Indian Journal of Chemistry

Sect. A: Inorganic, Bio-inorganic, Physical, Theoretical & Analytical


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VOLUME 44A

NUMBER 7

JULY 2005

 

CONTENTS

Papers

 

1333

 

 

Determination of potential energy function and transport properties of sulphur hexafluoride

 

 

 

Elaheh K Goharshadi*, Masoud Nahali & Mahmood Baherololoom

 

 

 

The potential energy function of sulphur hexafluoride has been determined via the inversion of reduced viscosity collision integrals at zero pressure and fitted to obtain an analytical potential form. This method reproduces, within experimental error, viscosity, self-diffusion coefficient, thermal conductivity, and isotopic thermal diffusion factor of sulphur hexafluoride over a wide temperature range.

 

 

1339

 

 

Calculation of the second virial coefficients of non-spherical molecules in binary mixtures

 

 

 

 

Fariba S Hashemi*, Ezat Keshavarzi &
Parvaneh Maleki

 

 

 

The second virial coefficients for simple molecular gases like CO2, CO, N2, O2  and their binary equimolar mixtures among themselves and with Ar have been calculated through revised analysis of the effect of long-range non-spherical terms in the intermolecular potential functions. The predicted values are in agreement with the experimental data.

 

 

1345

 

 

One pot acetalization of ketones with methanol over rare earth metal exchanged NaFAU-Y zeolites

 

 

 

 

 

Bejoy Thomas & S Sugunan*

 

 

 

Room temperature one pot acetalization of cyclohexanone, acetophenone and benzophenone with methanol over rare earth exchanged NAFAU-Y zeolites as catalysts is reported. The catalysts are poisoned by water and the reaction stops as soon as sufficient water is produced during the reaction to fully poison the catalyst. The activity of ketones follows the order: cyclohexanone> acetophenone> benzophenone, which is the reverse order of molecular size.

 

1355

 

 

Polyethylene glycol degradation by UV irradiation

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ishwar Das* & Sujeet Kumar Gupta

 

 

 

A drastic change in the morphology from spherulite to rhythmic pattern has been observed under polarized light microscope when polyethylene glycol is exposed to UV light. Changes are also observed in UV, IR and powder X-ray diffraction pattern of polyethylene glycol on exposure to UV light.

 

 

1359

 

 

Kinetic study of the addition reaction of carbon tetrachloride to 1-hexene initiated by chromium hexacarbonyl in the presence of UV light

 

 

 

 

 

A Harfoush

 

 

 

Addition reaction of CCl4 to the double bond of
1-hexene in the presence of Cr(CO)6 and light follows a free radical chain route in which the metal complex acts solely as an initiator. UV light is responsible for the initiation of the free radical chain process and for the formation of photocatalytic species, which are photolabile and responsible for the small amount of addition reaction product formed during the dark periods. Cr(CO)6 shows initiation efficiency comparable with organic peroxides, but other complexes like Mo(CO)6 and W(CO)6 are less efficient.

 

 

1365

 

 

Densities and viscosities of binary liquid systems of acetonitrile with aromatic ketones at 308.15 K

 

 

T Savitha Jyostna & N Satyanarayana*

 

 

 

The densities and viscosities for the binary
mixtures of acetonitrile + aromatic ketones (acetophenone, propiophenone, p-methylacetophenone and p-chloro-acetophenone) at 308.15 K are reported over the entire range of composition and used to calculate the excess molar volumes and deviations in viscosity.

 

 

1372

 

 

Spectroscopic studies on charge transfer complexes of 1, 4, 10 ,13–tetraoxa – 7, 16-diazacyclooctadecane with a series of electron acceptors

 

 

Akmal S Gaballa

 

 

 

The interaction of the mixed oxygen-nitrogen cyclic base 1, 4, 10, 13 – tetraoxa-7, 16 – diazacyclooctadecane with various π-acceptors, viz., picric acid, chloranilic acid and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone has been studied spectrophotometrically in CHCl3 and MeOH at 25°C. Spectral data indicate a strong interaction between the donor and acceptors associated with proton migration followed by intramolecular hydrogen bonding.

 

 

1378

 

 

Application of proton induced X-Ray emission (PIXE) in estimation of trace metals entrapped in silica matrix

 

 

P K Jal, M Sudarshan, A Saha, Sabita Patel &B K Mishra*

 

 

 

Proton induced X-ray emission technique is used for multielemental analysis of metal ions adsorbed on nanosilica surface. At pH 3.5, silica traps uranium selectively from a mixture of solutions of 13 different metal ions, viz., K(I), Ca(II), Fe(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Sr(II), Cd(II), Ba(II), Hg(II) and UO2(VI).

