands arranged in a meridional fashion. Electrochemistry of the Fe complexes in both aqueous and non-aqueous solutions revealed that the complexes are oxidized to their ferric form at relatively high potentials, but this oxidation is coupled to a rapid reaction with water to form a hydrated (carbinolamine) derivative, leading to irreversible electrochemistry. The Fe complexes of theHPKIH analogues caused marked DNA degradation in the presence of hydrogen peroxide. This observation confirms that Fe complexes from theHPKIH series mediate Fenton chemistry and do not repel DNA. Collectively, studies on the solution chemistry and structure of theseHPKIH analogues indicate that they can bind cellular Fe and enhance its redox activity, resulting in oxidative damage to vital biomolecules.

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A New Spectrophotometric Method with Di-2-Pyridyl Ketone Benzoylhydrazone for Determination of Nickel(II)

Cited by 16 publications

References 13 publications

A simple and very sensitive spectrophotometric method for the direct determination of copper ions

A simple and very sensitive spectrophotometric method for the direct determination of copper ions

Spectrophotometric Flow Injection Methods for Zinc Determination in Pharmaceutical and Biological Samples

Cytotoxic iron chelators: characterization of the structure, solution chemistry and redox activity of ligands and iron complexes of the di-2-pyridyl ketone isonicotinoyl hydrazone (HPKIH) analogues

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