 

 

1383

 

 

Synthesis and characterization of a new phase of stannic arsenate ion exchanger and its use in TLC separations of metal ions

 

Syed Ashfaq Nabi* & Amjad M T Khan

 

 

 

A new phase of inorganic ion exchanger, stannic arsenate, has been synthesized by mixing 0.2 M solution of stannic chloride pentahydrate with 0.4 M sodium arsenate solution in the volume ratio 3:1 at pH 0.40.  The ion exchange capacity of the material for Ba2+ is found to be 2.73 meq/g of dry exchanger.

 

Notes

1388

 

 

Studies on B-site doped LaSrCoO4 mixed oxides towards CO and C3H8 oxidation

 

Laitao Luo*, Guangxin Shao & Zhanhui Duan

 

 

 

A series of LaSrCo0.9B′0.1O4 (B′= Mn, Fe, Ni, Cu) mixed oxides have been prepared by the polyacrylamide gel method and used successfully for CO and C3H8 oxidations. In comparison to the LaSrCoO4, the activity of LaSrCo0.9Ni0.1O4 for CO and C3H8 oxidation is higher, while the activity of Mn, Fe or Cu-doped catalysts is lower.

 

1392

 

 

KMnO4-Al2O3 as a highly efficient and mild catalyst for regeneration of carbonyl compounds from hydrazones in the solid state

 

 

 

G H Imanzadeh Karkaragh* & H Eskandari

 

 

 

 

 

 

 

 

1395

 

 

Development of electrochemical supercapacitors using underpotential deposition of thallium on silver

 

 

 

T C Girija & M V Sangaranarayanan*

 

 

 

Electrochemical supercapacitors have been designed using the underpotential deposition of thallium on silver. The specific capacitance is deduced as 3.45 ´ 102
Farads g-1 from cyclic voltammetric studies.

 

 

1398

 

 

QSAR studies on pyrrolo(2,1-d) (1,2,3,5)-tetrazinones, a new class of azolotetrazines

 

 

 

 

 

Girish Tripathi & J P Mishra*

 

 

 

 

 

1401

 

 

Synthesis and crystal structures of bismuth(III) complexes with dithiocarbamate [Bi(S2CNEt2)3]2 and [Bi(S2CNC4H8)2(NO3)][1,10-Phen]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Han Dong Yin*, Min Hong & Chuan Hua Wang

 

 

 

 

 

[Bi(S2CNEt2)3]2

 

[Bi(S2CNEt2)3]2 has each Bi atom as seven coordinated with a distorted pentagonal bipyrimidal geometry. In [Bi(S2CNC4H8)2(NO3)][1,10-Phen], the bismuth atom is eight coordinated in a capped distorted pentagonal bipyrimidal geometry.

 

1406

 

 

Efficient removal of arsenic from polluted ground water by using a layered double hydroxide exchanger

 

 

 

A Bhaumik *, S Samanta & N K Mal

 

 

 

Arsenic concentration in polluted ground water has been reduced to a permissible limit (~0.02 mg/l) employing the intercalation behavior of layered double hydroxide Mg-Al hydrotalcite. The efficiency of arsenic removal from contaminated ground water is improved by pre-treatment with a small amount of dilute aqueous H2O2 to oxidize As(III) to As(V) under acidic pH conditions followed by its exchange with hydrotalcite.

 

 

1410

 

 

Micellar spectrofluorimetric determination of lead(II) in natural water, waste water and egg samples with N-(2˘-pyridyl)-2-hydroxybenzamide

 

 

 

B S Garg*, N Bhojak & Deo Nandan Kumar

 

 

 

A sensitive, convenient and rapid spectrofluorimetric method for determination of lead(II) with N-(2˘-pyridyl)-2-hydroxy­benzamide in Brij-35 micellar medium has been developed. The calibration graph is linear over the range 0.2-2 µg /ml Pb(II). The method has been satisfactorily applied for the determination of lead(II) in natural water, waste water and egg samples.

 

 

1413

 

Column preconcentration and spectro-photometric trace determination of Ziram and Zineb using chitin as an adsorbate

 

 

 

Sanjiv Kumar Mehta, Ashok Kumar Malik,Usha Gupta, Baldev Singh & A L J Rao*

 

 

 

A new method has been developed for the determination of Ziram and Zineb present in a large volume of aqueous solution by complex formation on a natural polymer chitin loaded with 4-(2´-pyridylazo)resorcinol.

 

Authors for correspondence are indicated by (*)

 

 


Indian Journal of Chemistry

Vol. 44A, July 2005, pp. 1333-1338

 

Determination of potential energy function and transport properties of sulphur hexafluoride

Elaheh K Goharshadi*, Masoud Nahali & Mahmood Baherololoom

Received 25 April 2004; accepted 31 March 2005

The potential energy function of sulphur hexafluoride has been determined via the inversion of reduced viscosity collision integrals at zero pressure and fitted to obtain an analytical potential form. A comparison of the potential with the previously determined potential has been included. The interaction potential energy from the inversion procedure reproduces, within experimental error, viscosity, self-diffusion coefficient, thermal conductivity and isotopic thermal diffusion factor of sulphur hexafluoride over a wide temperature range. These properties have also been fitted to very accurate equations.

 

Indian Journal of Chemistry

Vol. 44A, July 2005, pp. 1339-1344

 

Calculation of the second virial coefficients of non-spherical molecules in binary mixtures

Fariba S Hashemi*, Ezat Keshavarzi & Parvaneh Maleki

Received 16 November 2004; revised 3 May 2005

The second virial coefficients for simple molecular gases and their mixtures of non-spherical molecules have been calculated through a revised analysis of the effect of long-range non-spherical terms in the intermolecular potential functions. The auxiliary functions in the perturbation terms for calculating the non-spherical contributions have been calculated numerically and tabulated over a wide range of temperatures. Hartree-Fock dispersion individually damped (HFDID1) potential has been used as a core potential to calculate both the spherical and non-spherical contributions to the second virial coefficient of N2, O2, CO, and CO2. The cross-virial coefficients in the mixtures of those molecules among themselves and with the noble gas (Ar) are predicted with excellent agreement with experimental values. The results for pure gases show that the calculations are in good agreement with the experimental data. Examination of the deviation plots show that the calculated values for the interaction second virial coefficients are in good agreement with the experimental values over the whole range of temperatures and also reported values.

 

Indian Journal of Chemistry

Vol. 44A, July 2005, pp. 1345-1354

 

One pot acetalization of ketones with methanol over rare earth metal exchanged NaFAU-Y zeolites

Bejoy Thomas & S Sugunan*

Received 17 January 2005; revised 5 May 2005

Aromatic ketones (acetophenone and benzophenone) as well as the cyclic ketone (cyclohexanone) can be converted to their corresponding dimethyl acetal in near quantitative yields at ambient or refluxing temperatures by reacting with methanol. Large pore zeolites H-Y, Na-Y, different rare earth exchanged Na-Y zeolites, mesoporous K-10 montmorillonite clay, and silica have been used as catalysts. Molecular sizes of the ketones are critical in deciding the acetalization ability over any catalysts. Zeolites undergo fast deactivation as evidenced by reaction time studies. These catalysts are poisoned by water (especially at low temperatures used in the present study) and the reaction will stop as soon as sufficient water is produced in the reaction to fully poison the catalyst. The activity of ketones follows the order: cyclohexanone> acetophenone> benzophenone, which is the reverse order of molecular size. The electron withdrawing property of phenyl groups is also important in decreasing the reactivity of acetophenone and benzophenone. The optimum number of acidic sites as well as dehydrating ability of K-10 montmorillonite clay and various rare earth exchanged Na-Y zeolites seem to work well in shifting the equilibrium to the product side. The method provides an efficient, simple and eco-friendly protocol for synthesizing dimethyl acetals.

IPC Code: Int. Cl.7 B01J29/08

 

Indian Journal of Chemistry

Vol. 44, July 2005, pp. 1355-1358

 

Polyethylene glycol degradation by UV irradiation

 

Ishwar Das* & Sujeet Kumar Gupta

Received 29 January 2004; revised 11 March 2005

Degradation of polyethylene glycol has been studied by UV irradiation. A drastic change in the morphology from spherulite to rhythmic pattern has been observed under polarized light microscope when exposed to UV light. Molecular weight of PEG, Rf value and melting point have been recorded after UV exposure. On UV exposure there has also been a change in UV, IR and powder X-ray diffraction pattern.

IPC Code: Int. Cl.7 C08L23/06; C08J7/18

 

Indian Journal of Chemistry

Vol. 44A, July 2005, pp. 1359-1364

 

Kinetic study of the addition reaction of carbon tetrachloride to 1-hexene initiated by chromium hexacarbonyl in the presence of UV light

 

A Harfoush

Received 11 January 2005; revised 18 April 2005

Addition reaction of CCl4 to the double bond of olefin (particularly 1-hexene) in the presence of Cr(CO)6 and light has been investigated. The reaction follows, mainly, a free radical chain route in which the metal complex acts solely as an initiator. The observed orders of reaction clearly demonstrate that the reaction proceeds by a free radical chain route. The effect of UV light has been studied and found to be responsible for the initiation of the free radical chain process and for the preparation of photocatalytic species, which are photolabile and responsible for the formation of a small amount of the addition reaction product during the dark periods. Cr(CO)6 shows initiation efficiency comparable with organic peroxides, but other complexes, Mo(CO)6, W(CO)6, are less efficient.

IPC Code: Int. Cl.7 C07B37/02

Indian Journal of Chemistry

Vol. 44A, July 2005, pp. 1365-1371

 

Densities and viscosities of binary liquid systems of acetonitrile with aromatic ketones at 308.15 K

 

T Savitha Jyostna & N Satyanarayana*

Received 25 November 2004; revised 31 March 2005

The densities and viscosities for the binary mixtures of acetonitrile + aromatic ketones (acetophenone, propiophenone, paramethyl acetophenone and parachloro acetophenone) at 308.15 K over the entire range of composition are reported here. The densities and viscosities have been used to calculate the excess molar volumes and deviations in viscosity. The excess molar volumes and deviations in viscosity are fitted to a Redlich-Kister type equation. Other parameters like excess Gibbs free energy of activation of viscous flow and Grunberg-Nissan interaction constant are also utilized in the qualitative analysis to elicit the information on the nature of the bulk molecular interactions of acetonitrile + aromatic ketone binary mixtures.

IPC Code: Int. Cl.7 G01N

Indian Journal of Chemistry

Vol. 44A, July 2005, pp. 1372-1377

 

Spectroscopic studies on charge transfer complexes of
1,4,10,13-tetraoxa-7,16-diazacyclooctadecane with a series of electron acceptors

Akmal S Gaballa

Received 9 November 2004; accepted 30 April 2005

The interaction of the mixed oxygen-nitrogen cyclic base 1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (D18C6) with various π-acceptors, picric acid (HPA), chloranilic acid (H2CA) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) has been studied spectrophotometrically in CHCl3 and MeOH at 25°C. The obtained complexes have been formulated as [(D18C6H2)(PA)2], [(D18C6H2)(CA)] and [(D18C6)(DDQ)]. The electronic absorption, 1H NMR and infrared spectra of the obtained complexes indicate a strong interaction between the donor and acceptors associated with a proton migration from HPA and H2CA to the donor followed by intramolecular hydrogen bonding. The equilibrium constants, KC, for the complexes are shown to be dependent on the structure of the used acceptors.

IPC Code: Int. Cl.7 C07C59/00; G01N21/00

 

Indian Journal of Chemistry

Vol. 44A, July 2005, pp. 1378-1382

 

Application of proton induced X-ray emission (PIXE) in estimation of trace metals entrapped in silica matrix

P K Jal, M Sudarshan, A Saha, Sabita Patel & B K Mishra*

Received 27 November 2002; revised 9 May 2005

Proton induced X-ray emission technique is used for multielemental analysis of metal ions adsorbed on nanosilica surface. At pH 3.5, silica traps uranium selectively from a mixture of solutions of 13 different metal ions viz., K(I), Ca(II), Fe(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Sr(II), Cd(II). Ba(II), Hg(II) and UO2(VI).

IPC Code: Int. Cl.7 G01N21/00

 

Indian Journal of Chemistry

Vol. 44A, July 2005, pp. 1383-1387

 

Synthesis and characterization of a new phase of stannic arsenate ion exchanger and its use in TLC separations of metal ions

Syed Ashfaq Nabi* & Amjad M T Khan

Received 16 August 2004; revised 15 March 2005

A new phase of inorganic ion exchanger, stannic arsenate, has been synthesized by mixing solution of stannic chloride pentahydrate (0.2 M) with  sodium arsenate solution (0.4 M) in the volume ratio 3:1 at pH 0.40.  The ion exchange capacity of the material for Ba2+ has been found to be 2.73 meq/g of dry exchanger. Chemical and thermal stabilities, chemical composition, pH titrations, FTIR, TGA, DSC and X-ray studies of the material have been studied. The ratio of the material is found to be Sn : As :: 0.28 : 0.30 (mmoles). On the basis of RF values in polar and mixed solvents systems, important binary, ternary and quantitative separations of metal ions have been achieved on stannic arsenate cellulose layer. The practical utility of this material has been demonstrated by achieving separations and determinations of metal ions in glass industry waste.

IPC Code: Int. Cl.7 B01J39/02

Indian Journal of Chemistry

Vol. 44A, July 2005, pp. 1388-1391

 

Studies on B-site doped LaSrCoO4 mixed oxides towards CO and C3H8 oxidation

Laitao Luo*, Guangxin Shao & Zhanhui Duan

Received 19 November 2004; revised 16 March 2005

 

A series of LaSrCo0.9B′0.1O4 (B′= Mn, Fe, Ni, Cu) mixed oxides have been prepared by the polyacrylamide gel method and used successfully for CO and C3H8 oxidation. The results show that the specific effects of B′ ions on CO and C3H8 oxidation depend on their category. In comparison to the LaSrCoO4 catalyst, the activity of LaSrCo0.9Ni0.1O4 catalyst for CO and C3H8 oxidation is higher, while the activity of Mn, Fe or Cu-doped catalysts is lower. The TPD and XRD analyses show that the increase in oxidation activity of LaSrCo0.9Ni0.1O4 catalyst towards CO and C3H8 oxidation can be related to the increase in O2-adsorption, CO2-desorption quantity and the lattice distortion.

IPC Code: Int. Cl.7 B01J23/00; B01J37/00

Indian Journal of Chemistry

Vol. 44A, July 2005, pp. 1392-1394

 

KMnO4-Al2O3 as a highly efficient and mild catalyst for regeneration of carbonyl compounds from hydrazones in the solid state

G H Imanzadeh Karkaragh* & H Eskandari

Received 19 July 2004; revised 20 April 2004

A simple and selective method for the conversion of hydrazones to the corresponding carbonyl compounds is described here using KMnO4-Al2O3 under solvent-free conditions. Regeneration reaction of carbonyl compounds from hydrazones takes place at room temperature in a few minutes in almost quantitative yield.

ICP Code: Int. Cl.7 B01J8/00; C07C45/00

Indian Journal of Chemistry

Vol. 44A, July 2005, pp. 1395-1397

 

Development of electrochemical supercapacitors using underpotential deposition of thallium on silver

T C Girija & M V Sangaranarayanan*

Received 15 July 2004; revised 21 March 2005

The design of electrochemical supercapacitors exploiting the concept of underpotential deposition (UPD) is demonstrated using the UPD of thallium on silver as an illustrative example. The specific capacitance is deduced as 3.45´102 Farads g-1 from cyclic voltammetric studies employing the roughness factor for calculating the electroactive surface area.

IPC Code: Int. Cl.7 H01G

 

Indian Journal of Chemistry

Vol. 44A, July 2005, pp. 1398-1400

 

QSAR studies on pyrrolo (2,1-d) (1,2,3,5)tetrazinones, a new class of azolotetrazines

Girish Tripathi & J P Mishra*

Received 31 January 2005; revised 15 March 2005

Quantitative structure activity relationship (QSAR) has been performed on some pyrrolo (2,1-d) (1,2,3,5) tetrazinone series of antitumour drugs, using physico-chemical parameters such as equalized electronegativity, Xeq, molecular connectivity, IXb, and hydrophobicity, logP. Anticancer activity of these compounds in COLO-205 cancer cell has been found to correlate well with Xeq. The presence of –CONH2 function is found to be important for activity.

IPC Code: Int. Cl.7: C07D257/12

 

Indian Journal of Chemistry

Vol. 44A, July 2005, pp. 1401-1405

 

Synthesis and crystal structures of bismuth(III) complexes with dithiocarbamate [Bi(S2CNEt2)3]2 and [Bi(S2CNC4H8)2(NO3)][1,10-Phen]

 

Han Dong Yin*, Min Hong & Chuan Hua Wang

Received 17 January 2005; revised 5 May 2005

Two novel bismuth(III) complexes with dithiocarbamate, [[Bi(S2CNEt2)3]2 (1) and [Bi(S2CNC4H8)2(NO3)]·[1,10-Phen] (2) have been synthesized. The crystal structures have been determined by X-ray single crystal diffraction. The crystals of complex 1 belong to monoclinic with space group P21/c, a = 12.625(2), b = 13.628(3), c = 14.835(3) Ĺ, b = 100.002(2)o, Z =2, V = 2513.7(8) Ĺ3, Dc = 1.727 mg/m3, μ= 7.517 mm1, F(000) = 1280, R =0.0306 and wR =0.0818. In this binuclear complex, the two Bi atoms are seven-coordinated, and each of the two atoms has distorted pentagonal bipyramidal geometry. Each of central Bi atoms is surrounded equatorially by five S atoms and axially by two S atoms. Two of the six bidentate ligands are bridged in such a way that each sulfur atom is simultaneously bonded to both Bi atoms. The crystals of complex 2 belong to triclinic with space group Pī, a = 10.10(3), b = 10.43(3), c = 13.52(3) Ĺ, α=79.71(4), β=85.67(4), γ=66.29(4)o, Z=2, V=1284(5) Ĺ3, Dc=1.924 mg/m3, μ=7.227 mm-1, F(000)=724, R=0.0656, wR=0.0997. In this complex, the bismuth atom is eight-coordinated in a capped distorted pentagonal bipyramidal geometry. Around the central Bi atom, three S atoms and two N atoms occupy equatorial positions and one S atom and one O atom occupy axial positions.

IPC Code: Int. Cl.7  C07F9/94; G01N23/22

Indian Journal of Chemistry

Vol. 44A, July 2005, pp. 1406-1409

 

Efficient removal of arsenic from polluted ground water by using a layered double hydroxide exchanger

A Bhaumik*, S Samanta & N K Mal

Received 17 November 2003; revised 28 April 2005

Arsenic concentration in the polluted ground water has been sufficiently reduced from its alarming limit to a permissible one (~0.02 mg/l) employing the intercalation behaviour of Layered Double Hydroxide (LDH) Mg-Al hydrotalcite. The exchange reaction was very simple and the efficiency of the process remained almost same in many cycles. This efficiency of arsenic removal from contaminated ground water has been drastically improved by pre-treatment with a small amount of dilute aqueous H2O2 to oxidize As(III) to As(V) under acid pH condition  followed by its exchange with hydrotalcite. After few exchange cycles the solid exchanger could be easily exchanged with a saturated NaCl solution to regenerate the LDH for further use.

IPC Code: Int. Cl.7 B01J39/02; C07F1/42

Indian Journal of Chemistry

Vol. 44A, July 2005, pp. 1410-1412

 

Micellar spectrofluorimetric determination of lead(II) in natural water, waste water and egg samples with N-(2˘-pyridyl)-2-hydroxybenzamide

B S Garg*, N Bhojak & Deo Nandan Kumar

Received 10 October 2004; revised 11 February 2005

A sensitive, convenient and rapid spectrofluorimetric method for determination of lead(II) with N-(2˘-pyridyl)-2-hydroxy­benzamide in a Brij-35 micellar medium has been developed. The calibration graph is linear over the range 0.2-2 µg/ml Pb(II) with regression coefficient of 0.9997 and relative standard deviation 2.9%. The method is relatively free from interference and satisfactorily applied for the determination of lead(II) in natural, waste water and egg samples.

IPC Code: Int. Cl.7 C07F1/00; C07C233/65

 

Indian Journal of Chemistry

Vol. 44A, July 2005, pp. 1413-1414

 

Column preconcentration and spectrophotometric trace determination of Ziram and Zineb using chitin as an adsorbate

Sanjiv Kumar Mehta, Ashok Kumar Malik, Usha Gupta, Baldev Singh & A L J Rao*

Received 30 September 2004; revised 15 March 2005

A new method has been developed for the determination of Ziram and Zineb present in a large volume of aqueous solution by complex formation on a natural polymer chitin loaded with 4-(2´-pyridylazo)resorcinol. Ziram/Zineb is quantitatively retained on the column and exchange the zinc present in them with PAR in the pH range 9.0-12.5 at a flow rate of 1-10 ml/min. The complex adsorbed on chitin is eluted from the column with 10 ml of dimethylformamide and absorbance of the eluate measured at 490 nm against a reagent blank. The molar absorptivity is found to be 9.2 ´ 104 l mol-1cm-1. Sandell’s sensitivity for Ziram and Zineb is found to be 0.0033 and 0.0029 µg cm-2, respectively. The method can be applied for the determination of Ziram and Zineb in synthetic, commercial samples and in various foodstuffs.

IPC Code: Int. Cl.7 G01N21/00